Formally known as the “Mega Bridges” the £128 million Bhumibol Bridges connect the industrial area of Samut Prakan with the Port of Bangkok.

Two cable stayed bridges, with main spans of 398m and 326m, connected by a high level viaduct carry dual three lane carriageways with an additional climbing lane on the approaches. The concrete pylons are diamond shaped with two planes of stay cables that support the outer edges of the main span decks. The overall length of the two crossings together with three elevated approaches is approximately 5km.

Between the two bridges an elevated central interchange connects the main North-South route with the western approach. The three approaches are designed as continuous concrete box girders with spans varying between 64m for the high level viaducts to 36m for the lower level viaducts.

H.M. The King has granted the name Bhumibol 1 to the northern bridge across the Chao Phraya River linking Bangkok and Samut Prakan, and the name Bhumibol 2 to the southern bridge that links Phra Pradaeng City and Samrong Tai Sub-district. The two bridges are part of the Industrial Ring Road that connect Rama III Road to Poochao Samingphrai Road and Suksawat Road. In the middle there is an interchange taking traffic to and from Suksawat Road in Phra Pradaeng.