The controversial idea of electronic road pricing as a way of reducing air pollution and traffic congestion has been debated in Hong Kong for more than two decades. The idea was first proposed in 1983, but public opposition forced the plan to be dropped two years later. The issue was raised again in 1996, when the government spent HK$90 million on a feasibility study, but its long-awaited report concluded in 2001 that there were no grounds for applying electronic tolls. Government officials have repeatedly stressed that electronic road pricing would be feasible only after the proposed Central-Wan Chai bypass was built because it could give motorists a choice of routes. But green groups and harbour activists say road pricing should be adopted first. The Council on Sustainable Development has said it will launch a consultation to collect views from the public on whether an electronic road pricing system should be adopted in an effort to help improve the city's air quality. It will also ask whether other bold measures should be taken to reduce air pollution. Such action might include charging a premium for the use of roads during peak periods, banning the use of diesel-powered vehicles and equipment, and reducing the use of oil-based paints, solvents and cleaners. It is not known when the consultation will begin.