Number one main highway is a highway between the cities, the main link between Bangkok to each region of the country. There are a total of 5 lines from No. 5 to no. 8 and no. 9, which is a ring road, ropnokkrungthep Bangkok.
Motorway single digit The main highway between the cities. Linking Bangkok to each region of the country. A total of five routes from No. 5 to No. 8 and No. 9, the Outer Ring Road, Bangkok.
The main motorway number one. A special highway. The connection between the metropolitan to each region of the country, there were 5 road from number to number and 9 5 8 number which is the outer ring road, Bangkok.