Phet Kasem Road
Phet Kasem Road (Thai: ถนนเพชรเกษม, RTGS: Thanon Phet Kasem, pronounced [tʰā.nǒn pʰét kā.sěːm])[1] or Highway 4 (Thai: ทางหลวงแผ่นดินหมายเลข 4, 
AH2) is one of the four primary highways in Thailand, along with Phahonyothin Road (Highway 1), Mittraphap Road (Highway 2), and Sukhumvit Road (Highway 3). At 1,310.554 km, route 4 is the longest highway in Thailand.
History
[edit]
The construction of the road was finished in 1950 and was named "Phet Kasem" on December 10, 1950 in honour Luang Phet Kasemwithisawasdi (Tham Phetkasem), formerly the seventh director deputy general of the State Highways Department. Before that, it had been called "Bangkok–Khlong Phruan Road" (ถนนกรุงเทพ–คลองพรวน). Luang Phet Kasemwithisawasdi was the royal scholar of the State Railway Department (now State Railway of Thailand). He studied civil engineering in England and returned to work for the State Railway Department and then transferred to the State Highways Department. Phet Kasem Road was built during the period when Luang Phet Kasemwithisawasdi was the deputy director general of the State Highways Department. The road was named under the policy of the government of Major General Por Phibunsongkhram who named the road after the chief engineer who supervised the construction and gave the instructions.[2]
Route
[edit]Starts at Naowa Chamnian bridge, Bangkok Yai district and goes through the following districts of Bangkok : Phasi Charoen, Bang Khae and Nong Khaem.[3]
The provinces along the road are Samut Sakhon, Nakhon Pathom, Ratchaburi, Phetchaburi, Prachuap Khiri Khan, Chumphon, Ranong, Phang Nga, Krabi, Trang, Phatthalung and Songkhla. It is linked to the North–South Expressway (NSE) of Malaysia at the Sadao-Bukit Kayu Hitam border.[3]
Five sections of the highway are also the Asian Highway AH2 and a single section of highway are also the Asian Highway AH123.
- From Nakhon Chai Si to Ban Pong (Concurrent with AH123)
- From Ban Pong to Ratchaburi
- From Ratchaburi to Cha-am
- From Pranburi to Chumphon
- From Phatthalung to Malaysia border at Bukit Kayu Hitam, where it connects to the North–South Expressway (Malaysia) and Federal Route 1[3]
Rapid Transit
[edit]- The MRT Blue line runs on Phet Kasem Road between the lower platform of Tha Phra MRT station and Lak Song MRT station.
Junction lists
[edit]Legend:
- I/C - Interchange, I/S - Intersection, RSA - Rest and service area, OBR - Overhead bridge restaurant, R/R - Restaurant and rest plaza, L/B - Layby, V/P - Vista point, TN - tunnel, T/P - Toll plaza, BR - Bridge
| Province | District | km | Exit | Name | Destinations | Notes |
|---|---|---|---|---|---|---|
 Bangkok
|
Bangkok Yai | BR | Naowa Chamnian Bridge | Beginning of Phetkasem Road | ||
| Bang Khae |  Motorway 9 / AH2
|
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 Nakhon Pathom
|
Nakhon Chai Si |  Motorway 91 (Planned)
|
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  Hwy 338 / AH2 / AH123
|
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 Motorway 8
|
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| Mueang Nakhon Pathom |  Hwy 375
|
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 Ratchaburi
|
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| Malaysia–Thailand border Through to     North–South Expressway Northern Route / FT 1 / AH2
| ||||||
See also
[edit]References
[edit]- ^ ราชบัณฑิตยสถาน. อ่านอย่างไร และ เขียนอย่างไร ฉบับราชบัณฑิตยสถาน. พิมพ์ครั้งที่ 22. กรุงเทพฯ : ราชบัณฑิตยสถาน, 2557, p. 58. (in Thai)
- ^ The People (2022-09-25). "หลวงเพชรเกษมวิถีสวัสดิ์: ขุนนางเจ้าของชื่อ 'ถนนเพชรเกษม' ทางหลวงแผ่นดินยาวที่สุดในไทย ถูกนำชื่อไปตั้งเป็นชื่อถนนโดยไม่รู้ต้นเหตุในทีแรก" (in Thai). Retrieved 2025-03-21 – via Facebook.
- ^ a b c ความรู้รอบตัว (2012-09-21). "ถนนที่มีความยาวที่สุดในประเทศไทย..." Retrieved 2025-03-21 – via Facebook.
Road infrastructure in Thailand | |||||||||
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| Controlled-access highways |
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| Highways |
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Italics indicate routes under construction. Crossed out names indicate former highways. | |||||||||