Debate has recently raged about using electronic road pricing (ERP) as a substitute for the Central-Wan Chai Bypass. We need both.
No measure alone can serve as a panacea to traffic congestion in the central business districts of major cities. Hong Kong's strategic road network needs the bypass to enhance its connectivity and reliability, and effectively combat traffic congestion both in Central and the neighbouring network, including cross-harbour routes. Although I support ERP as a proven technology, I am not optimistic that it would be easily accepted for use in Central without the bypass.
When traffic flow approaches road capacity, the delay incurred by travellers increases geometrically. A slight increase in traffic leads to a substantial increase in travel cost, and a much higher toll is needed to maximise the benefit of the system. This means that by the time ERP is implemented, remembering that it is no less controversial than the harbour reclamation, the congestion level will have significantly worsened and a substantial toll will be required to achieve maximum benefit.
In contrast, the addition of the bypass would make traffic in Central more responsive, because the east-west through traffic would be more willing to switch to the new route without passing through the busy Central area, which would help lower the optimal toll level of ERP.
Without the bypass, then, ERP could require so high an optimal toll level that it would become socially and politically unacceptable. Traffic congestion would continue to grow. If we really want to ease the traffic congestion in Central and its neighbouring network, we should consider the bypass and ERP as complementary rather than substitutable measures, and build the bypass now to buy time for the serious consideration of ERP. Only in this manner can we arrive at a more effective solution.
S. C. WONG, department of civil engineering, University of Hong Kong