Traffic solution over the top

China's urban traffic problem is worsening now that the country has become the world's biggest car market. If you can't go under it and you can't overtake it, rise above it.

Trials of the 3D Express Coach are expected to begin this year.

Beijing // At first glance it looks like something out of a 1970s science fiction film - the type of futuristic invention dreamt up by an over-imaginative scriptwriter that is never likely to become reality.

But the "3D Express Coach" is not a celluloid dream. It is a deadly serious proposal and the answer, one Chinese company says, to the country's increasing traffic congestion problems and possibly those in other parts of the world. Never mind if the roads are jammed with cars sitting bumper to bumper, this bus can go straight over them. Shenzhen Huashi Future Parking Equipment has said trials of the bus could begin this year, and it hopes the vehicles could be adopted in many of China's cities.

Officials have also said it could help alleviate traffic congestion in the UAE. The 3D Express Coach is designed to travel at up to 60kph with as many as 1,400 passengers able to use the network at once. They would board from platforms on either side of the bus, or above it, walking down steps into the passenger compartment. Running partly on solar power, the vehicle is designed to also use basic mains electricity, reducing the need for additional power installations, and would move from one "charging post" to the next.

The bus would run on either rails - the preferred option as it would make the vehicle more efficient - or by white lines that an autopilot would be able to follow precisely. Song Youzhou, the chairman of Shenzhen Huashi, says the primary benefits of the bus include the fact that there is no need for a special bus lane so it does not add to the road congestion. The company insists the bus also saves energy, with each vehicle cutting the amount of fuel burned annually by 860 tonnes, based on the number of car journeys it eliminates.

The quantity of carbon emitted each year is cut by more than three times this amount, it is claimed. Shenzhen Huashi claims the 3D Express Coach could cut congestion on China's roads by up to 30 per cent. Although Beijing cut its metro underground fares several years ago and bans vehicles from using the roads on particular days according to number plates, rapid growth in vehicle ownership is countering these measures.

Last year, China overtook the US to become the largest car market in the world and in the first six months of this year vehicle sales in China increased a further 47 per cent to 9 million. But while the need for measures to reduce congestion is acknowledged, analysts are unsure as to whether the bus is the solution. John Zeng, a Shanghai-based motor industry specialist at the research organisation JDPower and Associates, says the bus is generally "a good idea", especially as it could travel in all traffic conditions.

Mr Zeng says a major problem on the roads in China, and in countries such as the UAE, is lane discipline among drivers. Chinese drivers, he suggests, would find it difficult to cope with the restrictions of driving through the 3D fast bus. "The system could do quite well if it was running in say, Germany or the US, where people [respect] the right of way and drive properly," he says. "It relies on the drivers following the rules, following their own lanes and not changing lanes.

"If you put this system in Shanghai or Beijing, you will worry about the behaviour of the drivers. They are quite aggressive. They will probably ruin the system." Shenzhen Huashi says alarms would sound if a car got too close or if a vehicle that was too tall was trying to drive under the bus, while warning lights would flash to warn drivers the vehicle was about to turn. Drivers would then be able to turn with the bus.

Barbara Siu, an urban planning and transport specialist in the department of civil and structural engineering at the Hong Kong Polytechnic University, admires the 3D Express Coach, describing it as "an interesting innovation". But Ms Siu wonders whether it could actually make it on to the roads. She says the bus would struggle with sharp turns, might find it hard to cross wide intersections and may not be able to pass through tunnels.

The cost of producing the buses could be prohibitive, Ms Siu says, as the walls may need to be made with very high-strength steel or other materials to support a fully loaded vehicle. But the company claims the buses are financially feasible. A 40km stretch of track and the buses to run on it would cost 500 million yuan (Dh270.2m), the firm says, while an underground of the same length would cost about US$2.5 billion (Dh9.18bn) to build in China.

Ms Siu also says the departure platforms would be expensive and may be difficult for elderly or disabled people to access. "I think a lot of work needs to be done before this straddle bus can really run on the road," she says. [e-mail]