Since its inception in 1975, the plan has both reduced congestion and stimulated the use of public transportation, at modest cost. The city is replacing the current system with an electronic scheme. Cameras mounted on overhead gateways will automatically deduct entry fees from stored value cards mounted on vehicle dashboards. In OECD countries, road pricing is being considered seriously, although in most places it is still only in the testing phase. In the developing world, the widespread introduction of electronic road pricing may not be feasible because of both the up-front costs of the technology and the potential difficulty of enforcement.
Road pricing can have unintended impacts, however.
For instance, it runs the risk of encouraging travel on roads on which a fee is not required, increasing congestion there and precipitating urban growth in new suburban areas. Road pricing must be examined for its equity impacts as well. By raising the price of travel, peak period pricing may squeeze poorer drivers off the road while allowing those who can afford it to drive on a more efficient road system. Alternatively, the funds generated could be used to reduce transit fares and improve transit service in low-income areas. Taxes and Pollution Fees .