Road System in Thailand

Single Digit Route Number

A single digit indicates one of four highways connecting the primate city of  Bangkok to one of the four outlying regions. They are:

Northern Thailand
Highway 1
(Phahonyothin Road)
Bangkok – Chiang Rai and continuing to Tachilek, Myanmar. Part of AH1/AH2.

North-Eastern Thailand
Highway 2 (Mittraphap Road)
Saraburi–Nong Khai as  AH12.

Central, Western and Eastern Thailand
Highway 3 (Sukhumvit Road)
Bangkok–Trat as  AH123.

Southern Thailand
Highway 4: (Phet Kasem Road)
Bangkok–Sadao via Hat Yai.

Two Digit Route Number

Two digits indicate a principal highway within one of the four regions:

Northern Principal Highways
Northern-Eastern Principal Highways
Central, Western and Eastern Principal Highways
Southern Principal Highways

Three Digit Route Number

Three digits indicate a regional secondary highway.

Northern Secondary Highways
Northern-Eastern Secondary Highways
Central, Western and Eastern Secondary Highways
Southern Secondary Highways

Four Digit Route Number

Four digits indicate an intra-Province highway connecting a provincial capital to its districts, or between important sites within the Province.

Northern Intra Province Highways
Northern-Eastern Intra Province Highways
Central, Western and Eastern Intra Province Highways
Southern Intra Province Highways

Roads in Thailand

A listing of all major roads in Thailand.

Asian Highway

The Asian Highway (AH1) runs from Tokyo to Istanbul, a total of 20,557 kilometres.

There is a myriad of offshoots of the Asian Highway numbered from AH2 to AH89. Routes 100 to 299 are part of the ASEAN Highway Network.

These Routes (part) AH1, AH2, AH3, AH 12, AH13, AH15 and AH16, AH123 run through Thailand.

ASEAN Highway

The Association of South East Asian Nations (a political and economic union of 10 coiuntries – ASEAN)  focuses on connectivity between the member countries and a key part of this is the ASEAN Highway Network – part of the Asian Highway Network.

Route Markers

Route Markers show the Route Number and feature the Thai national emblem (a Garuda) above the number.

Kilometre Posts

Single carriageway Lak kilomet (Kilometre Posts) are roadside measurement posts that display the road’s Route Number on the outline of a garuda on a low concrete/stone structure, generally painted white. Some Kilometre Posts also display the Route Number on top. Those located to the left of the carriageway display kilometres remaining to the road’s beginning at kilometre 0. As seen on the right from the opposite lane, the Kilometre Posts ascend in value as one proceeds away from kilometre 0. On edges facing traffic, Kilometre Posts usually show distances remaining to the next two towns, (amphoe seats, or provincial capitals).

Dual carriageway Kilometre Posts are generally located in the median strip or island and show only the kilometre number. They are generally located opposite the roadside Kilometre Posts.

Rural Roads

Rural Roads usually form intra-province links, and have four-digit route numbers with a two-alphabet prefix denoting the province.

More than Bus Shelters


© Kim Epton 2024
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