Signaling of the New York City Subway#Automation

The New York City Subway system has, for the most part, used block signaling since its 1904 opening. {{As of|May 2014}}, the system consists of about 14,850 signal blocks, 3,538 mainline switches, 183 major track junctions, 10,104 automatic train stops, and 339,191 signal relays. Fixed-block signals are used on about 85% of the subway system {{As of|2025|lc=ylc}}.{{Cite news |last=Hu |first=Winnie |last2=Chen |first2=Stefanos |last3=Weingart |first3=Eden |last4=Cenicola |first4=Tony |date=2025-04-20 |title=An Inside Look at the NYC Subway’s Archaic Signal System |url=https://www.nytimes.com/interactive/2025/04/20/nyregion/nyc-subway-signals.html |access-date=2025-04-21 |work=The New York Times |language=en-US |issn=0362-4331}} Trains used to be controlled by signal towers at interlockings, but this was eventually phased out in favor of master towers.{{Cite AV media|url=https://www.youtube.com/watch?v=Mjx3S3UjmnA|title=CBTC: Communications-Based Train Control|date=July 20, 2015|author=Metropolitan Transportation Authority|type=video|language=en-US|via=YouTube|access-date=April 30, 2018}} Eventually, these master towers were replaced by a single rail control center: the New York City Transit Power Control Center in Midtown Manhattan.{{Cite web|url=http://untappedcities.com/2011/08/08/the-most-powerful-block-in-nyc-that-youve-never-heard-of/|title=The Most Powerful Block in NYC That You've Never Heard Of|date=August 8, 2011|website=Untapped Cities|access-date=September 13, 2016}}

These signals work by preventing trains from entering a "block" occupied by another train. Typically, the blocks are {{convert|1000|ft}} long, although some highly used lines, such as the IRT Lexington Avenue Line, use shorter blocks. Insulators divide the track segments into blocks. The two traveling rails form a track circuit, as they conduct electric current. If the track circuit is open and electricity cannot travel between the rails, the signal will light up as green, as it is unoccupied by a train. When a train enters the block, the metal wheels close the circuit on the rails, and the signal turns red, marking the block as occupied. The train's maximum speed will depend on how many blocks are open in front of it. However, the signals do not register the trains' speed, nor do they register where in the block the train is located. If a train passes a red signal, the train stop automatically engages and activates the brakes.{{cite news |last=Somers |first=James | title=Why New York Subway Lines Are Missing Countdown Clocks |work=The Atlantic | date=November 13, 2015 |url=https://www.theatlantic.com/technology/archive/2015/11/why-dont-we-know-where-all-the-trains-are/415152/ | access-date=May 20, 2016}}

The New York City Subway generally distinguishes its current signals between automatic signals, which are solely controlled by train movements; approach signals, which can be forced to display a stop aspect by the interlocking tower; home signals, whose route is set by the interlocking tower; and additional signals (such as call-on, dwarf, marker, sign, repeater and time signals).{{rp|110–111}}{{Cite web|url=http://www.hts4u.com/documents/rulesbook%5B1%5D.pdf|title=Rules & Regulations Governing Employees of MTA New York City Transit, Manhattan and Bronx Surface Transit Operating Authority and South Brooklyn Railway|date=November 2003|website=hts4u.com|publisher=Metropolitan Transportation Authority|access-date=April 24, 2018}}{{rp|Chapter 2}}

Common automatic and approach signals consist of one signal head showing one of the following signal aspects:

• stop (one red light); with special rules for call-on and timer signals{{rp|110–111}}{{rp|68}}
• clear, next signal at clear or caution (one green light){{rp|110–111}}{{rp|68}}
• proceed with caution, be prepared to stop at next signal (one yellow light){{rp|110–111}}{{rp|68}}

Where different directions are possible, the subway uses both speed and route signaling. The upper signal head indicates the speed while the lower signal head is used for routes, with the main route shown in green and the diverging route shown in yellow.{{rp|110–111}}{{rp|75–77}}

The old signals break down more easily, since some signals have outlasted their 50-year service life by up to 30 years, and signal problems accounted for 13% of all subway delays in 2016.{{Cite news |url=https://www.nytimes.com/2017/05/01/nyregion/new-york-subway-signals.html|title=Key to Improving Subway Service in New York? Modern Signals |last=Fitzsimmons |first=Emma G.|date=May 1, 2017 |newspaper=The New York Times |access-date=May 2, 2017|issn=0362-4331|url-access=limited}} Additionally, some subway services have reached their train capacity limits and cannot operate extra trains with the current Automatic Block Signaling system.

The following indications are used for blocks where there are no track divergences (i.e. junctions) in the block immediately ahead.{{rp|73–84}}

TTC-signal-block-green.svg|Proceed{{rp|page=79}}|alt=Proceed

TTC-signal-block-yellow.svg|Proceed with caution, next signal is currently red{{rp|page=79}}|alt=Proceed with caution, next signal is currently red

TTC-signal-block-red.svg|Stop. Passing this signal trips the train stop{{rp|page=79}}|alt=Stop. Passing this signal trips the train stop

NYCT-signal-block-yellow-S.svg|Two-shot grade time signal, next signal is red only due to grade timing{{rp|page=79}}|alt=Two-shot grade time signal, next signal is red only due to grade timing

NYCT-signal-block-yellow-D.svg|Two-shot grade time signal, next signal is a home signal set to diverge and is red only due to grade timing{{rp|page=79}}|alt=Two-shot grade time signal, next signal is a home signal set to diverge and is red only due to grade timing

TTC-signal-block-red-lunar.svg|One-shot grade time signal, timer has not yet run out.{{rp|pages=73, 82}}|alt=One-shot grade time signal, timer has not yet run out.

NYCT-signal-block-red-20.svg|Station timer signal, signal will clear if approached at the displayed speed.{{rp|pages=73, 82}}|alt=Station timer signal, signal will clear if approached at the displayed speed.

Older signals on the former IRT lines may use different indications, which are not shown.{{rp|73, 77–78}} The lights on the older IRT signals, from top to bottom, were green, red, and yellow. The lights on current signals, from top to bottom, are green, yellow, and red.{{rp|110–111}}

File:Bowling_Green_NYCS_signal-1.jpg station.]]

The system also has automatic and manual "key-by" red signals where the conductor can insert a physical key into the wayside block signal, changing the signal indication from red to yellow. The signals involve the operation of an automatic stop with an automatic or manual release, then to proceed with caution, with preparations to stop in case of debris or other obstructions on the track.{{rp|xiv}}{{rp|40–41}}

Until 1970, when a train paused at a red block signal the train operator was allowed to pass the red signal by keying-by. That is, the train operator pauses at the red signal and then gets out of the cab, descends to the tracks' level, and cranks down the track trip with a key-like device.{{rp|xiv}}{{rp|178}} After a series of accidents in which train operators keyed by and crashed into trains in front, including a crash north of the Hoyt–Schermerhorn Streets station in 1970,{{Cite news|last=Montgomery|first=Paul L.|date=July 18, 1970|title=37 Hurt in Crash of Two IND Trains|language=en-US|work=The New York Times|url=https://www.nytimes.com/1970/07/18/archives/37-hurt-in-crasn-of-two-ind-trains-one-rams-rear-of-another-in.html|access-date=June 21, 2022|issn=0362-4331|url-access=subscription}} the procedure was banned unless permission was granted by the train dispatchers.{{rp|xiv}}{{Cite news |url=https://www.nytimes.com/1997/11/22/nyregion/inquiry-into-subway-crash-focuses-on-misplaced-sign.html |title=Inquiry Into Subway Crash Focuses on Misplaced Sign |last=Newman |first=Andy |date=November 22, 1997|newspaper=The New York Times|issn=0362-4331|access-date=July 17, 2016|url-access=limited}}{{Cite book|url=https://archive.org/details/undersidewalksof00cuda|url-access=registration|title=Under the Sidewalks of New York: The Story of the Greatest Subway System in the World|last=Cudahy|first=Brian J.|date=1995|publisher=Fordham Univ Press|isbn=9780823216185|language=en|access-date=April 30, 2018}}{{Rp|178}}{{Cite web|url=https://www.ntsb.gov/news/press-releases/Pages/Oversight_Design_Problems_Cited_in_NYCs_Subway_Crash.aspx|title=Oversight, Design Problems Cited in NYC's Subway Crash|date=March 19, 1996|website=ntsb.gov|access-date=July 17, 2016}}

Speed control on the subway is ensured by "time signals". A timer, counting up, is started as soon as the train passes a certain point and will clear the signal ahead as soon as the predefined time elapsed. The minimum time is calculated from the speed limit and the distance between start of timer and signal. "Time signals" are distinguished into "grade timers" for speed supervision at grades, curves or in front of buffer stops, and "station timers" to allow one train to enter a station just as another is leaving, as long as these trains are going at a reduced speed. There are two types of grade-time signals. The first type, "two-shot timers", are generally used on down grades where the train must be under a set speed for a longer length of track. They are so named because a train operator would have two chances, or "shots", to pass the signal within the posted speed limit. "One-shot timers", on the other hand, are found at sharp curves, and are named because the operator only has one chance to pass the signal within the speed limit.{{Cite web |url=http://www.thejoekorner.com/out-the-front/index-signals.shtm|title=The JoeKorNer – Looking out the Front – Signals |last=Korman|first=Joe|website=thejoekorner.com|access-date=February 12, 2017}}

"Repeater signals" are also used to maintain safe train operation around curves. These signals repeat the indication of a signal up ahead around a curve, and are located on the opposite side of the track from the signals they repeat.{{rp|111}}

Another addition to the system's transit signals are "Wheel Detectors". These are sensors that can determine how fast a train is moving based on how quickly the axles of a given car are moving. First introduced in 1996 at interlockings, they further enforce the speed at which a train is traveling through an interlocking, and they are only active when a switch is set to the divergent route. Wheel detectors prevent train operators from running slowly at the beginning of a grade timing segment and then increasing the speed beyond the allowable limit without being tripped. When the indication is flashing, the train is too fast and is about to be tripped.{{rp|xv}}

"Gap filler signals" are used at the 14th Street–Union Square station on the IRT Lexington Avenue Line. They were formerly used at the Brooklyn Bridge–City Hall station on the IRT Lexington Avenue Line, the South Ferry Loop station on the IRT Broadway–Seventh Avenue Line, and the Times Square–42nd Street station on the 42nd Street Shuttle. These stations are part of the A Division, which consists of lines built by the Interborough Rapid Transit Company (IRT). At these stops, gap fillers extend out from the platforms to bridge the space between the platform and the car body and door at the curved stations. The signal consists of a single red lamp and a "GF" indicator underneath. When the signal is red, the gap fillers are extended, and when the red light is no longer lit up, the gap fillers have been retracted, and the train operator can increase the speed of the train and leave the station.{{rp|xv}}{{rp|86}}

Interlockings consist of two or more tracks that are connected by railroad switches; routes typically may conflict at these locations. They are arranged in a specific way, with switches and signals that prevent conflicting movements once one route is set up. Interlocking signals are fixed signals within an interlocking, containing two separate green-yellow-red signal heads and often other indications. A home signal is defined as an interlocking signal at the entrance to a route or block to control trains entering that route or block. Most interlockings only have one controlled signal on each track.{{rp|xii}}{{rp|75}} Some home signals contain a third, yellow aspect, on the bottom, and are known as "call-on" signals. These signals allow the train operator to press a lever near the signal to lower the trip arm, allowing the train to pass the signal at slow speed even if the signal is displaying a red light.{{rp|xiv}}{{rp|page=79}} Similar signals can be found in yards. The three aspects on these signals, when all displaying yellow, allow the train operator to go past the signal at a slow speed without stopping the train.{{rp|xiv}}

Interlocking signals are controlled by human operators in a signal tower near the switches, not by the trains themselves. A train operator must use a punch box, which is located besides the cab window in the station closest to the interlocking, to notify the switch operator of which track the train needs to go to. The switch operator has a switchboard in their tower that allows them to change the switches.{{rp|xii}}{{rp|74}}

Interlocking signals also tell train operators which way switches on the subway are set. The top part of an interlocking signal indicates the condition of the block ahead, while the lower part indicates the route selected. The following interlocking signals are used on the New York City Subway:{{rp|110–111}}{{rp|76–78}}

TTC-signal-interlocking-green-green.svg|Proceed, switch set to straight{{rp|page=76}}|alt=Proceed, switch set to straight

TTC-signal-interlocking-yellow-green.svg|Proceed with caution, switch set to straight, next signal is currently red{{rp|page=76}}|alt=Proceed with caution, switch set to straight, next signal is currently red

NYCT-signal-interlocking-green-yellow.svg|Proceed, switch set to diverge{{rp|page=76}}|alt=Proceed, switch set to diverge

TTC-signal-interlocking-yellow-yellow.svg|Proceed with caution, switch set to diverge, next signal is currently red{{rp|page=76}}|alt=Proceed with caution, switch set to diverge, next signal is currently red

TTC-signal-interlocking-red-red.svg|Stop and stay{{rp|page=76}}|alt=Stop and stay

TTC-signal-interlocking-red-red-callon.svg|Call on (train has been given permission to pass red signal){{rp|page=79}}|alt=Call on (train has been given permission to pass red signal)

NYCT-signal-interlocking-yellow-S-green.svg|Two-shot grade time signal, switch set to straight, next signal is red only due to grade timing{{rp|pages=76, 82}}|alt=Two-shot grade time signal, switch set to straight, next signal is red only due to grade timing

NYCT-signal-interlocking-yellow-S-yellow.svg|Two-shot grade time signal, switch set to diverge, next signal is red only due to grade timing{{rp|pages=76, 82}}|alt=Two-shot grade time signal, switch set to diverge, next signal is red only due to grade timing

NYCT-signal-interlocking-yellow-D-green.svg|Two-shot grade time signal, switch set to straight, next signal is a home signal set to diverge and red only due to grade timing{{rp|pages=76, 82}}|alt=Two-shot grade time signal, switch set to straight, next signal is a home signal set to diverge and red only due to grade timing

NYCT-signal-interlocking-yellow-D-yellow.svg|Two-shot grade time signal, switch set to diverge, next signal is a home signal set to diverge and red only due to grade timing{{rp|pages=76, 82}}|alt=Two-shot grade time signal, switch set to diverge, next signal is a home signal set to diverge and red only due to grade timing

NYCT-signal-interlocking-red-lunar-red.svg|One-shot grade time signal, timer has not yet run out{{rp|pages=75, 81}}|alt=One-shot grade time signal, timer has not yet run out

NYCT-signal-interlocking-red-20-red.svg|Station timer signal, signal will clear if approached at the displayed speed.{{rp|page=83}}|alt=Station timer signal, signal will clear if approached at the displayed speed

Until the DeKalb Avenue junction's reconstruction in 1958, there was a three-way switch at that junction, the only one in the system. A special blue signal was used for the third option.

