The Bus Rapid Transit Project in Bangkok: A Case of Traffic Misallocations?

The Bus Rapid Transit (BRT) for the Satorn/Rajpruek route in Bangkok is characterized by four inbound lanes and four outbound lanes separated by a traffic island. The lanes adjacent to the traffic island are designated as the BRT lane where no vehicles, except the BRT buses, are allowed access. The BMA anticipated that the project will reduce the number of vehicles along the Satorn/Rajpruek route which is the major reason used to justify the project. Granted that the BRT project can reduce the number of vehicles along the route it also causes traffic misallocations by causing too few vehicles in the BRT lane and too many vehicles in the remaining lanes which result in welfare losses. It is proposed that all vehicles are allowed access to the BRT lane if their drivers are willing to pay a ‘second best' congestion charge. The drivers that are not willing to pay the congestion charge still have free access to the remaining lanes. It is shown that the second best congestion charge can reduce welfare losses from the traffic misallocations when compared to the original BRT project. The second best congestion charge offers an option for vehicle users to be better off by accessing the BRT lane. If they are not willing to pay the congestion charge to access the BRT lane they still have free access to the remaining lanes and, hence, are not worse off than before.