Phet Kasem Road
Phet Kasem Road or Highway 4 is one of the four primary highways in Thailand, along with Phahonyothin Road, Mittraphap Road, and Sukhumvit Road. At 1,274 km, it is the longest highway in Thailand. It begins at Naowa Chamnian bridge in Bangkok Yai, Bangkok. It is named after Luang Phet Kasemwithisawasdi, the seventh director general of the Department of Highways.
The provinces along the road are Samut Sakhon, Nakhon Pathom, Ratchaburi, Phetchaburi, Prachuap Khiri Khan, Chumphon, Ranong, Surat Thani, Phang Nga, Krabi, Nakhon Si Thammarat, Trang, Phatthalung and Songkhla. It is linked to the North–South Expressway of Malaysia at Sadao and Bukit Kayu Hitam passes.
Three sections of the highway are also the Asian Highway AH2.