Another signal type is a "dwarf signal", which is often used at switches to allow for occasional movements against the usual direction of train traffic. Controlled manually from a tower, they are not part of ordinary operations, and they generally do not include trip arms.

On June 8, 1927, the New York State Transit Commission (NYSTC) ordered the Brooklyn–Manhattan Transit Corporation (BMT) to install automatic signals and automatic tripping devices on the remaining {{Convert|142|miles|km|abbr=}} of unsignalled local tracks. The NYSTC ordered the Interborough Rapid Transit Company to install automatic signals and automatic tripping devices on all {{Convert|183|miles|km|abbr=}} of unsignalled local tracks on June 29, 1927. The work was to estimated to cost $9,345,800 on the BMT, and $13,328,400 on the IRT. On March 16, 1931, the installation of signaling on the local tracks of the BMT Jamaica Line from 168th Street to Broadway Junction was complete. Work to install signaling on the IRT White Plains Road Line from Wakefield–241st Street to Gun Hill Road was completed on June 7, 1931, while the work on the elevated portion of the IRT Pelham Line was completed on August 5, 1931. The signal installation on the BMT Myrtle Avenue Line from Broadway to Metropolitan Avenue was completed on October 4, 1931. The signaling of the BMT Brighton Line was completed on December 16, 1931.{{Cite book|url=https://archive.org/details/annualreport1119newy/|title=Eleventh Annual Report For The Calendar Year 1931| year=1922 |publisher=New York State Transit Commission|pages=90–92}}

After a collision between two trains on the Williamsburg Bridge in 1995, in which a train operator was killed after speeding his train into the back of another, the MTA modified both signals and trains to lower their average speeds. Trains' maximum speeds were reduced from {{Convert|55|mph|kph}} to {{Convert|40|mph|kph}}, and the MTA installed grade-time signals around the system to ensure that a train could only travel under a certain maximum speed before it was allowed to proceed.{{cite web|url=https://www.villagevoice.com/2018/03/13/the-trains-are-slower-because-they-slowed-the-trains-down/|title=The Trains Are Slower Because They Slowed the Trains Down|last=Gordon|first=Aaron|date=March 13, 2018|website=The Village Voice|access-date=March 14, 2018}} Some of these time signals malfunctioned: they prevented trains from passing even if the operator had slowed down the train to the speed that was indicated, and so some operators slowed trains further in case a time signal forced trains to wait for longer than was indicated.{{Cite news|url=https://www.nytimes.com/interactive/2018/05/09/nyregion/subway-crisis-mta-decisions-signals-rules.html|title=How 2 M.T.A. Decisions Pushed the Subway Into Crisis|last=Pearce|first=Adam|date=May 9, 2018|work=The New York Times|access-date=May 9, 2018|language=en-US|issn=0362-4331|url-access=limited}} This resulted in overcrowded trains, since fewer trains per hour were able to proceed on certain sections of track.{{Cite news|url=https://www.nytimes.com/2017/11/18/nyregion/new-york-subway-system-failure-delays.html|title=How Politics and Bad Decisions Starved New York's Subways|last1=Rosenthal|first1=Brian M.|date=November 18, 2017|work=The New York Times|access-date=March 14, 2018|last2=Fitzsimmons|first2=Emma G.|language=en-US|issn=0362-4331|last3=LaForgia|first3=Michael|url-access=limited}} By 2012, over 1,200 signals had been modified, and of these, 1.1% (13 signals) caused passengers to spend 2,851 more hours on trains per weekday, compared to before the modifications. By mid-2018, the number of modified signals had grown to 1,800, before going up to 2,000 at years' end.{{Cite news|url=https://www.nytimes.com/2018/12/10/nyregion/new-york-subway-delay.html|title=Why Your Subway Train Might Start Moving Faster|last=Fitzsimmons|first=Emma G.|date=December 10, 2018|work=The New York Times|access-date=December 10, 2018|language=en-US|issn=0362-4331|url-access=limited}}

{{As of|2017}}, some of the oldest block signals in the system were 80 years old, and they broke down frequently, causing more delays and prompting the MTA to declare a state of emergency for the subway in 2017.{{cite web|url=http://www.nydailynews.com/new-york/nyc-subway-relies-decades-old-outmoded-signals-switches-article-1.3184666|title=NYC Subway Relies on Decades-Old, Outmoded Signals and Switches|last=Rivoli|first=Dan|date=May 22, 2017|website=New York Daily News|access-date=March 14, 2018}} An MTA investigation found that between December 2017 and January 2018, broken signals caused 11,555 train delays.{{Cite news|url=https://www.nytimes.com/2018/03/28/nyregion/subway-signals.html|title=How Often Do Subway Signals Fail? Ask Twitter|last=Nir|first=Sarah Maslin|date=March 28, 2018|work=The New York Times|access-date=March 30, 2018|language=en-US|issn=0362-4331|url-access=limited}} In summer 2018, New York City Transit started evaluating twenty places where signal timers affect service the most.{{Cite news|url=http://www.nydailynews.com/new-york/ny-metro-andy-byford-signals-delays-20180720-story.html#|title=Byford Vows to Speed up Trains, Cutting 10,000 Delays a Month – NY Daily News|last=Rivoli|first=Dan|date=July 22, 2018|work=New York Daily News|access-date=July 23, 2018|language=en-US}}

Speed limits have remained relatively unchanged even as improvements in track geometry and car design allow trains to operate at higher speeds. Where possible, the agency has sought to increase speed limits.{{Cite news|url=http://www.nydailynews.com/new-york/ny-metro-subway-signal-timers-20181026-story.html|title=MTA Tests Subway Signals, Plans Fixes to Get Trains Moving Faster – NY Daily News|last=Rivoli|first=Dan|date=October 29, 2018|work=New York Daily News|access-date=November 8, 2018|language=en-US}} In summer 2018, New York City Transit president Andy Byford created the SPEED Unit to reduce delays by modifying operating and service practices.{{Cite web|url=http://www.mta.info/press-release/nyc-transit/nyc-transit-begins-correcting-antiquated-speed-limits-fixing-faulty|title=NYC Transit Begins Correcting Antiquated Speed Limits & Fixing Faulty Signals as Part of 'Save Safe Seconds' Campaign to Safely Improve Subway Performance|date=December 10, 2018|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=December 10, 2018|archive-date=December 10, 2018|archive-url=https://web.archive.org/web/20181210214605/http://www.mta.info/press-release/nyc-transit/nyc-transit-begins-correcting-antiquated-speed-limits-fixing-faulty|url-status=dead}} Soon after, the MTA began testing timers as part of the first systemwide review of timers to determine whether they are allowing trains to run at the posted maximum speed. The MTA eventually identified 267 faulty timer signals that disallowed trains from proceeding at the speed limit, and thus, forced trains to run significantly slower than intended.{{cite web|url=https://www.wsj.com/articles/new-york-city-subway-trains-to-double-speed-on-some-stretches-1544487785|title=New York City Subway Trains to Double Speed on Some Stretches|last=Berger|first=Paul|date=December 11, 2018|website=The Wall Street Journal|url-access=subscription|access-date=December 11, 2018}}{{cite web|url=http://www.ny1.com/nyc/all-boroughs/news/2018/12/11/mta-raises-subway-speed-limits-after-fixing-dozens-of-faulty-signal-timers|title=MTA Raises Subway Speed Limits After Fixing Dozens of Faulty Signal Timers|last=Martinez|first=Jose|date=December 11, 2018|website=Spectrum News NY1 | New York City|access-date=December 11, 2018}} Train operators that pass the signals at or near their posted speeds have gotten punished due to the agency's strict discipline culture even though the signals are malfunctioning. Byford stated that "I don't think that safety and speed are incompatible."{{Cite web|url=http://www.ny1.com/nyc/all-boroughs/news/2018/11/08/mta-repairs-faulty-signal-timers-to-speed-up-subway-#|title=How the MTA Is Clocking Signal Timers To Speed Up Subway Service|last=Martinez|first=Jose|date=November 8, 2018|website=mta.info|publisher=Spectrum News NY1|access-date=November 8, 2018}} By December 2018, the SPEED Unit had found 130 locations where the speed limit could be increased, some of which were in the process of being fixed. It was also announced that speed limits would be doubled in some parts of the system, and that average speeds would generally be increased from {{Convert|10–20|mph|kph|abbr=on}} to {{Convert|40|mph|kph|abbr=on}}.{{cite web | title=MTA Raises Speed Limit On Subway Lines In Brooklyn, And Plans To Do The Same In All 5 Boroughs | website=CBS New York | date=December 10, 2018 | url=https://newyork.cbslocal.com/2018/12/10/speeding-up-subways/ | access-date=December 11, 2018}}{{Cite tweet|author=Vincent Barone|user=vinbarone|number=1072266646352482304|title=Here's a Chart Provided by the MTA Showing Where It's Made Speed Limit Changes in the Subways.|date=December 10, 2018|access-date=December 10, 2018}} In January 2019, it was announced that 95% of timers had been tested, and that the 320 faulty timers discovered were in the process of being fixed. In addition, 68 locations had been approved for increases in speed limits.{{Cite web|url=http://www.mta.info/press-release/nyc-transit/mta-new-york-city-transit-announces-progress-campaign-safely-speed-trains|title=MTA New York City Transit Announces Progress in Campaign to Safely Speed up Trains|date=January 21, 2019|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=January 21, 2019|archive-date=January 21, 2019|archive-url=https://web.archive.org/web/20190121220147/http://www.mta.info/press-release/nyc-transit/mta-new-york-city-transit-announces-progress-campaign-safely-speed-trains|url-status=dead}} The following month, the MTA hired subway-signal expert Pete Tomlin.{{cite web | last=Rivoli | first=Dan | title=World-renowned subway signal guru hired to speed up NYC's trains | website=New York Daily News | date=February 5, 2019 | url=https://www.nydailynews.com/new-york/ny-metro-signal-fast-forward-tomlin-20190204-story.html | access-date=February 5, 2019}}{{cite web | title=MTA's signal chief faces 'exciting,' 'difficult' task | website=am New York | date=February 5, 2019 | url=https://www.amny.com/transit/signal-problems-pete-tomlin-1.26910901 | access-date=February 5, 2019}} {{As of|March 2021}}, the MTA had increased speed limits at 64 locations since the preceding year.{{Cite web|last=Martinez|first=Jose|date=March 15, 2021|title=MTA Taps Need for Speed in Subways by Expanding Limits on Tracks|url=https://www.thecity.nyc/2021/3/15/22330165/subway-speed-rise-on-mta-train-tracks|access-date=March 23, 2021|website=THE CITY|language=en}}

{{Main|New York City Subway chaining}}

To precisely specify locations along the New York City Subway lines, a chainage system is used. It measures distances from a fixed point, called chaining zero, following the path of the track, so that the distance described is understood to be the "railroad distance," not the distance by the most direct route ("as the crow flies"). This chaining system differs from the milepost or mileage system. The New York City Subway system differs from other railroad chaining systems in that it uses the engineer's chain of {{convert|100|ft|m|2}} rather than the surveyor's chain of {{convert|66|ft|m|2}}. Chaining is used in the New York City Subway system in conjunction with train radios, in order to ascertain a train's location on a given line.{{cite web | title=New York City Subway CHAINING | website=The JoeKorNer Index | last = Korman | first = Joe | url=http://www.thejoekorner.com/out-the-front/chainall.htm | access-date=September 12, 2016}}

File:59 Street info board vc.jpg lines.]]

