Bangkok’s Longest Traffic Tunnel Opens Today

City officials ride a bus Tuesday morning through the Mahai Sawan Tunnel in the Thonburi district.

BANGKOK — Traffic in the Thonburi area is expected to flow more smoothly after the Bangkok’s longest tunnel opened Tuesday morning.

The Mahai Sawan Tunnel, which runs parallel to the Somdet Phra Chao Taksin Road to pass under Rama III Road, opened for round-the-clock use by motorists starting today.

An official opening ceremony was presided over by Bangkok Gov. Aswin Kwanmuang, who rode atop a two-story bus to check it out.

The four-lane tunnel runs five meters underground and stretches 1.5 kilometers. The project took over five years to complete.

The tunnel had been open for use during limited hours for several months.