We refer to Mr Zulhaffeq Zuffean Zamri’s letter “Install countdown timers for safer roads” ( TODAY, 6 June 2014).

Singapore's traffic light system operates on the Green Link Determining System, or "GLIDE", where the duration of green time at a traffic light junction can be varied according to traffic demands, thus allowing for smoother traffic flow. This therefore makes it operationally challenging to implement countdown timers at traffic junctions, as vehicular countdown timers are more suitable for traffic light systems operating with fixed timings.

We had studied the usefulness of using countdown timers at traffic junctions. We have previously conducted a trial at the junction of North Bridge Road and Rochor Road to study the behaviour of motorists towards the countdown timer. The trial showed that motorists displayed varying behaviour when they approached the junction as the countdown timer approaches zero and the lights turn red. Some motorists applied the brakes to stop while others accelerated to beat the light. These observations suggest that the countdown timer may result in a greater likelihood of rear-end collisions at traffic junctions. Studies conducted overseas have also confirmed this observation.

To enhance safety at traffic light junctions, LTA has set a few seconds of an all red period as a buffer in between each change of the traffic light. This is consistent with international practice.

We thank Mr Zulhaffeq for the opportunity to clarify.

Helen Lim (Ms)
Director, Media Relations
Land Transport Authority