The New York City Subway uses a system known as Automatic Train Supervision (ATS) for dispatching and train routing on the A Division. The IRT Flushing Line, and the trains used on the {{NYCS trains|Flushing|type=service}}, do not have ATS for two reasons: they are isolated from the main-line A Division, and they were already planned to get communications-based train control (CBTC) before the ATS on the A Division, or ATS-A project, had started. ATS allows dispatchers in the Operations Control Center (OCC) to see where trains are in real time, and whether each individual train is running early or late. Dispatchers can hold trains for connections, re-route trains, or short-turn trains to provide better service when a disruption causes delays.{{cite web|url=http://www.mta.info/news/2012/12/28/know-you-go-mta-subway-time%E2%84%A2|title=Know Before You Go with MTA Subway Time|date=December 28, 2012|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=April 11, 2014|archive-date=March 12, 2015|archive-url=https://web.archive.org/web/20150312173309/http://www.mta.info/news/2012/12/28/know-you-go-mta-subway-time%E2%84%A2|url-status=dead}} ATS is used to facilitate the installation of train arrival displays, which count down the number of minutes until a train arrives, on the A Division and on the BMT Canarsie Line. ATS was first proposed for the BMT Canarsie Line and the A Division in 1992,{{Cite web|url=https://www.parsons.com/Media%20Library/0604_NYCT.pdf|title=Parsons Project of the Month—June 2004|date=June 2004|website=parsons.com|publisher=Parsons Corporation|archive-url=https://web.archive.org/web/20100215142105/https://www.parsons.com/Media%20Library/0604_NYCT.pdf|archive-date=February 15, 2010|url-status=dead|access-date=September 12, 2016}} after a 1991 derailment killed five people on a 4 train that derailed near the 14th Street–Union Square station.{{Cite news|url=https://www.nytimes.com/2017/08/21/nyregion/subway-signals-disruption.html|title=Fixing the Subway Requires Pain. But How Much, And for How Long?|last1=Santora|first1=Marc|date=August 21, 2017|work=The New York Times|access-date=August 23, 2017|last2=Tarbell|first2=Elizabeth|language=en-US|issn=0362-4331|url-access=limited}} CBTC for the Canarsie Line was proposed two years later.

The deployment of ATS-A involved upgrading signals to be compatible for future CBTC retrofitting, as well as consolidating operations from 23 different master towers into the Rail Control Center. Parsons Corporation helped the MTA install the system on the {{Convert|175|mi}} of A Division track, as well as doing some preliminary planning for ATS on the B Division. The project ended up costing $200 million. Its completion was delayed by five years, and it ultimately took 14 years to implement ATS-A.{{Cite web|url=https://www.fhwa.dot.gov/cadiv/segb/views/document/sections/section8/8_5_1.cfm|title=California Division: 8.5.1 New York City Transit Automated Train Supervision (ATS)|date=September 20, 2016|website=Federal Highway Administration (FHWA)|publisher=United States Department of Transportation; Federal Highway Administration|access-date=May 21, 2016}} However, ATS-A's deployment was delayed due to several issues. The unique specifications of New York City Subway's equipment, the MTA's choice to use its own workers rather than outside contractors, and the inadequate training of contractors all contributed to delays. In addition, the MTA kept missing deadlines for testing ATS. The single biggest issue during the project, though, was the fact that MTA and the contractors did not cooperate well, which was attributed mostly to poor communication.

In 2006, 2008, and 2010, the MTA considered upgrading the B Division to ATS, but dismissed the proposal because it was too complex and would take too long. However, the MTA stated that due to high customer demand for train arrival displays, it would use a combination of CBTC and a new system, named the "Integrated Service Information and Management" (abbreviated ISIM-B). The simpler ISIM-B system, started in 2011, would essentially combine all of the data from track circuits and unify them into digital databases; the only upgrades that were needed were to be performed on signal towers.{{Cite web|url=http://web.mta.info/mta/news/books/archive/120723_1400_CPOC.pdf|title=Capital Program Oversight Committee Meeting July 2012|date=July 23, 2012|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=March 29, 2018}}{{rp|9–10}} At the time, although the entire A Division had ATS, only seven lines of the B Division had a modernized control system (the IND Concourse Line, 63rd Street Lines, BMT Astoria Line, BMT Brighton Line, BMT Franklin Avenue Line, BMT Sea Beach Line, and BMT West End Line, as well as part of the IND Culver Line and the tracks around Queens Plaza).{{rp|12}} Originally slated to be completed by 2017,{{rp|20}} ISIM-B was later delayed to 2020.{{Cite news|url=https://www.wsj.com/articles/mta-board-approves-26-billion-capital-spending-plan-1446052998|title=More NYC Subway Countdown Clocks Won't Arrive Anytime Soon|last=Tangel|first=Andrew|date=October 28, 2015|newspaper=The Wall Street Journal|issn=0099-9660|access-date=May 21, 2016}} In 2015, the MTA awarded Siemens a contract to install a CBTC-compatible ATS system on most of the B division at a cost of $156,172,932. The contract excluded the Canarsie Line (which already had CBTC) and the IND Queens Boulevard Line and approaches (which was set to receive CBTC by 2021). The Queens Boulevard Line routes are served by the {{NYCS trains|Queens}}, but since the N, Q and W routes also share tracks with the R train in Manhattan, they will also have ATS installed. The cost of the ATS contract for the B division was later increased by $8.75 million.{{Cite web|url=http://web.mta.info/mta/news/books/archive/180319_1030_Transit.pdf|title=Transit and Bus Committee March 2018|date=March 19, 2018|website=mta.info|publisher=Metropolitan Transportation Authority|pages=155–156|access-date=March 29, 2018}}

File:34 St-Hudson Yards Station (21389427245).jpg station on the IRT Flushing Line, is being automated.]]

Trains using CBTC locate themselves based on measuring their distance in relation to fixed transponders installed between the rails. Trains equipped with CBTC have a transponder interrogator antenna beneath each carriage, which communicates with the fixed trackside transponders and report the trains' location to a wayside Zone Controller via radio. Then, the Controller issues Movement Authority to the trains. This technology upgrade allows trains to be operated at closer distances, slightly increasing capacity; allows the MTA to keep track of trains in real time and provide more information to the public regarding train arrivals and delays; and eliminates the need for complex interlocking towers. CBTC-enabled lines are controlled from the Operations Control Center in Midtown Manhattan, where 432 screens display the relative locations of trains. The trains are also equipped with computers inside the cab so that the conductor can monitor the train's speed and relative location.{{cite news| url = https://www.nytimes.com/2005/01/14/nyregion/14subway.html | title = Subways Run by Computers Start on L Line This Summer | access-date = May 24, 2007 | first=Sewell | last=Chan | author-link=Sewell Chan | date = January 14, 2005 | newspaper = The New York Times|url-access=limited}}{{Cite AV media|last=mtainfo|title=CBTC: Communications-Based Train Control|date=July 20, 2015|url=https://www.youtube.com/watch?v=Mjx3S3UjmnA|access-date=April 29, 2018}} The wayside controllers themselves are located in enclosed boxes that can withstand floods and natural disasters. The traditional block systems will remain on these lines despite the installation of CBTC.{{cite web | last=Luo | first=Michael | title=The Next Stop for the Subway Is a Fully Automated Future; Testing a Computer-Controlled Train Line | website=The New York Times | date=June 23, 2004 | url=https://www.nytimes.com/2004/06/23/nyregion/next-stop-for-subway-fully-automated-future-testing-computer-controlled-train.html | access-date=August 10, 2016|url-access=limited}}

File:Signal upgraded to 'flashing green' under CBTC.webm.]]

The block system handles all control and supervision of routes through interlockings including switch (point) control and switch status, for broken rail protection, and tracking of trains that are operating without CBTC. Lines equipped with CBTC are fully track-circuited with power frequency, single-rail track circuits. However, broken-rail protection is only guaranteed on one of the two rails of a track. Equipment aboard every train identifies the location of the train using wayside transponders as a basis. Once the Zone Controller has determined, based on track circuit information and train localization, that the CBTC train is a single discrete train, they use this information to grant movement authorities based on conditions ahead. The CBTC Zone Controller functions then as an overlay which only provides safe separation of trains and cannot do so without interaction from the Wayside (Legacy) Signaling system. Trains, with CBTC, can then operate closer together, although as before, platform dwell times and train performance are the true limiting factors in terms of headway performance. With the new system, signals and interlockings are still required, their job being done better by relay interlockings or Solid State Interlocking controllers. The ATS system at the Control Center is not a vital system and serves only to automate the routing of trains based on the overall timetable. The location of the train is also used to inform passengers of arrival times. The MTA's form of CBTC uses a reduced form of the old fixed-block signaling system, requiring that both be maintained at high cost.

Only newer-generation rolling stock that were first delivered in the early 2000s are designed for CBTC operation. These rolling stock include the R143s,{{cite book|url=https://books.google.com/books?id=6WFHNSXBpocC&pg=PA282|title=New York Subways: An Illustrated History of New York City's Transit Cars|author=Gene Sansone|date=October 25, 2004|publisher=JHU Press|isbn=978-0-8018-7922-7|pages=273–282|access-date=April 30, 2018}} R188s,{{cite web|url=http://web.mta.info/mta/news/books/pdf/121029_1400_CPOC.pdf#page=8|title=Capital Program Oversight Committee Meeting October 2012|date=October 29, 2012|publisher=Metropolitan Transportation Authority|archive-url=https://web.archive.org/web/20160205142707/http://web.mta.info/mta/news/books/pdf/121029_1400_CPOC.pdf|archive-date=February 5, 2016|url-status=dead|access-date=July 14, 2016}}{{Cite web|url = http://web.mta.info/mta/news/books/pdf/160125_1345_CPOC.pdf|title =Capital Program Oversight Committee Meeting January 2016|date = January 25, 2016|access-date = January 23, 2016|website = mta.info|publisher = Metropolitan Transportation Authority|url-status = dead|archive-url = https://web.archive.org/web/20160129071849/http://web.mta.info/mta/news/books/pdf/160125_1345_CPOC.pdf|archive-date = January 29, 2016|df = mdy-all}} and R160s.{{cite web|author1=Press Release|title=Mta Nyc Transit Awards New Car Contract|url=http://www.mta.info/press-release/mta-headquarters/mta-nyc-transit-awards-new-car-contract|publisher=Metropolitan Transportation Authority|access-date=July 14, 2016|archive-url=https://web.archive.org/web/20060203070803/http://www.mta.nyc.ny.us/mta/news/releases02/020731.htm|archive-date=February 3, 2006|url-status=live|date=July 31, 2002}}{{cite news|url=https://www.nytimes.com/2002/07/31/nyregion/1700-subway-cars-to-be-built-under-largest-such-contract-in-new-york-history.html|title=1,700 Subway Cars to Be Built Under Largest Such Contract in New York History|last1=Kennedy|first1=Randy|date=July 31, 2002|work=The New York Times|access-date=April 30, 2018|page=B3}} Initially, only 64 R160As (fleet numbers 8313–8376) were equipped with CBTC, but the remainder of the fleet was retrofitted with CBTC for Queens Boulevard automation.{{Cite web|url=http://web.mta.info/mta/news/books/pdf/170724_1345_CPOC.pdf|title=Capital Program Oversight Committee Meeting July 2017|date=July 24, 2017|publisher=Metropolitan Transportation Authority|page=18|access-date=October 28, 2017}} Future car orders are also designed to be CBTC-compatible, such as the R179. All R211s will have CBTC.{{Cite web|url=http://web.mta.info/mta/news/books/pdf/181022_1000_Transit.pdf|title=New York City Transit and Bus Committee Meeting October 2018|date=October 19, 2018|website=mta.info|publisher=Metropolitan Transportation Authority|pages=188–189|access-date=October 20, 2018|archive-date=October 20, 2018|archive-url=https://web.archive.org/web/20181020140605/http://web.mta.info/mta/news/books/pdf/181022_1000_Transit.pdf|url-status=dead}} After the retirement of the R68 and R68A cars, all revenue cars, except those on the G, J, M, and Z trains as well as the shuttles, will be equipped with CBTC.{{cite web|url=http://web.mta.info/mta/pdf/CP/NeedsAssessment.pdf |title=Twenty-Year Capital Needs Assessment |website=mta.info|publisher=Metropolitan Transportation Authority|date=August 2009|access-date=September 12, 2016}} The BMT Canarsie Line was the first line to implement the automated technology, using Siemens's Trainguard MT CBTC system.{{cite news| url = https://www.nytimes.com/2007/05/22/nyregion/22subway.html | title = For Less Crowding on L Train, Think 2010, Report Says | access-date = May 24, 2007 | first=William | last=Neuman | date = May 22, 2007 | newspaper = The New York Times|url-access=limited}}

{{Multiple image

|align=center

|direction=horizontal

|total_width=800

|image1=Manhattan bound R143 L train at New Lots.jpg

|caption1=The R143 is the first automated rolling stock in the New York City Subway.

|image2=Manhattan bound R160 L train at New Lots.jpg

|caption2=1,550 R160A cars like this one are automated, out of 1,662 total R160A/B cars, while the rest will be retrofitted with CBTC in the future. The R160 is the system's second automated rolling stock.

|image3=R188 7 train.jpg

|caption3=The R188 is the system's third automated rolling stock and second fully automated fleet.

