The Department of Highways has signed the contract to build an interchange with an underpass at Nong Chom intersection in Chiang Mai, where Highway 121 crosses Highway 1001. The Bridge Construction Bureau signed with Chiang Mai Construction Co Ltd for 799.599 million baht. The contract runs from October 10, 2026 to September 23, 2029, which works out to 1,080 days. For a junction that sees a great