The government has proposed electronic pricing to reduce traffic and smog, but still demands Central-Wan Chai bypass Mention transport in Hong Kong and thoughts often turn to impeccably clean trains that run on time, buses and minibuses available to every conceivable destination and a giant fleet of taxis mercifully powered by Toyota's liquified petroleum gas engines. Yet much to the chagrin of residents, visitors and - presumably - the Hong Kong tourist board, an equally valid image of travel in the territory is one of traffic jams and the lung-filling roadside pollution that inevitably accompanies them. Last week, the government proposed via its council on sustainable development a bundle of measures to tackle the territory's worsening air pollution problem, including one technology discussed and tested ad nauseum for more than two decades, but yet to be deployed beyond tunnels in the territory - electronic road pricing. Specifically, the council suggested using electronic road pricing to cut traffic volume during peak times, banning private vehicles from congested areas at certain times and levelling out cross-harbour tunnel charges. 'Hong Kong was for a long time well ahead of the game in developing this technology,' said Andy Green, chief technical officer at Hong Kong-based transportation technology experts KG Intelligent Systems (KGIS). 'Now other cities - most notably London - have deployed electronic road-pricing systems and are already reaping the benefits in the form of reduced congestion and pollution.' The theory underlying electronic road pricing is part of an area of economics known as 'externalities', the idea that in a congested environment the decision by one user to drive carries with it an 'external' cost that is greater to other drivers and society as a whole - in the form of added congestion and pollution - than the cost to that individual user. Electronic road pricing is one means proven to 'internalise' the costs of road usage so they are borne by road users themselves rather than by society as a whole. Cities that have implemented such systems have seen a reduction in overall traffic numbers and pollution-inducing congestion. 'Electronic road pricing works because there is a clear correlation between the way people use their cars and the way they are charged for using them,' Mr Green said. 'Other road pricing instruments, such as registration [charges], affect the infrequent user the same as the frequent [one], so there's limited incentive to cut back the number of journeys made by car versus, say, public transport.' It is not a new phenomenon. The economic rationale for efficient road use was clear even to Julius Caesar when he decreed the centre of Rome off limits to all but approved vehicles in peak hours, a rule that was later extended to all towns throughout the Roman Empire by Marcus Aurelius (he of Gladiator fame.) Hong Kong first tested electronic road-pricing technology in 1983, using a system of electronic loops built into the surface of the roads which collected data from cars as they passed overhead. While the technology was deemed viable, the scheme was never implemented due to intense opposition from motorists. Nowadays, road pricing technology essentially falls into two camps - Dedicated Short-Range Communications (DSRC) system, and the more advanced Vehicle Positioning System (VPS). Based on the maturity of the technology and cost of implementation, DSRC systems are currently the most widespread. The technology is particularly suited to charging users on specific roads, with flexibility to charge users according to variables such as engine type, time of day or - as in last week's government proposal - according to the level of pollution on a particular day. The most recent study in Hong Kong published in 2001 - based on a DSRC deployment on the old Kai Tak airport - estimated that '40 per cent of car trips in the morning peak may be diverted to public transport and 10 per cent may change time of travel. The remaining 50 per cent may stay-and-pay the road user charges but will benefit from higher travel speeds and less congestion.' Elsewhere, however, more advanced location-based systems are gaining traction as governments see the advantage of building pricing models around precise movements in a zone - charging users more for making many short trips to the city centre, for example, than someone who enters and parks. Yet equally significant is the idea that location-based systems could spawn a range of commercial services that could help pay for the cost of deployment. Individual vehicles' detailed road-use history could be sold to insurance companies to enable more sophisticated risk-pricing analysis, for example. In Japan, information pooled from the electronic road-pricing infrastructure on the country's highways is already routed to private vehicles' navigation systems, further reducing congestion. According to Deloitte Consulting, the integration of location-based charging systems with other smart transportation technologies, such as unified payment systems and traffic control measures, is a logical development that could ultimately lead to fully automated transport networks. In the meantime, experts agree that electronic road pricing is not the only potential solution to Hong Kong's congestion problem. 'Not all measures have to be financial,' said Hung Wing-tat, a Polytechnic University associate professor of civil and structural engineering. 'Flexible working hours can be very effective if the government and corporations get behind it ... another method would be to limit the hours that lorries are allowed into the central business area. In Hong Kong this would reduce traffic by 20 per cent but would require a lot of negotiations with companies and trade representatives.' KGIS' Mr Green said Hong Kong could implement a number of other measures at little cost to improve congestion. 'Tunnel tolls have already had a dramatic impact on traffic management, so tweaking the tolls to even the traffic flow is the very least that could be done,' he said. 'More innovative measures could be increasing the tunnel tolls on heavy pollution days while simultaneously making cross-harbour MTR journeys free, or even subsidising taxi fares on those days.' It appears unlikely, however, that electronic pricing or any other means will be sufficient to deter the government from building the Central-Wan Chai bypass. The government's position remains that even a bundle of measures, including electronic road pricing, would be insufficient to deal with the problem of congestion without the construction of the Central-Wan Chai bypass. 'The implementation of ERP [electronic road pricing] would require the presence of an alternative route first,' said Deputy Secretary for the Environment, Transport and Works, Thomas Chow, last year. He said introducing ERP in the Central-Wan Chai area would be 'unfair' on motorists trying to travel from, say, Sheung Wan to Chai Wan. But according to Mr Green, studies have shown that up to 50 per cent of traffic on new roads represents new vehicles - that people buy cars to take advantage of new roads. He said new technology enabled the creation of 'virtual bypasses', whereby software could ensure that motorists who passed through an electronic road-pricing area without stopping were not charged. Annelise Connell, chairperson of Clear The Air, said the government had not done enough to educate car owners about electronic road pricing. She also criticised the decision to remove the public consultation from an electronic road pricing study concluded in 2001. 'You can reduce traffic without the bypass,' she said. 'This [electronic road pricing] is something they should have started in 2001 - the public is ready and even the Automobile Association is in favour. Only the government seems to prefer the idea of building a bypass.'