}}

Most subway services cannot significantly increase their frequencies during rush hours, except for the {{NYCS|1}}, G, J/Z, L, and M trains (the L service already is automated with CBTC). Therefore, transit planners are viewing the installation of CBTC as a way to free up track capacity for more trains to run, and have shorter headways between trains. However, installing CBTC in the New York City Subway is harder than in other systems due to the subway's complexity. The MTA hopes to install {{Convert|16|miles|km}} of CBTC-equipped tracks per year, while the Regional Plan Association wants the MTA to install CBTC signals on {{Convert|21|miles|km}} of tracks per year.{{cite web|url=http://library.rpa.org/pdf/RPA-Moving-Forward.pdf|title=Moving Forward: Accelerating the Transition to Communications-Based Train Control for New York City's Subways|website=rpa.org|publisher=Regional Plan Association|date=May 2014|access-date=September 12, 2016|archive-date=March 4, 2016|archive-url=https://web.archive.org/web/20160304091527/http://library.rpa.org/pdf/RPA-Moving-Forward.pdf|url-status=dead}}{{Cite web|url=http://nextcity.org/daily/entry/new-york-advanced-signaling-subway|title=Advanced Signaling Makes the Most Out of Old Subways, But Can New York Handle It?|last=Smith|first=Stephen|date=May 2, 2014|website=nextcity.org|publisher=Next City|access-date=August 6, 2016}}

However, even without CBTC, the system is currently retrofitted to operate at frequencies of up to 60 trains per hour (tph) on the IND Queens Boulevard Line (30 tph on each of the local and express pairs of tracks made possible by the Jamaica–179th Street terminal, which has four sidings past the terminal for each set of tracks) and 33 tph on the IRT Flushing Line. The BMT Canarsie Line is limited to a 26 tph frequency due to the bumper blocks at both of its terminals and power constraints;{{Cite web|url=http://www.mta.info/press-release/nyc-transit/mta-seeks-federal-funds-increase-capacity-canarsie-l-line|title=MTA Seeks Federal Funds to Increase Capacity on Canarsie L Line|date=December 12, 2014|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=June 23, 2019|archive-date=November 28, 2022|archive-url=https://web.archive.org/web/20221128213633/https://www.mta.info/press-release/nyc-transit/mta-seeks-federal-funds-increase-capacity-canarsie-l-line|url-status=dead}} however, the IRT Lexington Avenue Line operates at frequencies of 27 tph without CBTC.{{Cite web|url=http://observer.com/2013/03/how-much-more-williamsburg-development-can-the-l-train-handle/|title=How Much More Williamsburg Development Can the L Train Handle?|date=March 5, 2013|website=The Observer|language=en-US|access-date=September 12, 2016}} By contrast, lines on the Moscow Metro can operate at frequencies of up to 40 tph, since lines in the Moscow Metro, unlike most of the New York City Subway (but like the Jamaica–179th Street station), typically have four sidings past the terminals instead of bumper blocks or one or two sidings.{{Cite book|url=https://books.google.com/books?id=NbYqQSQcE2MC|title=Rail Transit Capacity|last1=Parkinson|first1=Tom|last2=Fisher|first2=Ian|date=January 1, 1996|publisher=Transportation Research Board|isbn=9780309057189|pages=70|language=en|access-date=April 30, 2018}}

File:NYCS_Grand_Central_Shuttle.jpg was the first line in the New York City Subway to be automated, using Track 4 (shown on right).]]

The 42nd Street Shuttle, which runs from Grand Central to Times Square, was briefly automated from 1959 to 1964. The chairman of the Board of Transportation, Sidney H. Bingham, in 1954, first proposed a conveyor belt-like system for the shuttle line,{{Cite journal|date=May 1951|title=Endless Train to End New York Subway Jam|url=https://archive.org/details/bub_gb_hSEDAAAAMBAJ|journal=Popular Science|language=en|publisher=Bonnier Corporation|page=[https://archive.org/details/bub_gb_hSEDAAAAMBAJ/page/n102 101]|access-date=April 30, 2018}}{{cite magazine | title=TRANSPORTATION: Subway of the Future | magazine=Time | date=November 15, 1954 | url=http://content.time.com/time/magazine/article/0,9171,820451,00.html | access-date=January 17, 2017}} but the plan was canceled due to its high cost.{{Cite news|url=https://www.nytimes.com/1964/04/22/shuttle-is-short-except-in-history.html|title=Shuttle Is Short, Except in History|last=Stengren|first=Bernard|date=April 22, 1964|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}}{{cite web | last=Levey | first=Stanley | title=Times Sq. Shuttle Keeps Trains; Belt Plan Dropped as Too Costly; TIMES SQ. SHUTTLE WON'T GET A BELT | website=The New York Times | date=October 21, 1955 | url=https://www.nytimes.com/1955/10/21/archives/times-sq-shuttle-keeps-trains-belt-plan-dropped-as-too-costly-times.html | access-date=January 17, 2017|url-access=subscription}} Subsequently, in 1958, the newly formed New York City Transit Authority (NYCTA) started studying the feasibility of automatically operated trains which did not have motormen. The NYCTA conducted the study in conjunction with the General Railway Signal Company; the Union Switch and Signal division of the Westinghouse Air Brake Company; General Electric; and Western Electric. The next year, NYCTA president Charles Patterson made a speech about the results of the automated mass transit study. It was estimated that on the 42nd Street Shuttle alone, full automation could result in a $150,000 annual savings.{{cite web | last=Katz | first=Ralph | title=Crewless Subway Train Studied For Test on Times Sq. Shuttle; SUBWAY MAY TEST SELF-RUN TRAINS | website=The New York Times | date=January 27, 1959 | url=https://www.nytimes.com/1959/01/27/archives/crewless-subway-train-studied-for-test-on-times-sq-shuttle-subway.html | access-date=April 25, 2018|url-access=subscription}} By late 1961, the NYCTA was also considering automating the IRT Flushing Line, Culver Shuttle, and BMT Franklin Avenue Line if the 42nd Street Shuttle test were successful.{{Cite news|last=Levey|first=Stanley|date=October 25, 1961|title=Crewless Trains to Fair Studied; 3 Lines May Be Automated If Shuttle Test Succeeds|url=https://www.nytimes.com/1961/10/25/archives/crewless-trains-to-fair-studied-3-lines-may-be-automated-if-shuttle.html|access-date=May 24, 2024|work=The New York Times|language=en-US|issn=0362-4331|url-access=subscription}}

Starting in December 1959,{{Cite news|url=https://www.nytimes.com/1960/02/16/archives/crewless-subway-tested-in-brooklyn.html|title=Crewless Subway Tested in Brooklyn|date=February 16, 1960|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} the fully automatic train was tested on the BMT Sea Beach Line express tracks between the 18th Avenue and New Utrecht Avenue stations.{{Cite news|url=https://www.nytimes.com/1961/12/13/archives/disputed-automated-train-put-through-test-electrical-impulses-start.html|title=Disputed Automated Train Put Through Test; Electrical Impulses Start, Monitor and Stop Shuttle Runs AUTOMATED TRAIN PUT THROUGH TEST|last=Stengren|first=Bernard|date=December 13, 1961|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} The idea of automation at that time relied on commands that were sent to the train while the train is at a station, to keep its doors open. The train was equipped with a telephone system to keep voice communication with human dispatchers at the two shuttle terminals. At each station there was a cabinet that housed 24 relay systems that made up electronic dispatchers. The relays controlled the train's starting, acceleration, braking, and stopping, as well as the opening and closing of the car doors. When the commands cease, the doors would promptly close. A new series of commands would start the train and gradually accelerate it to {{convert|30|mph|km/h}}, its full speed, slowing to {{convert|5.5|mph}} when coming into the two stations. When entering stations, the train passed through a series of detectors, which caused a series of tripper arms at trackside to go into the open position if the train was going at the correct speed. If the train was going too quickly, the tripper arms would stay upright and the train's brakes would automatically be set.

The equipment was built and installed by General Railway Signal and Union Switch and Signal. The NYCTA contributed between $20,000 to $30,000 on the project and supplied the three R22 subway cars to be automated. The bulk of the money, between $250,000 and $300,000, was contributed by the two companies, which paid for installation, maintenance and technological oversight of the automation process, including signaling. The automation of the shuttle was opposed by the president of the Transport Workers Union, Michael J. Quill, who pledged to fight the project and called the device "insane."{{Cite news|url=https://www.nytimes.com/1960/10/14/archives/automatic-subway-train-tested-for-times-sq-shuttle-service.html|title=Automatic Subway Train Tested For Times Sq. Shuttle Service|last=Katz|first=Ralph|date=October 14, 1960|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}}

The R22s were fitted with different types of brake shoes, to see which one would negotiate the rail joints better. It was eventually found that the automated trip took 10 seconds longer than manual operation (about 95 seconds, compared to 85 seconds). As the tests on the Sea Beach Line progressed, grade time stops were added to ensure safety on the line, and on the 42nd Street Shuttle. The train was dubbed SAM, and was to operate on Track 4 of the shuttle line.

In the afternoon of January 4, 1962,{{Cite news|url=https://www.nytimes.com/1962/04/04/archives/automatic-shuttle-has-lost-novelty-for-new-yorkers.html|title=Automatic Shuttle Has Lost Novelty For New Yorkers|date=April 4, 1962|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} the three-car automated train began service, with a ceremony.{{Cite news|url=https://www.nytimes.com/1962/01/05/archives/first-automated-subway-train-starts-run-shuttle-riders-find-trip.html|title=First Automated Subway Train Starts Run; Shuttle Riders Find Trip Without Crew About the Same STRIKE ENDED ONE-YEAR PACT All 3 Will Benefit|last=Katz|first=Ralph|date=January 5, 1962|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} The trains carried a stand-by motorman during the six-month trial period. The train had scheduled to begin service on December 15, 1961, but Quill threatened a walkout at all of the city's municipal and privately-owned transit if the train ran.{{Cite news|url=https://www.nytimes.com/1961/12/11/archives/twu-will-hold-strike-vote-in-protest-of-automated-train.html|title=T.W.U. Will Hold Strike Vote In Protest of Automated Train|date=December 11, 1961|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} Under the new contract with the TWU, the NYCTA agreed to put a motorman in the train during the experimental period.{{Cite news|url=https://www.nytimes.com/1962/01/04/archives/shuttle-to-begin-automated-runs-public-tests-start-today-with.html|title=SHUTTLE TO BEGIN AUTOMATED RUNS; Public Tests Start Today With Stand-By Motorman Pledge on Manning|last=Katz|first=Ralph|date=January 4, 1962|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} While in its experimental period, the automated train was only operating during rush hours.{{Cite news|url=https://www.nytimes.com/1962/01/06/archives/a-better-shuttle.html|title=A Better Shuttle|date=January 6, 1962|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} In July, the test was extended for three more months, and in October the test was extended for six additional months.{{Cite news|url=https://www.nytimes.com/1962/10/28/archives/automated-train-given-extension-irts-shuttle-will-continue-running.html|title=AUTOMATED TRAIN GIVEN EXTENSION; IRT's Shuttle Will Continue Running Until July 1|date=October 28, 1962|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} The chairman of the NYCTA, Charles Patterson, was disappointed by the automated shuttle train, doubting that the train could be operated without any transit personnel on board.

Initially, the automation of the shuttle was expected to save $150,000 a year in labor costs; however, with one employee still required on the train, there would essentially be no savings.{{Cite news|url=https://www.nytimes.com/1962/09/19/archives/automated-train-disappoints-city-patterson-says-high-hopes-for.html|title=AUTOMATED TRAIN DISAPPOINTS CITY; Patterson Says High Hopes for Subway Device Have Been Diminished RESEARCH IS EXTENDED IRT Shuttle to Be Tested for Nine Months More-- Some Savings Seen|last=Stengren|first=Bernard|date=September 19, 1962|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} If the test succeeded, it was planned to automate the IRT Flushing Line, the BMT Canarsie Line, the BMT Myrtle Avenue Line, the Franklin Avenue Shuttle, and the Culver Shuttle. These lines were chosen because the train services on all five lines, as well as the 42nd Street Shuttle, did not regularly share tracks with any other services. At the time, the NYCTA did not have plans to automate the whole system. The rest of the system included a myriad of instances where several different services merged and shared tracks, and automating the rest of the system would have been logistically difficult. The Canarsie and Myrtle Avenue Lines were later cut from the plans, but it was expected that the other three lines would be automated if the test was successful.{{Cite news|url=https://www.nytimes.com/1961/10/25/archives/crewless-trains-to-fair-studied-3-lines-may-be-automated-if-shuttle.html|title=CREWLESS TRAINS TO FAIR STUDIED; 3 Lines May Be Automated If Shuttle Test Succeeds|last=Levey|first=Stanley|date=October 25, 1961|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}}

