National Highway 1
ทางหลวงแผ่นดินหมายเลข 1
ถนนพหลโยธิน Thanon Phahon Yothin
Route information
Part ofAH1AH2AH12
Length	1,005 km (624 mi)
Existed	1910–present
Major junctions
South end	Bangkok,Victory Monument
North end	Mae Sai district,Chiang Rai, border to Myanmar
Location
Country	Thailand
Provinces	Pathum Thani,Ayutthaya,Saraburi,Lopburi,Nakhon Sawan,Chainat,Kamphaeng Phet,Tak,Lampang,Phayao
Highway system
Highways in Thailand Motorways Asian Highways

Phahonyothin Road (Thai:ถนนพหลโยธิน,RTGS: Thanon Phahon Yothin,pronounced[tʰā.nǒnpʰā.hǒnjōː.tʰīn]) orHighway 1 is a main road inBangkok and one of the four primary highways inThailand, which includeMittraphap Road (Highway 2),Sukhumvit Road (Highway 3), andPhet Kasem Road (Highway 4). It begins atVictory Monument inBangkok and runsnorth to theBurmese border, with a total length of 1,005 km (624 mi).

Phahonyothin Road was originally called "Prachathipat Road" (Thai:ถนนประชาธิปัตย์,Thanon Prachathipat, literally "Democrat Road"), and reached just 22 km (14 mi) toDon Mueang. In 1938, Field MarshalPlaek Phibunsongkhram had the road extended from Don Mueang, throughBang Pa-In, Ayutthaya, Saraburi, Lopburi, andSingburi, making it 162 km (101 mi) long. The newly lengthened road was renamed Phahonyothin Road, in honor of GeneralPhraya Phahol Pholphayuhasena (formerly Phot Phahonyothin), the secondPrime Minister of Thailand and one of the heads of the1932 revolution.^[1]

InBangkok, Phahonyothin Road originates at the northeast corner ofVictory Monument on the periphery ofRatchathewi andPhaya Thai districts, then crossesChatuchak,Bang Khen,Don Mueang, andSai Mai districts before continuing intoPathum Thani Province, and on throughAyutthaya,Saraburi,Lopburi,Nakhon Sawan,Chainat, again through Nakhon Sawan,Kamphaeng Phet,Tak,Lampang,Phayao and finallyChiang Rai, ending inMae Sai district, where it connects toTachileik inMyanmar.

Phaholyothin Road in Bangkok is also a demarcation line between districts or sub-districts in several phases as follows:

1. Thung Phaya Thai (outbound) and Thanon Phaya Thai (inbound) in Ratchathewi district, as a continuation ofPhaya Thai Road, from Victory Monument to the bridge over theKhlong Samsen.
2. Phaya Thai (outbound) and Samsen Nai (inbound) in Phaya Thai district throughout the entire area, from the bridge over the Khlong Samsen to the bridge over the Khlong Bang Sue (begins July 26, 2017).^[2]
3. Chatuchak (outbound) andChom Phon (inbound) in Chatuchak district from the bridge over the Khlong Bang Sue to Ratchayothin Intersection.
4. Lat Yao (outbound) andChan Kasem (inbound) in Chatuchak district from Ratchayothin to Sena Nikhom Intersections.
5. Lat Yao (outbound) andSena Nikhom (inbound) in Chatuchak district from Sena Nikhom Junction to Thong Chanya Bridge.
6. Bang Khen district (outbound) and Sai Mai district (inbound) from the bridge over the Khlong Lam Phak Chi toSaphan Mai quarter.
7. Don Mueang district (outbound) and Sai Mai district (inbound) from Saphan Mai quarter to the administrative boundary line between Bangkok and Pathum Thani.

• Thai highway network
• Kunming-Bangkok Expressway
• Bangkok/Phahonyothin travel guide from Wikivoyage

• Thomas fuller,"In Isolated Hills of Asia, New Roads to Speed Trade",New York Times, March 31, 2008

Wikimedia Commons has media related toPhahonyothin Road.

13°50′51″N100°34′48″E / 13.8474°N 100.5800°E /13.8474; 100.5800

• AH1
• National highways of Thailand
• Streets in Bangkok
• Ratchathewi district
• Phaya Thai district
• Chatuchak district
• Bang Khen district
• Don Mueang district
• Pathum Thani province
• Phra Nakhon Si Ayutthaya province
• Saraburi province
• Lopburi province
• Nakhon Sawan province
• Chai Nat province
• Kamphaeng Phet province
• Tak province
• Lampang province
• Phayao province
• Chiang Rai province

• CS1 Thai-language sources (th)
• Pages using gadget WikiMiniAtlas
• Articles with short description
• Short description matches Wikidata
• Articles containing Thai-language text
• Infobox road instances in Thailand
• Pages with Thai IPA
• Commons category link is on Wikidata
• Coordinates on Wikidata