The idea that a distance-based Electronic Road Pricing (ERP) system is inequitable for less affluent people living farther away from the city and therefore an unfair burden is overly simplistic and incorrect (Distance-based ERP burdens majority living in suburbs by Dr Jeremy Teo Chin Ghee, Sept 12).

The current ERP system charges more for people living farther away from the city through multiple ERP gantries on an expressway.

Dr Teo may be confused about the satellite, distance-based technology being used for the purpose of first, replacing the less equitable road tax structure, and second, replacing physical ERP gantries, which are for alleviating congestion in certain areas.

Based on Dr Teo's reasoning, MRT fares should then be a flat fee regardless of distance travelled and so should taxi fares. Residential property, commercial property rental prices and delivery and courier costs should also not consider the location factor.

The mistaken view that the less affluent live farther away from the city centre is an unhelpful generalisation in this case. Owning a car is also not an essential good in Singapore, with our world-class public transport system.

We must also not forget the market pricing mechanism, which leads to a more efficient allocation of resources, and the Government's efforts to provide equitability through numerous policies and measures, such as a progressive income tax structure, grants, subsidies and reliefs.

Distance-based road charging is equitable. Furthermore, the pricing structure should be progressive, similar to our income tax structure. This will bring greater equitability and also obliges us to be more responsible for the environment.

Chew Kwok Choong