A severe fire at the Grand Central station on April 21, 1964, destroyed the demonstration train.{{cite web|url=http://chicagotribune.newspapers.com/search/#lnd=1&ymd=1964-04-22&query=Subway+Fire+Jams+N.+Y.+Traffic+%28%29&t=4351&oquery=Subway+Fire+Jams+N.+Y.+Traffic+%28April+22%2C+1964%29|title=Subway Fire Jams N. Y. Traffic (April 22, 1964)|date=April 22, 1964|website=Chicago Tribune|url-access=subscription|access-date=January 17, 2017}} The fire began under a shuttle train on track 3, and it became larger, feeding on the wooden platform. The train on Track 1 was saved when the motorman saw smoke, and reversed the train. The basements of nearby buildings were damaged. Tracks 1 and 4 returned to service on April 23, 1964,{{Cite news|url=https://www.nytimes.com/1964/04/24/shuttle-nearly-back-to-normal.html|title=Shuttle Nearly Back to Normal|last=Trumbull|first=Robert|date=April 24, 1964|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} while Track 3 returned to service on June 1, 1964.{{Cite book|url=https://books.google.com/books?id=Fg4KAQAAMAAJ&q=Bronx|title=A History of the New York City Subway System|last1=Cunningham|first1=Joseph|last2=DeHart|first2=Leonard O.|date=January 1, 1993|publisher=J. Schmidt, R. Giglio, and K. Lang|language=en|access-date=April 30, 2018}}{{Rp|83}} The reinstallation of Track 3 was delayed because of the need to replace 60 beams that were damaged in the fire.{{Cite news|url=https://www.nytimes.com/1964/04/25/reopening-put-off-on-one-42d-st-block.html|title=Reopening Put off on One 42d St. Block|date=April 25, 1964|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}} Reconstruction of the line continued through 1967.{{Cite news|url=https://query.nytimes.com/gst/abstract.html?res=9E0DE2D9133DE23BA1575AC0A9669D946791D6CF&legacy=true|title=Reconstruction Cuts Shuttle Service in Subway; 8-Month Project Curtailing Daily Travel of 24,400-- Job Will Cost $419,000|date=October 9, 1966|newspaper=The New York Times|access-date=January 15, 2017|issn=0362-4331|url-access=subscription}}

In 1978, senior NYCTA executive John de Roos said that the authority would consider running automated trains following the completion of the 63rd Street lines, which were then scheduled to be opened in 1984 or 1985.{{Cite news |date=April 16, 1978 |title=Follow-Up On the News |language=en-US |work=The New York Times |url=https://www.nytimes.com/1978/04/16/archives/followup-on-the-news-automated-subway-gum-slander-train-mystery.html |access-date=April 12, 2022 |issn=0362-4331}}

Automated rapid transit technology was later installed in the San Francisco Bay Area's BART system and the Philadelphia metropolitan area's PATCO Speedline.{{cite book|url=https://www.princeton.edu/~ota/disk3/1976/7614/761408.PDF|title=Automatic Train Control in Rail Rapid Transit|author=United States Congress, Office of Technology Assessment|date=May 1976|publisher=Princeton University|page=135|chapter=Chapter 6: THE PLANNING AND DEVELOPMENT PROCESS|access-date=April 25, 2018}} After the fire that destroyed the automated shuttle subway cars, ideas for New York City Subway automation lay dormant for years, until an intoxicated motorman caused a train crash at Union Square station that killed 5 people and injured 215. The collision was a catalyst to a 1994 business case outlining arguments for automatic train operation (ATO) and CBTC, which led to the automation of the BMT Canarsie Line starting in the early 2000s.{{cite web|url=https://www.nytimes.com/1991/09/01/nyregion/catastrophe-under-union-square-crash-lexington-irt-motorman-s-run-disaster.html|title=Catastrophe Under Union Square; Crash on the Lexington IRT: Motorman's Run to Disaster|last=McFadden|first= Robert D.|date=September 1, 1991|work=The New York Times|access-date=June 11, 2014|url-access=limited}} In 1997, the year the Canarsie Line project started, the whole subway was to be automated by 2017, but by 2005, the completion date had been pushed back to 2045.

The first two lines, totaling {{Convert|50|mi|km}} of track miles, received CBTC from 2000 to 2018. The two lines with the initial installations of CBTC were both chosen because their respective tracks are relatively isolated from the rest of the subway system, and they have fewer junctions along the route.

The Canarsie Line, on which the L service runs, was chosen for CBTC pilot testing because it is a self-contained line that does not operate in conjunction with other subway lines in the New York City subway system. The 10-mile length of the Canarsie Line is also shorter than the majority of other subway lines. As a result, the signaling requirements and complexity of implementing CBTC are easier to install and test than the more complicated subway lines that have junctions and share trackage with other lines. Siemens Transportation Systems built the CBTC system on the Canarsie Line.{{cite web | title=Canarsie CBTC goes live | website=Railway Gazette | date=March 12, 2009 | url=http://www.railwaygazette.com/news/single-view/view/canarsie-cbtc-goes-live.html | access-date=January 18, 2017 | archive-date=January 7, 2017 | archive-url=https://web.archive.org/web/20170107005458/http://www.railwaygazette.com/news/single-view/view/canarsie-cbtc-goes-live.html | url-status=dead }}

The CBTC project was first proposed in 1994 and approved by the MTA in 1997. Installation of the signal system was begun in 2000. Initial testing began in 2004, and installation was mostly completed by December 2006, with all CBTC-equipped R143 subway cars in service by that date. Due to an unexpected ridership increase on the Canarsie Line, the MTA ordered more R160 cars and these were put into service in 2010. This enabled the agency to operate up to 20 trains per hour up from the May 2007 service level of 15 trains per hour, an achievement that would not be possible without the CBTC technology or a redesign of the previous automatic block signal system. The R143s and R160s both use Trainguard MT CBTC, supplied by Siemens.{{Cite news|url=http://www.railwayage.com/index.php/communications/siemens-lands-nyct-qbl-phase-1-cbtc-contract.html|title=Siemens, Thales Land NYCT QBL West Phase 1 CBTC Contracts|last=Vantuono|first=William C.|date=August 27, 2015|work=Railway Age|language=en-gb|access-date=January 31, 2017|archive-date=February 20, 2017|archive-url=https://web.archive.org/web/20170220030407/http://www.railwayage.com/index.php/communications/siemens-lands-nyct-qbl-phase-1-cbtc-contract.html|url-status=dead}} In the 2015–2019 Capital Program, funding was provided for three more electrical substations for the line so service could be increased from 20 to 22 trains per hour. Also included in the Capital Program is the installation of automatic signals on the line to facilitate the movement of work trains between interlockings.{{Cite web|url=http://web.mta.info/capitaldashboard/CPDHome.html|title=Capital Program Dashboard|website=web.mta.info|publisher=Metropolitan Transportation Authority|access-date=January 13, 2017}}

File:111th St IRT td (2019-08-07) 12a.jpg subway cars constructed for the Flushing Line have CBTC.]]

The next line to have CBTC installed was the pre-existing IRT Flushing Line and its western extension opened in 2015 (served by the {{NYCS trains|Flushing}}). The Flushing Line was chosen for the second implementation of CBTC because it is also a self-contained line with no direct connections to other subway lines currently in use, aside from the merging of express and local services. The 2010–2014 MTA Capital Program provided funding for CBTC installation on the Flushing Line, with scheduled installation completion in 2016.{{cite web|url=http://web.mta.info/mta/pdf/2010-14questions_and_answers_v2.pdf#page=11 |title=MTA 2010–2014 Capital Program Questions and Answers |pages=11–12 |website=mta.info|publisher=Metropolitan Transportation Authority |access-date=September 12, 2016}} The R188 cars were ordered in 2010 to equip the line with compatible rolling stock.{{cite web|url=http://www.kawasakirailcar.com/page-24|title=R188 Acceptance|date=January 2014|website=Kawasaki Rail Car, Inc.|access-date=September 13, 2016|archive-date=September 19, 2016|archive-url=https://web.archive.org/web/20160919040018/http://www.kawasakirailcar.com/page-24|url-status=dead}} This order consists of new cars and retrofits of existing R142A cars for CBTC.{{Cite web|url=http://web.mta.info/mta/news/books/docs/2012-10_CPOC_Railcar_Presentation_11_26_12_a.ppt|title=NYCT Subway Car Program Progress Update to CPOC |first=Michael P.|last=Wetherell|website=mta.info|publisher=Metropolitan Transportation Authority|date=November 26, 2012 | access-date=September 13, 2016}}

In late winter 2008, the MTA embarked on a 5-week renovation and upgrade project on the {{NYCS trains|Flushing}} between Flushing–Main Street and 61st Street–Woodside to upgrade signaling and tracks for CBTC. On February 27, 2008, the MTA issued an Accelerated Capital Program to continue funding the completion of CBTC for the {{NYCS trains|Flushing|time=nolink}} and to begin on the IND Queens Boulevard Line ({{NYCS trains|Queens express}}). The installation is being done by Thales Group,{{cite web|url=https://www.thalesgroup.com/en/worldwide/transportation/press-release/thales-selected-new-york-metropolitan-transportation|title=Thales Selected by the New York Metropolitan Transportation Authority to Modernize the Queens Boulevard Line|date=January 10, 2015|website=Thales Group|access-date=September 13, 2016}} which was awarded the contract for the project on June 16, 2010.{{Rp|10}} CBTC, as well as the new track configuration added in the line's 2015 extension, allowed the {{NYCS trains|Flushing|type=service}} to run 2 more tph during peak hours, increasing service from 27 to 29 tph.{{Cite web|url=http://web.mta.info/mta/news/books/pdf/190624_1430_CPOC.pdf|title=Capital Program Oversight Committee Meeting June 2019|date=June 2019|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=June 23, 2019}}{{Rp|24, 40}}

File:A CBTC transponder at Mets–Willets Point station.jpg. CBTC-equipped trains use such fixed transponders to locate themselves.]]

The first train of R188 cars began operating in passenger service on November 9, 2013.{{cite news|url=https://blogs.wsj.com/metropolis/2013/11/18/mta-tests-new-subway-trains-on-flushing-line/|title=MTA Tests New Subway Trains on Flushing Line|last=Mann|first=Ted|date=November 18, 2013|newspaper=The Wall Street Journal|access-date=November 19, 2013}} Test runs of R188s in automated mode started in late 2014.{{cite web|url=http://www.mta.info/news/2013/11/18/new-subway-cars-being-put-test|title=New Subway Cars Being Put to the Test|date=November 18, 2013|work=mta.info|publisher=Metropolitan Transportation Authority|access-date=April 29, 2018|archive-date=May 15, 2014|archive-url=https://web.archive.org/web/20140515152907/http://www.mta.info/news/2013/11/18/new-subway-cars-being-put-test|url-status=dead}} However, the CBTC retrofit date was later pushed back to 2017{{Cite news|url=http://www.amny.com/transit/7-train-signal-upgrade-still-expected-to-be-completed-in-2017-mta-says-1.14080694|title=7 Train Signal Upgrade on Track for 2017: MTA|last=Barone|first=Vincent|date=August 21, 2017|work=am New York|access-date=August 23, 2017|language=en}} and then to 2018 after a series of problems that workers encountered during installation, including problems with the R188s. The project also went over budget, costing $405 million for a plan originally marked at $265.6 million. In February 2017, the MTA started overnight testing of CBTC on the Flushing Line from Main Street to 74th Street, with CBTC being used in regular passenger service by August and full implementation in October. By February 2018, the rest of the line from 74th Street to 34th Street–Hudson Yards was projected to begin operating in CBTC service in fall 2018. CBTC was activated on the segment between 74th Street and the Steinway Tunnel over eight weekends in mid-2018. The remaining segment of the Flushing Line, between the Steinway Tunnel and 34th Street–Hudson Yards, began operating in CBTC service on November 26, 2018.{{Cite web|url=http://web.mta.info/mta/news/books/pdf/181113_1400_CPOC.pdf|title=Capital Program Oversight Committee Meeting November 2018|date=November 13, 2018|access-date=April 20, 2018|publisher=Metropolitan Transportation Authority}}{{rp|11–12}} However, the MTA also stated that several more weeks of maintenance work would be needed before the system was fully operational.{{cite web | last=Nessen | first=Stephen | title=New Signals Fully Installed On 7 Line, But When Will Riders See Improvements? | website=Gothamist | date=November 27, 2018 | url=http://gothamist.com/2018/11/27/7_line_signal_changes_delays.php | access-date=February 21, 2019 | archive-date=April 11, 2019 | archive-url=https://web.archive.org/web/20190411161709/http://gothamist.com/2018/11/27/7_line_signal_changes_delays.php | url-status=dead }} The project was substantially completed on March 7, 2019, and full automatic train operation began in May 2019, allowing for the increase in service to 29 tph. The MTA's Independent Engineering Consultant noted that CBTC can support the operation of additional service, and recommended that NYCT use a simulation of the line to identify line constraints and bottlenecks, and undertake projects to increase the capacity of the line.{{Rp|40}}

[[File:NYCS_map_CBTC_enabled.svg|thumb|300px|Map of lines where CBTC is being installed or where CBTC is active {{as of|lc=y|December 2024}}:

{{bulleted list|{{Color box|#f00}} CBTC active|{{Color box|#00f}} CBTC installation in progress}}

|alt=Map of New York City Subway lines where CBTC is being installed or where CBTC is active

]]

As part of the 2015–2019 Capital Program, there will be {{Convert|73.2|mi|km}} of lines that will get CBTC, at a cost of $2.152 billion (part of a $2.766 billion automation/signaling project that is being funded in the Capital Program). Another $337 million is to be spent on extra power substations for CBTC. This installation of CBTC would require Siemens and Thales to cooperate on the installation process for all of the lines; they had worked separately in installing the Canarsie Line's and Flushing Line's CBTC systems, respectively.

