The Phuket HIghways Office explained in an announcement that the inspection was routine, and necessary to ensure the pump system remains operational, especially as Phuket continues to experience heavy downpours during the rainy season.
The underpass will be closed to traffic from 9am to 5pm so workers can carry out the inspection, the Phuket Highways Office said in its announcement.
The Phuket Highways Office apologised for any inconvenience caused by the tunnel closure.