Thursday, August 19, 2010

China's road-straddling tunnel-bus

My cousin, who follows all things China, sent this to me a couple of weeks ago, and it's since been making the rounds in the blogosphere: a bus that straddles the roadway, allowing cars to pass underneath it:
Proposed by Shenzhen Hashi Future Parking Equipment Co., Ltd, the model looks like a subway or light-rail train bestriding the road. It is 4-4.5 m high with two levels: passengers board on the upper level while other vehicles lower than 2 m can go through under. Powered by electricity and solar energy, the bus can speed up to 60 km/h carrying 1200-1400 passengers at a time without blocking other vehicles’ way. Also it costs about 500 million yuan to build the bus and a 40-km-long path for it, only 10% of building equivalent subway. It is said that the bus can reduce traffic jams by 20-30%.
Here is a video of the proposed vehicle with an English translation:

At first glance, I think it's a fascinating concept. But the devil is in the details, and the information currently available about this concept provides precious little in the way of specifics. For example:

How does this massive thing turn? The video indicates that the vehicle is articulated, but given its size it still seems like it would need a tremendous turning radius.

What about the time and cost associated with the removal and relocation of traffic lights, bridges, power lines, trees, etc. necessary to give this 4.5 meter (about 18 feet) sufficient vertical clearance?

What about the manner in which other motorists interact with it? Moving through a tunnel that itself is moving is bound to be a disorienting experience to drivers. There are supposed to be sensors on this contraption to warn motorists if they get too close to the edges of the vehicle or if a truck is approaching that is too high to enter the tunnel. Whether motorists pay attention to these sensors is a completely different story, however. It seems to me like a massive motorist education campaign would need to be undertaken to prepare drivers for interaction with these vehicles. And don't even get me started on pedestrian safety.

The vehicles can be guided by rails or by optical guidance using painted lines. However, optical guidance has run into problems in other applications, due to the paint being obscured by oil, dirt and weather-related fading, so I'm not sure I'd trust optical guidance to reliably guide vehicles of this size. Rail will probably need to be laid, and that's not cheap.

These vehicles are obviously going to be very heavy. Will the roadways - or at least the edges of them where the vehicle's wheels are located - need to be rebuilt in order to support the weight of these things? And if so, does that mean that underground utilities will need to be relocated?

The video suggests that the straddling bus can be parked anywhere along a road when it is not in use, so cars will pass under it and it will not impede the flow of traffic. But what about when the bus needs routine maintenance? I imagine there will still need to be maintenance and storage facilities built to support these vehicles.

I really can't speak to the cost savings this concept claims to produce relative to a traditional subway, given that the economics of infrastructure construction in the Peoples Republic of China are completely different than what I'm familiar with. But fully 90% cheaper than building a subway? Color me skeptical. As expensive as subways might be to build, they are at least a proven technology. This concept is not, and hidden or unforeseen costs are all but certain.

Anyway, the video claims that construction on this concept is set to begin in Beijing later this year. I'm very curious to see if this is true and, if so, what the results will be. If it actually gets built, and if it is successful, it is something that can be economically and politically implemented outside of the People's Republic of China?

The Infrastructurist has an image gallery of the proposed concept. The Transit Pass is skeptical. Stay tuned.

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