Funding was allocated for the installation of CBTC equipment on one of the IND Culver Line express tracks between Fourth Avenue and Church Avenue. The total cost was $99.6 million, with $15 million coming from the 2005–2009 capital budget and $84.6 million from the 2010–2014 capital budget. The installation was a joint venture between Siemens and Thales Group.{{cite web|url=http://www.alamys.org/media/61869/26_metrorail.pdf|title=CBTC Interoperability: From Real Needs to Real Deployments – New York's Culver CBTC Test Track Project|last2=Yelloz|first2=Gerard|date=March 28, 2012|website=alamys.org|publisher=Metrorail, London|archive-url=https://web.archive.org/web/20151126173620/http://www.alamys.org/media/61869/26_metrorail.pdf|archive-date=November 26, 2015|url-status=dead|access-date=September 12, 2016|first1=Gabriel|last1=Colceag}} The test track project was completed in December 2015.{{Cite web|url=http://web.mta.info/mta/news/books/archive/160725_1345_CPOC.pdf|title=Capital Program Oversight Committee Meeting July 2016|date=July 25, 2016|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=April 29, 2018}}{{Rp|28}} This installation was intended to be permanent. Had Culver Line express service been implemented at the time, it would not have used CBTC, and testing of CBTC on the express track would have been limited to off-peak hours. Test trains on the track were able to successfully operate using the interoperable Siemens/Thales CBTC system. That system became the standard for all future CBTC installations on New York City Transit tracks {{As of|2015|lc=yes}}. A third supplier, Mitsubishi Electric Power Products Inc., was given permission to demonstrate that its technology could be interoperable with the Siemens/Thales technology. The $1.2 million Mitsubishi contract was approved in July 2015.

As part of the 2015–2019 Capital Program, the section of the line between Church Avenue and West Eighth Street–New York Aquarium would receive CBTC. Three interlockings between Church Avenue and West Eighth Street—at Ditmas Avenue, Kings Highway, and Avenue X—would be upgraded. A contract for CBTC overlay, as well as modernization of the Ditmas Avenue and Avenue X interlockings, was awarded in February 2019,{{Rp|20}} with substantial completion expected in June 2023.{{rp|10}} Tutor Perini was the primary contractor and installer.{{Rp|7}} The timeline was delayed because of difficulties in installing new longer-lasting ties on the tracks.{{Cite web |date=April 25, 2022 |title=Capital Program Committee Meeting April 2022 |url=https://new.mta.info/document/85841 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority}}{{rp||page=16}}

File:Queens Plaza by David Shankbone.jpg (pictured here at Queens Plaza).]]

In the 2010s, the MTA implemented CBTC on the western portion of the IND Queens Boulevard Line (QBL West). CBTC was to be installed on this line in five phases, with phase one (50th Street/8th Avenue and 47th–50th Streets–Rockefeller Center to Kew Gardens–Union Turnpike) being included in the 2010–2014 capital budget. The 63rd Street Connection to 21st Street–Queensbridge would also be retrofitted with CBTC.{{Cite web|url=http://web.mta.info/mta/news/books/pdf/170724_1345_CPOC.pdf|title=Capital Program Oversight Committee Meeting July 2017|date=July 24, 2017|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=September 15, 2017}}{{Rp|16}} The total cost for eventually automating the entire Queens Boulevard Line is estimated at over $900 million, The automation of the Queens Boulevard Line means that the {{NYCS trains|Queens express|type=service}} will be able to run 3 more trains during peak hours (it currently runs 29 tph). This will also increase capacity on the local tracks of the IND Queens Boulevard Line. However, as the line hosts several services, installation of CBTC on the line can be much harder than on the Flushing and Canarsie lines.

On December 15, 2014, a contract to provide consulting services to support the installation of CBTC was awarded to Systra Engineering.{{Cite web|date=June 2019|title=New York City Transit and Bus Committee Meeting June 2019|url=http://web.mta.info/mta/news/books/pdf/190624_1030_Transit.pdf|access-date=June 23, 2019|website=mta.info|publisher=Metropolitan Transportation Authority|pages=192–193}} Following the success of the Culver Line CBTC test track, the MTA awarded a $205.8 million contract for the installment of phase one to Siemens on August 24, 2015, and Thales on August 31, 2015.{{Rp|14}} These two suppliers were the only MTA-qualified suppliers that could install CBTC on New York City Transit tracks. Seven of eight interlockings in the first-phase section of the line would be upgraded under this contract. In conjunction with the project, 309 four- or five-car sets of R160s will receive Trainguard MT CBTC, the same CBTC system installed on trains assigned to the BMT Canarsie Line, which will be compatible with the SelTrac CBTC system installed on the tracks. Of the 309 units set to be converted for CBTC-compatibility, 305 will receive new onboard equipment, which NYCT contractors will install in 301 of these 305 units.{{efn|There are 16 four-car sets that were equipped with CBTC as part of the Canarsie Line automation project, out of 351 four- and five-car sets total. The Queens Boulevard Line CBTC contract will bring the number of CBTC-equipped R160 sets to 325 out of 351 total sets.}} {{As of|June 2019||df=}}, 155 units had been retrofitted.{{Rp|14}} {{As of|April 2022}}, the number of R160 sets with CBTC had been increased to 335, of which 310 units were already equipped.{{rp||page=15}}

Planning for phase one started in 2015 and was complete by February 2016, with major engineering work following in November 2016.{{Cite web|url=http://www.mta.info/news-cbtc-new-york-city-transit-subway-l-7/2015/07/20/2058m-contracts-approved-install|title=$205.8M in Contracts Approved to Install Communications-Based Train Control System|date=July 20, 2015|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=August 6, 2016|archive-date=July 28, 2016|archive-url=https://web.archive.org/web/20160728222048/http://www.mta.info/news-cbtc-new-york-city-transit-subway-l-7/2015/07/20/2058m-contracts-approved-install|url-status=dead}}{{Cite web|url=http://web.mta.info/capitaldashboard/allframenew_head.html?PROJNUM=t7080301&PLTYPE=9|title=Install Communication-Based Train Control on the Queens Boulevard Line West – Phase 2|website=web.mta.info|publisher=Metropolitan Transportation Authority|access-date=April 29, 2018}} On December 22, 2016, as part of the second phase of CBTC installation on the Queens Boulevard Line, L.K. Comstock & Company Inc. was awarded the $223.3-million contract to upgrade existing signals and install communications, fiber-optic, and CBTC infrastructure for the new signal system.{{Cite news|url=http://www.rtands.com/index.php/cs/mta-awards-lk-comstock-with-queens-boulevard-line-signaling-contract.html?channel=|title=MTA Awards L.K. Comstock Queens Boulevard Line Signaling Contract|last=Wanek-Libman|first=Mischa|date=January 5, 2017|language=en-gb|access-date=January 31, 2017}} The core of phase one was originally supposed to be completed by 2020 or 2021.{{Rp|18}} However, by April 2018, the MTA projected that most of the infrastructure from 50th Street to Union Turnpike would be substantially completed by mid-2022.{{Cite web|url=http://web.mta.info/mta/news/books/pdf/180423_1330_CPOC.pdf|title=Capital Program Oversight Committee Meeting April 2018|date=April 23, 2018|access-date=April 20, 2018|publisher=Metropolitan Transportation Authority}}{{rp|59–65}} The testing of the integrated Siemens/Thales system began in August 2018 and was completed by May 2019, followed by the start of train-operator training simulations in June 2019.{{rp|15}} {{As of|November 2018}}, phase one was to be substantially completed by March 2021, followed by phase two in July 2022.{{rp|15, 18}} On March 26, 2019, Systra's contract to provide consulting services was extended by 23 months to support the extension of CBTC from Union Turnpike to 179th Street on the Queens Boulevard Line and to Jamaica Center on the IND Archer Avenue Line (QBL East). {{As of|November 2020|alt=By November 2020}}, various difficulties and delays had pushed back the substantial completion date to the third or fourth quarter of 2021.{{Cite web|url=https://new.mta.info/document/23941|title=Capital Program Oversight Committee Meeting November 2020|date=November 18, 2020|access-date=April 20, 2018|publisher=Metropolitan Transportation Authority}}{{rp|6}} A consultant for the MTA predicted that the CBTC system could not be activated as planned in March 2021 because of a lack of immediate funding and a shortage of CBTC-equipped trains.{{Rp|11–13}} The forecast was then pushed back to the fourth quarter of 2021.{{Cite web|url=https://new.mta.info/document/64066|title=Capital Program Oversight Committee Meeting November 2021|date=November 15, 2021|access-date=April 20, 2018|publisher=Metropolitan Transportation Authority}}{{rp|6}} The final section was activated in February 2022.{{rp||page=15}} ATO operation commenced in early March 2024.{{cite web|url=https://new.mta.info/document/135341|title=Capital Program Committee Meeting March 2024|publisher=MTA|accessdate=March 23, 2024|page=28}}

The 2015–2019 Capital Program was revised in April 2018 to fund to the design for the expedited installation of CBTC on the Lexington Avenue Line, the IND Archer Avenue Line and the Queens Boulevard Line east of Kew Gardens–Union Turnpike, known as QBL East.{{Cite web |date=November 16, 2018 |title=T7080341 Install Communication-Based Train Control (CBTC): Lexington Ave Line and Interlockings |url=http://web.mta.info/capitaldashboard/allframenew_pi.php?PROJNUM=t7080341&PLTYPE=1 |access-date=November 26, 2018 |website=web.mta.info |publisher=Metropolitan Transportation Authority}}{{Cite web |date=November 16, 2018 |title=T7080340 Install Communication-Based Train Control (CBTC): Queens Blvd East and Interlockings |url=http://web.mta.info/capitaldashboard/allframenew_pi.php?PROJNUM=t7080340&PLTYPE=1 |access-date=November 26, 2018 |website=web.mta.info |publisher=Metropolitan Transportation Authority}} The draft 2020–2024 Capital Program calls for CBTC installation on the remainder of the IND Queens Boulevard Line to Jamaica–179th Street station, as well as the IND Archer Avenue Line.{{cite web |last=Guse |first=Clayton |date=September 16, 2019 |title=MTA Announces $51 Billion Plan to Save the Subway, Treat NYC's Transit Sickness |url=https://www.nydailynews.com/new-york/ny-capital-plan-five-year-51-billion-20190916-vv4redne5nfkvjrjtfwxuuckqi-story.html |access-date=September 16, 2019 |website=New York Daily News}}{{Cite web |date=September 2019 |title=MTA Capital Program 2020–2024 |url=https://new.mta.info/document/10511#page=67 |access-date=March 30, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority}} On December 15, 2021, the MTA Board approved the first of three contracts to install CBTC on the eastern portion of the Queens Boulevard Line.{{Cite web |date=December 15, 2021 |title=MTA Announces Extension of Signal Modernization on the Queens Boulevard Line |url=https://new.mta.info/press-release/mta-announces-extension-of-signal-modernization-queens-boulevard-line |access-date=December 16, 2021 |website=mta.info |publisher=Metropolitan Transportation Authority |language=en}} Under the project, interlockings at Briarwood, Parsons Boulevard, 169th Street, and 179th Street would be modernized. The 169th Street interlocking would be separated from the 179th Street interlocking. In addition, the north end of Union Turnpike Interlocking will receive CBTC functionality. Following the Eighth Avenue Line CBTC project, track circuits will be replaced with axle counters. EJ Electric is the installer and Mitsubishi is the CBTC supplier. The cost of the project will be $539.5 million, and completion is forecasted for the second quarter of 2026. In December 2021, the contract for the installation of the project was awarded to EJ Electric while the contract for the supplying of CBTC equipment was awarded to Mitsubishi. In April 2022, the MTA was still negotiating with Siemens for the data communications system equipment contract. This will be Mitsubishi's first CBTC contract with the MTA, expanding the interoperability demonstration to three suppliers from two.{{rp||page=18}}

Funding for the design of CBTC on the IND Eighth Avenue Line from 59th Street–Columbus Circle to High Street is provided in the 2015–2019 Capital Program, along with the modernization of interlockings at 30th Street and north of 42nd Street, and the removal of an unused interlocking south of 42nd Street. The design of the Eighth Avenue Line CBTC project will be done concurrently with the Queens Boulevard Line West and East automation, allowing the E route to be semi-automated when the project is done. It will get two new electrical substations to support CBTC upgrades.{{cite web|title=MTA Capital Program 2015–2019: Renew. Enhance. Expand.|url=http://web.mta.info/capital/pdf/CapitalProgram2015-19_WEB%20v4%20FINAL_small.pdf|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=September 12, 2015|date=October 28, 2015}} Additionally, the R179 and R211 fleets will be made compatible with CBTC.{{rp|8}} Construction was originally scheduled to begin in October 2018, but a contract for CBTC installation was later pushed back to the first quarter of 2019.{{rp|28}} In March 2019, in preparation for the implementation of CBTC on the Eighth Avenue Line, the MTA board ratified a contract with Thales Group for the installation of CBTC equipment on the R211 fleet.{{Cite web|url=https://new.mta.info/document/124291|title=Capital Program Oversight Committee Meeting October 2023|date=Oct 2023|website=web.mta.info|publisher=Metropolitan Transportation Authority|access-date=January 19, 2018}}{{rp|page=47}}

