Thailand Road Network

By | December 19, 2022

According to wholevehicles, Thailand has a fairly dense road network, partly due to the many small and medium-sized cities that contribute to a high population density in Central Thailand. The road network comprises approximately 68,000 kilometers of road, the vast majority of which is paved. There are relatively few highways in Thailand, a distinction is made between motorways, which are highways and which are usually subject to tolls. In addition, there are expressways, which are sometimes developed as a highway, especially around Bangkok, and are often 2×2 or 2×3 main roads with at-grade intersections. The network of the expressways is quite extensive and almost all areas and larger cities are served by such roads. The motorways are only around Bangkok.

The road network is clearly centered on the capital Bangkok. Several highways run through the city, via spectacular bridges. Although there is no real ring road, there are several bypasses. The highways in Bangkok are usually built with 2×3 or 2×4 lanes. Many highways run on viaducts over the city, the longest viaduct construction in the world runs in Bangkok with a length of 42 kilometers. Despite the fact that there are a number of highways in Bangkok, the city has huge traffic jams, often lasting all day. A problem is the poor separation of non-motorized traffic and fast traffic, narrow streets, irregular intersections and poor compliance with traffic rules that regularly lead to gridlocks.

Main road network

Road number of a main road.

Outside Bangkok there are mainly expressways, which are often partly developed as a highway. The roads sometimes have a somewhat illogical route formation, and are often partly replaced by shorter roads.

Highway 1 runs from Bangkok to the border with Myanmar at Mae Sai and is 1,007 kilometers long, most of it as a 2×2 expressway. Highway 2 branches off Highway 1 just north of Bangkok and runs to the border with Laos at Nong Khai and is 537 kilometers long, and has been developed as an Expressway except for the last 60 kilometers. Highway 3 runs from Bangkok to Trat, and is 360 kilometers long, the first 60 kilometers after an Expressway. Longer is Highway 4, which runs from Bangkok to the border with Malaysia for 1,280 kilometers and has been developed as an Expressway over the first 485 kilometers and the last 75 kilometers.

Other major 2×2 roads include Motorway 9 which forms a 72km western bypass of Bangkok, Highway 11 which runs 106km from Lampang to Chiang Mai, Highway 32 which runs 180km from Bangkok to Nakhon Sawan, Highway 340 from Bangkok to Suphan Buri about 70 kilometers and Highway 344 from Chonburi to Klaeng about 105 kilometers.

National Highways in Thailand
1 • 2 • 3 • 4 • 6 • 7 • 9 • 11 • 12 • 21 • 22 • 23 • 24 • 31 • 32 • 33 • 34 • 35 • 36 • 37 • 38 • 41 • 42 • 43 • 44 • 81 • 82

Motorway network

Road number of a toll-free highway.

Road number of a toll highway.

The real motorway network is the motorways, of which only a small number have this status. Nevertheless, expressways can have highway status. Motorway 7 is a toll highway from Bangkok via Chonburi and Pattaya to Rayong over 162 kilometers and runs parallel to Highway 34, which has also been extensively developed. Motorway 9 is a 66 km motorway on the east side of Bangkok and together with the rest of Motorway 9 forms a 170 km long ring highway around Bangkok, although it is more of an elongated oval than a real ring road.

There are plans to drastically expand the motorway network to 4,155 kilometres. Highway 5 is to become a 756 kilometer motorway between Bangkok and Chiang Mai and partly replace the existing Highway 1. Motorway 6 should run from Bangkok to the border with Laos at Nong Khai, replacing Highway 2. Highway 8 is to replace Highway 4 and other roads and run south from Bangkok to Songkhla over 951 kilometers.

Double lane roads in Thailand are called an expressway in English. However, they are not of the same design standard as the expressways in China, India or Malaysia, for example. The term expressway in Thailand refers to a double-lane road, which is usually not completely grade separated. Actually, the British term dual carriageway is more appropriate than the term expressway, which in most countries means a completely grade separated road. The network of double-lane roads in Thailand is extensive, almost all main roads from Bangkok are an expressway to all corners of the country.


On November 23, 2015, a road plan was unveiled for the construction of 6,612 kilometers of motorway between 2016 and 2036. This plan will cost 2100 billion baht (€55 billion). Also in this plan a new numbering of the 21 planned motorways has been announced, with M numbers ranging from M2 to M92.

Expressways and motorways in Thailand
Highway 1 • Highway 3 • Motorway 6 • Motorway 7 • Motorway 9 – Bangkok Ring • Highway 31 • Highway 35 • Motorway 81 • Motorway 82 • Highway 338Bang Na Expressway • Bang Sue – Taling Chan Expressway • Chalong Rat Expressway • Nakhon Expressway • Sirat Expressway • Uttaraphimuk Elevated Tollway (Don Mueang Tollway)

Asian Highways

Asian Highways in Thailand
AH1 • AH2 • AH3 • AH12 • AH13 • AH15 • AH16 • AH18 • AH19 • AH112 • AH121 • AH123

Road numbering

National Roads 1 to 4 are the radial roads of Bangkok and run in a spider web to the north, northeast, southeast and south respectively. The two-digit roads are branches of the single-digit major roads and are thus zoned. Three-digit roads are in turn branches of two-digit roads. There is not a very good hierarchy, three-digit roads can also be developed as highways and form important routes. In general, the higher numbers are shorter than the lower numbers.


The signage is mostly in Thai and English. Thai is represented in a different script, the Thai script. Some signs are only in Thai. Highways have green signposts with white letters, local roads have white signs with black letters.

Road signs

A mix of American and European road signs are used in Thailand.

Maximum speed

The speed limit in Thailand is 60 km/h within built-up areas and 90 km/h outside built-up areas. The speed limit on motorways was previously 90 km/h, but in 2021 the maximum speed on motorways has been increased to 120 km/h.

Thailand Road Network