What type of thoroughfare is Phet Kasem Road?

It is a primary national highway. The route spans the greatest distance of any highway in Thailand.

Which other routes belong to the same primary highway group in Thailand?

Thailand classifies Phahonyothin Road, Mittraphap Road, and Sukhumvit Road in the same primary highway tier.

Who is the road named after?

Luang Phet Kasemwithisawasdi, also known as Tham Phetkasem, inspired the name. He worked as deputy director general for the State Highways Department.

What was the earlier name of this route?

The route originally carried the name Bangkok–Khlong Phruan Road.

Why did the government name the highway after Luang Phet Kasemwithisawasdi?

Official government policy under Major General Por Phibunsongkhram assigned highway names based on the chief engineers responsible for guiding construction.

Bangkok · Thailand

Phet Kasem Road: what's nearby, how to get there and when to go · 2026

Residents along Phet Kasem Road trade quiet side streets for relentless arterial traffic, timing daily routines around bus lines to navigate the long corridor into the city center.

Phet Kasem Road · CC BY-SA 4.0

Map of places

Around here1

Exchange rate฿33.76per 1 $THB — the local currencyas of Nov 2, 2026

Within two hours

Krungthep Bridge≈ 40 min Wat Suthat≈ 40 min Sanam Luang≈ 40 min Yaowarat Road≈ 40 min Assumption Cathedral≈ 40 min

About the place

The longest highway in the country begins as a dense metropolitan transit corridor before connecting the capital to the southern border.

Phet Kasem Road ranks as the longest highway in Thailand, standing alongside Phahonyothin Road, Mittraphap Road, and Sukhumvit Road among the primary national routes. Early travelers knew the corridor as Bangkok–Khlong Phruan Road before official renaming ceremonies established its modern identity. For new arrivals living along the Bangkok section, the road acts as an unending spine of commercial activity and bus traffic.

Read on

The administration of Major General Por Phibunsongkhram established a policy of dedicating major highways to the chief engineers who directed their construction. The road honours Luang Phet Kasemwithisawasdi, a royal scholar of the State Railway Department who completed civil engineering studies in England. He supervised construction while serving as deputy director general of the State Highways Department.

Associations

Luang Phet KasemwithisawasdiThe State Highways Department engineer who directed initial construction.
Bangkok–Khlong Phruan RoadThe historical designation used for the thoroughfare prior to official renaming.
Major General Por PhibunsongkhramThe prime minister who instituted naming highways after supervising engineers.
Southern highway corridorTravelling the entire southern overland route requires extensive journey time.

Facts

Phet Kasem Road is the longest highway in Thailand.
The route was designated as Bangkok–Khlong Phruan Road prior to official renaming.
Luang Phet Kasemwithisawasdi studied civil engineering in England before supervising highway construction.
The government under Major General Por Phibunsongkhram established a policy naming highways after chief engineers.

Updated September 10, 2026Source: Wikipedia

Phet Kasem Road: what's nearby, how to get there and when to go · 2026

What is around1

The longest highway in the country begins as a dense metropolitan transit corridor before connecting the capital to the southern border.

Getting there and staying

Similar nearby