On January 13, 2020, the MTA announced that it had awarded the contract to L. K. Comstock & Company, Inc. for $245.8 million. The signaling for the contract will be provided by Siemens. This will be the first CBTC project in the system to use axle-counters instead of insulated joints and track circuits.{{Cite web|url=http://www.mta.info/press-release/nyc-transit/mta-moves-forward-signal-modernization-eighth-avenue-ace-line|title=MTA Moves Forward with Signal Modernization of Eighth Avenue ACE Line|website=mta.info|publisher=Metropolitan Transportation Authority|access-date=January 13, 2020|archive-date=March 2, 2021|archive-url=https://web.archive.org/web/20210302204206/http://www.mta.info/press-release/nyc-transit/mta-moves-forward-signal-modernization-eighth-avenue-ace-line|url-status=dead}}{{Cite web |date=November 2020 |title=Capital Program Oversight Committee Meeting November 2020 |url=https://new.mta.info/document/23941 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority |page=8}} Axle counters are more resilient to debris and water, making them more reliable,{{Cite web |date=June 4, 2021 |title=MTA Announces Track Renewal and Signal Modernization Work Taking Place in Manhattan This Summer |url=https://new.mta.info/press-release/mta-announces-track-renewal-and-signal-modernization-work-taking-place-manhattan |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority |language=en}} and have been used for decades in systems around the world,{{Cite news |last=Guse |first=Clayton |date=January 13, 2020 |title=MTA to Bring Modern Signal System — and Faster, More Reliable Commutes — to Entirety of E Line by 2025 |work=New York Daily News |url=https://www.nydailynews.com/new-york/ny-subway-signals-cbtc-eighth-ave-line-mta-20200113-vlo2l24bibfypdkridikpetyki-story.html |access-date=July 14, 2022}} and will reduce the time it takes to complete CBTC projects, the cost of completing work,{{Cite web |date=April 2021 |title=Capital Program Oversight Committee Meeting April 2021 |url=https://new.mta.info/document/37061 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority |page=10}} and maintenance and life-cycle costs. Axle counters also allow CBTC testing before cutovers, reducing the time it takes to complete cutovers and any risks associated with them.{{Rp|page=13}} {{As of|November 2020|}}, the entire project is budgeted at $733.6 million.{{Rp|20}} The project will be completed by January 2025.{{Cite news|url=https://www.nydailynews.com/new-york/ny-subway-signals-cbtc-eighth-ave-line-mta-20200113-vlo2l24bibfypdkridikpetyki-story.html|title=MTA to Bring Modern Signal System — and Faster, More Reliable Commutes — to Entirety of E Line by 2025|last=Guse|first=Clayton|date=January 13, 2020|work=New York Daily News|access-date=January 13, 2020}}{{rp|8}} Work was 57 percent complete in April 2022. Due to delays in the completion of the R211 rolling stock contract, an alternative cutover plan was developed to allow CBTC on the local tracks to be placed into use before the express tracks.{{Rp|page=22}}

The MTA planned to put the contract to install CBTC on the Crosstown Line to Hoyt–Schermerhorn Streets station and modify the three interlockings on the line up for bid in 2022. The cost of the project is estimated to be $556.4 million.{{Cite web |date=February 18, 2022 |title=MTA 2022 Adopted Budget February Financial Plan 2022 – 2025 February 2022 |url=https://new.mta.info/document/76706#page=91 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority |page=V-3}} On May 16, 2022, the MTA put out the RFP for the design-build contract to install CBTC on the Crosstown Line. Court Square Interlocking will be modified to interface with CBTC while mechanical interlockings at Bedford–Nostrand Avenues and Nassau Avenue will be replaced. Relay rooms and towers at Bedford–Nostrand Avenues and Nassau Avenue will be decommissioned as part of the project. Following the Eighth Avenue and QBL East projects, this project will include the use of axle counters instead of track circuits. Work on the project is expected to take four years.{{Cite web |date=May 16, 2022 |title=Solicitation Title: S48012 Design-Build Services for Communication Based Train Control Crosstown Line "B" Division in Brooklyn and Queens |url=https://new.mta.info/document/87291 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority}} In December 2022, the MTA announced that it would award a $368 million design–build contract to Crosstown Partners, a joint venture between Thales Group and TC Electric LLC.{{cite web | last=Brachfeld | first=Ben | title=MTA set to award $368 million contract to modernize G line signals | website=amNewYork | date=December 20, 2022 | url=https://www.amny.com/transit/mta-contract-modernize-g-line-signals/ | access-date=December 21, 2022}}{{Cite web |date=December 19, 2022 |title=Capital Program Oversight Committee Meeting December 2022 |url=https://new.mta.info/document/102776|access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority |pages=99–101}} The contract includes not only the Crosstown Line between Court Square and Bergen Street, but also the Culver Line between Bergen Street and Church Avenue.

Unlike previous CBTC projects in the system, the Crosstown Line CBTC project will take a "CBTC-centric" approach, in which existing wayside interlockings as well as AWS systems will be replaced with new software logics in enhanced, centralized CBTC Zone Controllers – known as integrated Zone Controllers (iZCs). This will minimize wayside and room signaling equipments, reducing future maintenance burden. Also, the train-to-wayside communication will be based on 5G technology.{{cite web|url=https://new.mta.info/document/135341|title=Capital Program Committee Meeting March 2024|publisher=MTA|accessdate=March 23, 2024|page=44}}

On November 9, 2022, the MTA put out the RFP for the design-build contract to install CBTC on the Fulton Street Line between High Street and Euclid Avenue, on the Sixth Avenue Line from York Street to Jay Street–MetroTech, the Culver Line from Jay Street to both the upper and lower levels of Bergen Street, and on the Crosstown Line from Hoyt–Schermerhorn Streets to Bergen Street. This project will also use axle counters, and is expected to take six years.{{Cite web |date=November 9, 2022 |title=Solicitation Title: S48019 Design-Build Services for Communication Based Train Control Fulton Line in Brooklyn |url=https://new.mta.info/document/99396 |access-date=November 9, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority}} CBTC installation on the rest of the Fulton Street Line from Euclid Avenue to Ozone Park–Lefferts Boulevard was proposed as part of the MTA's 2025–2029 Capital Program.{{cite web |last=Andres |first=Czarinna |date=September 18, 2024 |title=MTA Unveils $68.4 Billion Capital Plan to Modernize NYC Transit – but Funding Questions Amid Congestion Pricing Pause Remain |url=https://www.amny.com/news/mta-revised-capital-plan-2024-congestion-pricing/ |access-date=September 19, 2024 |website=amNewYork}}{{cite web |last=Burkett |first=N.J. |date=September 18, 2024 |title=MTA Proposes Five-Year Capital Plan Wish List Including Replacing All Subway Cars |url=https://abc7ny.com/post/mta-proposes-year-capital-plan-wish-list-including-replacing-subway-cars/15321669/ |access-date=September 19, 2024 |website=ABC7 New York}}

In a 2014 report, the MTA projected that 355 miles of track would receive CBTC signals by 2029, including most of the IND, as well as the IRT Lexington Avenue Line and the BMT Broadway Line. The MTA was also planning to install CBTC equipment on the IND Crosstown Line, the BMT Fourth Avenue Line and the BMT Brighton Line before 2025.{{Cite report |title=Chapter 2: Project Alternatives |year=2004 |work=Second Avenue Subway FEIS |volume=I |pages=4 |url=https://www.mta.info/document/22101#page=4 |access-date=September 12, 2015 |publisher=Metropolitan Transportation Authority}} On the other hand, Regional Plan Association prioritized the Lexington Avenue, Crosstown, Eighth Avenue, Fulton Street, Manhattan Bridge, Queens Boulevard, Rockaway, and Sixth Avenue subway lines as those in need of CBTC between 2015–2024. As part of the 2015–2019 Capital Program, the 34th Street and West Fourth Street interlockings on the IND Sixth Avenue Line were completed at a cost of $356.5 million. The interlocking upgrades would support CBTC installation on the Queens Boulevard, Culver, and Eighth Avenue lines.{{Cite web |date=January 22, 2019 |title=Transit & Bus Committee Meeting |url=http://web.mta.info/mta/news/books/pdf/190122_1030_transit-bus.pdf |url-status=dead |archive-url=https://web.archive.org/web/20190120093550/http://web.mta.info/mta/news/books/pdf/190122_1030_transit-bus.pdf |archive-date=January 20, 2019 |access-date=January 19, 2019 |publisher=Metropolitan Transportation Authority |pages=176–177}}

In March 2018, New York City Transit Authority president Andy Byford announced that he had created a new plan for resignaling the subway with CBTC, which would only take 10 to 15 years, compared to the previous estimate of 40 years. However, this would be very expensive, as it would cost $8 to $15 billion.{{Cite news |last=Berger |first=Paul |date=March 29, 2018 |title=New York City Transit Chief: Subway Signal Overhaul Could Be Done in 10 to 15 Years |language=en-US |work=The Wall Street Journal |url=https://www.wsj.com/articles/new-transit-chief-says-signal-overhaul-could-be-completed-in-10-to-15-years-1522315801 |access-date=March 30, 2018 |issn=0099-9660}}{{Cite news |last=Rosenberg |first=Zoe |date=March 29, 2018 |title=NYC Subway's Aging Signals Could Be Fixed in 10–15 Years, Says Transit Head |work=Curbed NY |url=https://ny.curbed.com/2018/3/29/17176200/new-york-subway-signal-repairs-timeline |access-date=March 30, 2018}} Byford subsequently announced his $19 billion subway modernization plan at a MTA board meeting in May 2018. The plan involved upgrading signals on the system's five most heavily used physical lines, as well as accelerating the deployment of ISIM-B to all subway lines that did not already have either automatic train supervision or CBTC.{{Cite news |date=May 22, 2018 |title=A Sweeping Plan to Fix the Subways Comes With a $19 Billion Price Tag |language=en-US |work=The New York Times |url=https://www.nytimes.com/2018/05/22/nyregion/nyc-subway-byford-proposal.html |access-date=May 23, 2018 |issn=0362-4331}}

By 2023, CBTC projects on the entire Crosstown, Lexington Avenue, Archer Avenue IND, and Queens Boulevard lines were planned to be underway. In addition, CBTC work already underway on the Eighth Avenue Line south of 59th Street and on the Culver Line from Church Avenue to West Eighth Street–New York Aquarium would be completed. Moreover, under Byford's plan, the MTA would start retrofitting the entire Broadway Line from Queensboro Plaza to DeKalb Avenue, via both the Montague Street Tunnel and the Manhattan Bridge, the entire Fulton Street and Rockaway Lines, the IND 63rd Street Line, the IND Sixth Avenue Line from 59th Street–Columbus Circle to Jay Street–MetroTech and DeKalb Avenue via the Manhattan Bridge, the IRT Broadway–Seventh Avenue Line south of 96th Street, the Lenox Avenue Line, and a portion of the IRT White Plains Road Line to Jackson Avenue by 2028 at the latest.{{cite web |date=May 23, 2018 |title=Transform the Subway |url=https://static1.squarespace.com/static/5afef986c3c16a2dc6705929/t/5b056a55aa4a99ccc11291bc/1527081560241/Fast+Forward+The+Plan+to+Modernize+NYCT.pdf |access-date=May 23, 2018 |website=Fast Forward |publisher=Metropolitan Transportation Authority}}{{rp|23}} This would require nightly and weekend closures of up to two and a half years for every line that would be affected, although weekday service would be maintained.{{rp|25}} As part of the plan, all subway cars would be CBTC-equipped by 2028.{{rp|26}}

The 2015–2019 Capital Program was revised in April 2018 to fund the upgrade of negatively-polarized direct current cables and the replacement of segments of contact rail with low resistance contact rail along Lexington Avenue to improve power distribution and increase capacity and to upgrade negative cables along Queens Boulevard.{{Cite web |date=November 16, 2018 |title=T7090423 Description: New Negative Side Feeders on Lexington Ave Line |url=http://web.mta.info/capitaldashboard/allframenew_pi.php?PROJNUM=t7090423&PLTYPE=5 |access-date=November 26, 2018 |website=web.mta.info |publisher=Metropolitan Transportation Authority}}{{Cite web |date=November 16, 2018 |title=Description: New Negative Side Feeders on Lexington Ave Line Budget Scope History |url=http://web.mta.info/capitaldashboard/allframenew_budhist.php?PROJNUM=t7090423&PLTYPE=5 |access-date=November 26, 2018 |website=web.mta.info |publisher=Metropolitan Transportation Authority}}{{Cite web |date=November 16, 2018 |title=T7090422 New Low Resistance Contact Rail on Lexington Ave Line |url=http://web.mta.info/capitaldashboard/allframenew_pi.php?PROJNUM=t7090422&PLTYPE=5 |access-date=November 26, 2018 |website=web.mta.info |publisher=Metropolitan Transportation Authority}}{{Cite web |date=November 16, 2018 |title=T7090215 Upgrade Supplemental Negative Cables on the Queens Boulevard Line |url=http://web.mta.info/capitaldashboard/allframenew_pi.php?PROJNUM=t7090215&PLTYPE=5 |access-date=November 26, 2018 |website=web.mta.info |publisher=Metropolitan Transportation Authority}} The draft 2020–2024 Capital Program calls for adding CBTC to several more lines, namely the entire Lexington Avenue Line from 149th Street—Grand Concourse to Nevins Street, the entire Crosstown, the Astoria Line to 57th Street, and the IND 63rd Street line; the IND Fulton Street Line west of Euclid Avenue station; the remainder of the IND Queens Boulevard Line; and the IND Archer Avenue Line. The implementation of CBTC on the 63rd Street Line from 21st Street–Queensbridge to 57th Street and on the Fulton Street Line from Jay Street to Ozone Park had been slated for the 2025–2029 Capital Program. The Astoria Line was not one of the lines originally planned for CBTC installation in the Fast Forward plan.{{Rp|26}}

