SINGAPORE - All street lights will be fitted with energy-efficient Light Emitting Diodes (LED) by 2022.

The Land Transport Authority (LTA) in a statement on Tuesday said that it will complete the replacement of 4,000 lights at 500 lower-traffic and residential roads by 2018.

By 2019, it will retrofit 25,000 street lights in central Singapore, including areas such as Rochor Road, Kallang Road and New Bridge Road. A tender will be called for the replacement of these lights.

Street lights in all other areas will be replaced by 2022.

An LTA spokesman said the new lights, which will have a white glow, are about 25 per cent more energy efficient than the current conventional high pressure sodium vapour lamps.

The sodium vapour lamps, which have a orange glow, need to be replaced every three years while LED lights, need to be replaced only every decade.

"This helps conserve energy and reduce maintenance and manpower costs," said an LTA spokesman.

The LTA is also developing a remote control and monitoring system that will allow street lights to be more responsive to weather conditions such as heavy rain.

The system, which will also be implemented by 2022, will feature automated fault detection and alert capabilities, that will make the maintenance of street lights more efficient.