Ever wonder how a pothole is formed and why we have more of them during raining seasons?

Potholes form when water seeps through tiny pores on the road surface into the asphalt pavement. During rainy seasons when the top layer of the pavement is soaked in water as a result of prolonged rainfall, the composition of the top layer is weakened and clusters of aggregates may be loosened and subsequently removed by traffic running over it. Potholes are therefore more evident during rainy seasons.

Potholes are repaired by first power saw-cutting the affected area and removing all loosened aggregates.

A layer of tack coat is applied followed by hot fresh premix, before the filled area is compacted. Prior to the actual repair, the affected road lane will be closed temporarily with proper traffic control including, the use of a Truck-Mounted Attenuator (TMA) for expressways and roads with speed limits of 70km/h or above.

Due to the nature of the material, potholes cannot be properly repaired under wet conditions as the tack coat laid is unable to bind the existing surface and the fresh premix together effectively, and the fresh premix will be washed away by rainwater.

LTA targets to repair potholes within 24 hours upon notification. However, during days of prolonged rainfall, the contractor may do a temporary reinstatement (just laying the tack coat and filling the hole with asphalt) and come back again during dry weather conditions to do a proper permanent repair.

LTA carries out regular inspections on the roads.

Daily inspections are carried out along expressways such that any particular stretch will be inspected at least once a week. Inspections are also carried out once every two weeks for major roads and once every two months for minor roads.

Motorists should be alert and drive carefully especially during raining days.

If you spot any pothole on the roads, please call LTA Customer Service Line at 1800-CALL LTA (1800-2255582).