Bangkok is divided by the Chao Phraya River into the main eastern part and Thonburi in the west, with several road bridges linking both sides of the city. By the mid-1990s, traffic congestion on these crossings had become particularly severe. Phra Pinklao Bridge, in particular, was regarded as the worst. With suggestions from King Bhumibol Adulyadej, the Bangkok Metropolitan Administration commissioned studies for the construction of a new bridge north of Phra Pinklao Bridge to alleviate that congestion.