In December 2021, it was announced that the Sixth Avenue Line between Broadway–Lafayette Street and Jay Street–MetroTech would receive CBTC; funding for this section is not provided in the 2020–2024 Capital Program. In March 2022, the MTA announced that it would install CBTC on the Sixth Avenue Line between Jay Street and 21st Street–Queensbridge.{{cite web |last=Duggan |first=Kevin |date=March 29, 2022 |title=MTA Plans Next Batch of Subway Signal Upgrades |url=https://www.amny.com/transit/mta-eyes-next-batch-subway-signal-upgrades/ |access-date=September 26, 2024 |website=amNewYork}}

On June 9, 2022, the MTA release an RFP for a program management and project management consulting services for the MTA's CBTC program. The base contract included these services for CBTC design–build projects on the Crosstown Line and the Fulton Street Line between High Street and Hoyt–Schermerhorn Streets, while the first three options were for three separate projects to install CBTC on the 63rd Street Line and Sixth Avenue Line between 21st Street–Queensbridge and Jay Street, the fourth consisted of a single project to install CBTC on the entirety of the 63rd Street and Sixth Avenue Lines, while the five consisted of a project to equip two Track Geometry Cars with carborne CBTC equipment. The contract would be for 86 months.{{Cite web |date=June 9, 2022 |title=MTA Construction & Development Notice D81444 SSE No.: 0000396993 Program Management and Project Management Consulting (PMC) Services for MTA C&D Communications Based Train Control (CBTC) Program |url=https://new.mta.info/document/89156 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority}} In June 2022, the MTA announced it planned to solicit a contract on switch replacement and interlocking work as part of the Sixth Avenue CBTC project in 2023.{{Cite web |date=June 27, 2022 |title=C&D Contracting: Upcoming Opportunities |url=https://new.mta.info/agency/construction-and-development/contracting/upcoming-opportunities |url-status=live |archive-url=https://web.archive.org/web/20220628000816/https://new.mta.info/agency/construction-and-development/contracting/upcoming-opportunities |archive-date=June 28, 2022 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority |language=en}}

On July 25, 2022, it was announced that the MTA Board would vote on July 27 on an amendment to the 2020–2024 Capital Program. The amendment would postpone the Lexington Avenue Line and Astoria Line CBTC projects to the 2025–2029 Capital Program and use those funds to install CBTC on the Sixth Avenue Line. MTA officials said that lower peak ridership meant installing CBTC on the Lexington Avenue and Astoria Lines, which was aimed at increasing capacity, was less of a priority as those lines had newer signaling than on the Sixth Avenue Line, which has 80-year old signaling. Another factor in the delay has been delays by subway car manufacturers. Lexington Avenue Line CBTC is reliant on the proposed R262 subway car order, while Sixth Avenue Line CBTC could make use of existing trains and the under-construction R211 trains. With the postponement of the Lexington Avenue Line CBTC project, fewer R262 trains will be ordered. As part of the Sixth Avenue CBTC project, the Jay Street Interlocking will be reconstructed.{{Cite news |last=Guse |first=Clayton |date=July 25, 2022 |title=MTA to Delay Signal Upgrades on Busiest Stretch of NYC Subway, Will Fix Least Reliable Lines Instead |work=New York Daily News |url=https://www.nydailynews.com/new-york/ny-mta-delay-signals-upgrades-busy-nyc-subway-line-20220725-yj6525txdbf4jby7zhwbddv24q-story.html |access-date=July 25, 2022}}

As part of the construction of Phase 2 of the Second Avenue Subway, signaling on Phase 1 would be upgraded to CBTC.{{Cite web |date=June 23, 2023 |title=Phase 2 of Second Avenue Subway Industry Outreach |url=https://new.mta.info/document/113836 |access-date=June 23, 2023 |website=mta.info |publisher=Metropolitan Transportation Authority}} As part of the 2025–2029 Capital Program (announced in September 2024), the entirety of the Broadway, Rockaway, Nassau Street, and Astoria lines would be upgraded to CBTC. These projects would cost an estimated $5.4 billion and would upgrade signals on about {{Convert|75|mi}} of track.

In 2017, the MTA started testing ultra-wideband radio-enabled train signaling on the IND Culver Line and the 42nd Street Shuttle.{{Cite news|url=https://www.nytimes.com/2018/04/23/nyregion/mta-subway-ultra-wideband-radio.html|title=M.T.A. Pins Its Hopes on Unproven Technology to Fix Subway|last=Fitzsimmons|first=Emma G.|date=April 23, 2018|work=The New York Times|access-date=April 30, 2018|language=en-US|issn=0362-4331|url-access=limited}} The ultra-wideband train signals would be able to transmit more data wirelessly in a manner similar to CBTC, but can be installed faster than CBTC systems. The ultra-wideband signals would have the added benefit of allowing passengers to use cellphones while between stations, instead of the current setup where passengers could only get cellphone signals within the stations themselves.{{Cite news|url=http://www.nydailynews.com/new-york/mta-begins-testing-technology-failure-prone-signal-system-article-1.3712208|title=MTA Begins Testing Technology to Help Failure-Prone Signal System|last=Rivoli|first=Dan|date=December 21, 2017|work=New York Daily News|access-date=December 22, 2017|language=en}}{{cite web|url=http://abc7ny.com/2808938/|title=MTA Testing Ultra-Wide Band Radio Technology|last=Burkett|first=N.J.|date=December 21, 2017|website=ABC7 New York|access-date=December 22, 2017}}

The same year, it was reported that full implementation of CBTC systemwide might take 40 to 50 years. Following the subway system's state of emergency that year, MTA Chairman Joe Lhota described the timeline of CBTC installation as "simply too long," instead proposing ways to speed up the work and hosting the Genius Transit Challenge to find quicker ways to upgrade the signals. Some of the proposals included a wireless signaling system, a completely new concept that had never been tested in any other railroad or subway network. In March 2018, the MTA announced that four entities had submitted two winning proposals to the challenge. One of the proposals used ultra-wideband signaling technology. The other proposal entailed installing sensors and cameras on trains, with minimal installations on tracks.{{cite web | last=Vantuono | first=William | title=MTA Genius Transit Challenge winners announced | website=Railway Track & Structures | date=March 12, 2018 | url=http://www.rtands.com/index.php/passenger/commuter-regional/mta-genius-transit-challenge-winners-announced.html | access-date=March 14, 2018}} New York City Transit (NYCT) Chairman Andy Byford stated that he wanted to test ultra-wideband technology at the same time that more established systems, like CBTC, are being installed. In March 2019, contracts for UWB installation on the Canarsie and Flushing Lines were awarded.{{Rp|21–22}} Four trains on each line were equipped with UWB. The MTA then tested the equipment for nine months, and in a January 2020 press release, announced that the test had been "successful".{{cite web|url=http://www.mta.info/press-release/nyc-transit/mta-demonstrates-successful-ultra-wideband-technology-pilot-flushing-and|title=Press Release – NYC Transit – MTA Demonstrates Successful Ultra-Wideband Technology Pilot on Flushing and Canarsie Lines|date=January 23, 2020|website=MTA|access-date=January 26, 2020|archive-date=January 26, 2020|archive-url=https://web.archive.org/web/20200126003512/http://www.mta.info/press-release/nyc-transit/mta-demonstrates-successful-ultra-wideband-technology-pilot-flushing-and|url-status=dead}}

At the May 2020 Capital Program Oversight Committee meeting, it was announced that the two UWB pilot programs, done with different technology and companies, were largely completed, with data collection set to be completed in June 2020. The MTA found that UWB was effective in determining the location of trains, and that it was looking at using it on future projects to replace the transponder-based train localization systems used on existing CBTC projects. UWB would provide more accurate information on the positioning of trains, and allow for simpler carborne installation. In the short term, the MTA was advancing interoperability standards for the new technology. During the pilot program, the MTA investigated the potential use of RADAR, HD cameras and LIDAR alongside UWB.{{Cite web |date=May 2020 |title=Capital Program Oversight Committee Meeting May 2020 |url=https://new.mta.info/document/17496 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority |page=38-39}}

In June 2021, the MTA Board approved the modification of two UWB proof of concept contracts with Thales and Siemens to establish interoperability between the two systems. The MTA deemed that since both systems were found to be acceptable, to encourage competition between the subcontractors for the two companies (Humatics for Siemens and Piper for Thales) and maintain resiliency in the UWB system, it made sense for Humatics to redesign its UWB system to allow its system to communicate and be used with Piper's system.{{Cite web |date=June 2021 |title=Transit and Bus Committee Meeting June 2021 |url=https://new.mta.info/document/42411#page=156 |access-date=July 14, 2022 |website=mta.inof |publisher=Metropolitan Transportation Authority |pages=156–157}} As of March 2023, the interoperability has not yet been demonstrated.{{Cite web |date=March 2023 |title=Capital Program Oversight Committee Meeting March 2023 |url=https://new.mta.info/document/107556 |access-date=June 14, 2023 |website=mta.info |publisher=Metropolitan Transportation Authority |page=105}}

On April 7, 2022, the MTA put out a Request for Information (RFI) looking for information on technology that would allow work trains to efficiently and safely operate on subway lines equipped with CBTC and enable to reduction or elimination of Auxiliary Wayside Signaling (AWS) trip-stops and other standard wayside signaling infrastructure. Currently, work trains, which are not equipped with carborne CBTC equipment, have to make use of the AWS system, consisting of conventional AWS signals, track circuits or axle counters. NYCT conducted a study on equipping work trains with CBTC in 2018.{{Cite web |date=April 7, 2022 |title=RFI-391845 Simplification of the Auxiliary Wayside System ("AWS") and Work Train Modifications for Operation in the CBTC Territory |url=https://new.mta.info/document/82241 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority}}

Another RFI, put out on May 20, 2022, called for proposals to update the existing S733 Signal Standard Specification so it could be simplified for use in CBTC, with a major reduction or elimination of AWS-related work in future CBTC installations. Currently, CBTC is treated under the S733 standard as an overlay of the AWS, and installing the AWS requires a major amount of work.{{Cite web |date=May 20, 2022 |title=RFI-0000397121 Modernizing NYCT's S733 Signal Standard |url=https://new.mta.info/document/87736 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority}}

Finally, on June 1, 2022, the MTA put out an RFI seeking proposals on how to simplify wayside signaling infrastructure to reduce costs for the layout, construction, and design of relay rooms and reduce the need to have track outages to test the completed signaling system before placing it into service. Currently, the MTA equips each relay room with local control panels, programmable logic controllers, a relay-based interlocking system or a solid state interlocking, and zone controllers with related power distribution and network connections. The RFI specified that respondents should consider looking at ways to eliminate as much wayside infrastructure, such as train-stops and line-side signals, including related boxes, relay room-based equipment and lineside cabling, as possible, replace programmable logic controllers and interfaces with logic resting in the Zone Controller or ATS system, eliminate or combine local control panels and related interfaces and equipment, and replace them with remote terminals, reduce or eliminate the number of relays through the use of direct-drive input and output signals, and eliminate or combine other specific room-based equipment.{{Cite web |date=June 1, 2022 |title=RFI-0000398033 Simplification of Wayside Train Control Architecture |url=https://new.mta.info/document/88366 |access-date=July 14, 2022 |website=mta.info |publisher=Metropolitan Transportation Authority}}

{{colbegin}}

• Autopilot
• Application of railway signals
• Institution of Railway Signal Engineers
• Railroad chronometer
• Railway signal
• Railway signalling
• Railroad switch
• Railway semaphore signal
• Railway slide fence
• Toronto subway and RT signals
• Traffic control
• Train speed optimization
• Wrong-side failure

{{colend}}

{{notelist|30em}}

{{reflist|30em}}

{{external media

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|video1={{youTube|id=Mjx3S3UjmnA|title=CBTC: Communications-Based Train Control}} (MTA)

|video2={{youTube|id=J4VnagmUUvI|title=Modernization of the L metro line in New York City}} (Siemens)

}}

• {{Commons category-inline|New York City Subway signals}}
• [http://www.nycsubway.org/wiki/Subway_Signals:_Approach,_Automatic,_and_Marker_Signals Block signaling in the New York City Subway]
• [https://web.archive.org/web/20140202231749/http://www.thejoekorner.com/out-the-front/index-signals.shtm New York City Subway signals]
• [http://www.geniustransitchallenge.ny.gov/sites/default/files/attachments/page-11/brakingstoppingdistance.29.pdf Emergency Brake Stopping Distances For Customer Cars]

{{New York City Subway}}

Category:New York City Subway infrastructure

Category:Railway signaling in the United States

New York City Subway