From rope bridges and 12m poles to lower speed limits of 20kmh to 40kmh, measures have been put in place along Mandai Lake Road in the past two years to facilitate safer wildlife crossings.

They are part of efforts by Mandai Park Development to minimise instances of roadkill and human-animal conflict along the often busy road.

Since work started on the Mandai rejuvenation project, which borders the Central Catchment Nature Reserve, nature groups suspect forest-dwelling animals have moved out of their natural habitat because of disturbance from the works.

There have been instances of wildlife killed in collisions with vehicles. In the latest incident this week, a sambar deer was run over by a motorcycle, making it at least the third such incident this year.

But Mandai Park Development hopes the measures will reap results over time.

For instance, the high poles installed along the sides of the road allow colugos - flying lemurs that leap from tree to tree - to move as they would in a forested area.

These poles are designed to mimic tree trunks and have been put up along known colugo paths.

"Roads are an obstacle to colugos, and the poles have since been designed to allow them to leap from tree to tree," said colugo expert Norman Lim.

Observations reveal that the nocturnal colugos do use the poles. The structures will be in place until construction is completed.

Besides the lower speed limits, there are also 50m-long rope bridges to enable small animals such as monkeys to cross the road, and 30m-wide ground crossings that bypass the busy road and lead to the west of the construction area.

Dr Lee Hui Mien, Mandai Park Development's vice-president of sustainable solutions, said: "We have observed a significant number of animals using the ropeway and the other safety features."

Permanent features will also be installed, including an elevated wildlife crossing, which is like an overhead bridge.

Dr Sonja Luz, director of conservation, research and veterinary services at Wildlife Reserves Singapore, said it is necessary to give animals room to move from one forested area to another. Wildlife connectivity measures are especially vital in Singapore, where nature is often fragmented by urban development and building works.

"It is a huge undertaking, but we need to find a way for humans and animals to sustainably co-exist in the same environment," Dr Luz said.

Correction note: This article has been edited for clarity.