The Thai Department of Highways will begin closing Bhumibol Adulyadej Road (Highway 338) in October 2026 for a 4.63 km elevated expressway project connecting Buddhamonthon Lines 3-4, valued at 4.386 billion baht and expected to complete in 2027. The 4-lane elevated structure will be built in 6 contracts and implemented in phases to minimize traffic disruption on a route handling ~266,000 vehicles daily. This project addresses chronic congestion on Bangkok's eastern flank and will eventually link to motorways M81 and M8, providing alternative routes to southern Thailand.