Thai highway network#Northern Thailand

The 1992 Highway Act ({{langx|th|พระราชบัญญัติทางหลวง พ.ศ. 2535}}), revised as the 2006 Highway Act ({{langx|th|พระราชบัญญัติทางหลวง (ฉบับที่ 2) พ.ศ. 2549}}), defines the following five highway types:[http://www.doh.go.th/dohweb/data/data_1.html DOH website, ประเภททางหลวง], retrieved on November 13, 2008 {{webarchive |url=https://web.archive.org/web/20111211173759/http://www.doh.go.th/dohweb/data/data_1.html |date=December 11, 2011 }}

A special highway ({{langx|th|ทางหลวงพิเศษ}}) or motorway is a high capacity highway designed for high speed traffic, for which the Department of Highways carries out construction, expansion, upkeep and repairs, and is registered as such. Motorway entrances and exits have controlled access, and controlled by the DOH. Registration of motorways is overseen by the Director General of the DOH.

A national highway ({{langx|th|ทางหลวงแผ่นดิน}}) is a primary highway, part of the network connecting regions, provinces, districts, and other important destinations, for which the DOH carries out construction, expansion, upkeep and repairs. Registration of national highways is overseen by the Director General of the DOH.

A rural highway ({{langx|th|ทางหลวงชนบท}}) or rural road is a highway for which the Department of Rural Roads carries out construction, expansion, upkeep and repairs. Registration of rural highways is overseen by the Director General of the DORR.

A local highway ({{langx|th|ทางหลวงท้องถิ่น}}) or local route is a highway for which the local administrative organization carries out construction, expansion, upkeep and repairs. Registration of rural highways is overseen by the provincial governor.

A concession highway ({{langx|th|ทางหลวงสัมปทาน}}) is a highway for which a legal government concession has been granted. Registration of concession highways is overseen by the Director General of the DOH.

The first digit of a highway number indicates the region of Thailand it serves, with the number of digits indicating the highway classification.{{cite web|title=ระบบหมายเลขทางหลวง|url=http://www.doh.go.th/content.aspx?c_id=3&sc_id=11|work=Department of Highways website|publisher=Department of Highways|accessdate=13 August 2011|url-status=dead|archiveurl=https://web.archive.org/web/20111005100851/http://www.doh.go.th/content.aspx?c_id=3&sc_id=11|archivedate=5 October 2011}} These regions are:

A single digit indicates one of four highways connecting Bangkok to outlying regions:

The Highway number system specifies the use of 4 digits to refer to highways. By dividing highways into 4 sub-levels as follows:

{{Expand section|date=May 2024}}

Sign on Thailand road 12.JPG|Sign on Route 12 in the north of the country

Road 108 new construction Mae Hong Son province.JPG|Bridge construction on route 108

2013 AH16 Thai Highway 12.jpg|Route 12/Asian Highway 16 in Phetchabun Province being widened (2013)

{{clear}}

File:Thailand AH1 AH2 Route 32 Ayutthaya.JPG, AH2 and Highway 32 in Ayutthaya]]

{{clear}}

File:Pattani Bypass Highway.jpg in Pattani Province]]

{{clear}}