On October 10, the tunneling stage of Hainan’s longest Wuzhishan Tunnel was wrapped up, seven months ahead of schedule.

Due to its challenging geological environment, spanning five fault zones, engineers used a tunnel boring machine to excavate the Wuzhishan Tunnel.The 4.9 km Wuzhishan Tunnel has a two-way design, the left line slightly shorter than the right line, with a total of four lanes. The speed limit is set at 100 km/h.

The bored tunnel is a vital section of the Shanhai Expressway, due to open to traffic this year.The 56 km expressway starts in Wuzhishan City, passes Baoting County and ends in Haitang Bay, Sanya.