LTA's Planning Assumptions for Traffic Impact on Singapore Roads

3 Dr Tan Wu Meng asked the Minister for Transport (a) how does LTA specify the methodology of traffic impact assessments, especially for new housing developments in mature estates; (b) whether the planning assumptions for traffic impact assessments assume a "car-lite" future; and (c) whether a range of vehicle population scenarios is considered when making such assessments.

The Senior Minister of State for Transport (Dr Lam Pin Min) (for the Minister for Transport): LTA requires developers to conduct transport impact assessments (TIAs) to identify the impact of new developments and redevelopments on the surrounding road network and recommend mitigating measures. This applies to both new and mature estates.

LTA publishes guidelines on how developers should conduct the TIAs.

First, developers should establish the baseline traffic demand before the development is built by carrying out a traffic survey. Developers also have to estimate the future growth in traffic volume due to external factors, such as the vehicle growth rate and other new developments in the area.

Second, developers should assess the additional traffic that will be generated by the planned development. This is typically done via surveying a comparable development and adjusting for a lower vehicle mode share if there are future improvements in public transport and active mobility access to the development when it is ready.

LTA does not require the TIA to consider a range of vehicle population scenarios, nor for a specific car-lite scenario. However, by factoring in the vehicle growth rate, which is currently zero for non-commercial vehicles, and enhancements to public transport and active mobility infrastructure in the vicinity, the developments will account for a reduction in the usage of private cars over time.

Dr Tan Wu Meng (Jurong): I thank the Senior Minister of State for his answer. Some mature HDB estates had the road designs, especially the smaller loop roads, built at a time when vehicle norms were quite different from today. As a result, some residents are concerned when there are additional residential developments coming up, such as in the town of Clementi where I serve.

What measures will the Ministry consider to, at least, ensure the vehicle congestion is moderated? Secondly, what measures will the Ministry consider to minimise potential risks to elderly pedestrians arising from increased vehicle numbers?

Dr Lam Pin Min: I would like to thank Dr Tan Wu Meng for the two supplementary questions. LTA does take into account relevant factors, such as new developments and road size, when making TIAs. As what Dr Tan mentioned in his supplementary question regarding size of old roads as well as potential congestion, as part of the TIA, the developer will have to identify the development's impact on the surrounding transport network and recommend necessary measures to mitigate some of these potential negative impact, including congestion, as mentioned by Dr Tan.

Some of these possible transport improvement measures will include staging the developments to prevent a surge in traffic demand or road widening whenever possible and also to encourage the use of public transport and active mobility modes of transport.

As to the second question on how we ensure safety for the pedestrian, whenever possible, LTA will work with URA to build overhead pedestrian networks so that the elderly do not have to cross the busy roads. When overhead link bridges are not possible or not appropriate, LTA will also identify Silver Zones to make our roads even safer for the elderly. To update the Member, we have implemented 15 Silver Zones over the years. We will increase the number of Silver Zones to 50 by 2023. I am happy to work with Dr Tan Wu Meng on the possible plans to make the roads safer for his residents in Clementi.