Those in the construction industry would be familiar with the exorbitant costs involved in the building of underground civil engineering structures, be they basement carparks or pedestrian crossings.

Hence, I cannot agree with Dr George Wong Seow Choon's suggestion (Construct more underground pedestrian crossings; Oct 18).

Underground works are typically very disruptive, time-consuming and messy.

Furthermore, even if underground pedestrian crossings are built, members of the public would still need to use staircases to get to and from the ground level.

This would not be convenient for the elderly, pregnant and other less-mobile pedestrians, unless escalators are installed as well.

A better alternative would be to build lifts abutting the existing overhead bridges.

There are already quite a few under construction, such as the lift that is being constructed at the overhead bridge at Woodlands Civic Centre, overlooking Woodlands Avenue 5.

Back in 2013, the Land Transport Authority started building and retrofitting lifts at about 40 existing pedestrian overhead bridges islandwide. The authority should continue with this.

The cost savings arising from not building underground crossings will more than pay for the construction and running of lifts at overhead bridges.

Joe Teo Kok Seah