SINGAPORE - A trailer broke down in Upper Serangoon Road on Thursday (Sept 28) morning, resulting in a massive jam.

The Straits Times understands that the trailer, which was carrying concrete slabs, was turning out of a construction site for Build-To-Order development Alkaff Vista onto Upper Serangoon Road when it broke down because of a mechanical fault.

Commuters who posted about the jam on social media as early as 9am said they have been stuck in traffic for at least half an hour.

Bus services were also affected.

SBS Transit said in a tweet at 9.38am that services 13, 100, 107, 133, 135, 147 and 155 will skip bus stops along Upper Serangoon Road towards the city and along Upper Aljunied Road in the direction of MacPherson Road.

It said this was due to a private trailer breakdown that had made the road impassable.

When The Straits Times arrived at the scene at about 10.30am, the trailer was seen taking up all four lanes of the road towards the direction of Serangoon Road.

Police officers were on the scene, directing vehicles to a road diversion via a single lane on the opposite direction of the major road.

Some concrete slabs on the trailer were also being removed and transferred to a lorry, to prepare the trailer for towing.

By 11.30am, the trailer was towed away.

At 11.48am, SBS Transit said in a tweet that the diversions for the affected bus services have ceased.