It’s a bridge! It’s a bus! But is it real?

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ImageSince May, the Internet has been a-buzz with the “bridge bus”, a never-before-seen public transit contraption scheduled for a 186 km route pilot in Beijing later this year. The bus straddles existing roadway lanes, creating a moving tunnel-like effect for the vehicles underneath. The vehicle’s Shenzhen-based designers claim that the system can move up to 1,200 passengers at a time (300 per bus), without taking away from existing road space, while at the same time reducing fuel consumption (the bridge bus runs on electricity, partially supplied by solar panels), and at a lower cost than building a subway. A revolution!

I am a big fan of entrepreneurial innovation in transit. And when I see something truly innovative and different come out of one of the countries where we work, I get very excited! But there is something about this concept -- something that doesn’t seem quite right…


The Proposal

Detailed information about the project may be found here, including a video produced by company pioneering the concept:

The Questions

Mind you, I know nothing about this program other than what’s been flowing through the blog-o-sphere. But with my limited perspective, the bridge bus concept would seem to pose a few dilemmas:

1)      This sounds…expensive.

The bridge bus runs on tracks embedded into an existing road. Which means, to deploy the system, unlike a dedicated bus lane or bus rapid transit system, we still have to build tracks – just like we would for a light rail system. Except, these tracks may be more cumbersome, because anytime a city wants to do road or track maintenance, both the bus and the regular traffic systems would need to be shut down (with dedicated guideways, this is less likely). And to accommodate the vehicles’ unique elevation, we would have to build stations that far more elaborate than a typical light rail or streetcar station. In fact, every single station would be like building a pedestrian flyover, but at least five times bigger and with greater load factors -- and bridges are pricey (simple pedestrian bridges over major arterials can exceed USD 1.5 million each). 




For reference, here are some (unofficial) comparisons:



Bridge Bus

Diesel Articulated Beijing BRT*

4-Car Electric Light Rail

Electric Street Car

Vehicle Cost per Passenger

USD 6,666

USD 1,250



Maximum # passengers per vehicle





Estimated Construction Cost per km

USD 1.8 million

(w/out stations and w/out vehicles)

USD 2 million

(w/ stations)

USD 20 million

(w/ stations and vehicles)

USD 6 million

(w/ stations and vehicles)


Frequencies would be about the same, since all three options use dedicated lanes. But city could procure more buses and rail cars than bridge buses.

Same as typical bus in mixed traffic.

Affect on current road capacity

Same capacity, but lower travel speeds

One lane removed per direction

One lane removed per direction

Same capacity

 For alternatives, assumed existing roadway lane dedicated for transit.




2)      OMG! There is a giant bridge barreling towards me and I don’t know what to do!

Dangerous!! Caravan lines of cars traveling in tidy lanes may work in computer models...



Beijing Traffic Jam


Using feedback from proximity sensors, the bus emits a beeping noise to alert drivers that it is coming up behind them. But aside from the potentially annoying, extremely loud, constant noise that would have to emanate from these buses to alert drivers past their cell phones and mp3 players, can we be so sure everyone, including those new to a city, would know how to react?




3)      Does it really save travel time? Does it really benefit the environment?

It seems that since the bridge bus does not travel on elevated infrastructure, and since it doesn’t have a dedicated lane, unless complementary policies are made, the buses will still have to stop at intersections. And they will still have to stop at stations. And since only so many of these vehicles could be purchased (given their likely high cost relative to all other transit vehicles), it is unlikely that the frequency could be greater than, say, a light rail or bus rapid transit system.


System designers quote a litany of statistics, showing how environmentally friendly the system is, based on the fact that the system is electric (with some solar panels thrown in). It would seem worth mentioning that electric-based transit is a very old idea – seen still in operations today in subways, light rail, and streetcar systems. In short, and I am not sure, but it seems like there may be safer and less expensive means to acheive the same environmental benefit... 


4)      So what if it breaks?

Only one company in the world makes these vehicles today, and only one will make them for the foreseeable future. Without open bidding, it may be difficult for cities to keep costs down for procurement and maintenance, and increased risks are also posed – what if the firm that designed this proprietary system goes out of business? That said, every new mode of transport had to have a “first” – should this be a concern?


5)      Wait a minute -- where is this Beijing Mengtou District, anyway?

What makes the concept truly impressive – what has been the source of the buzz -- is that it actually will be piloted in Beijing. But to be clear, the pilot will be implemented in the Beijing Mengtou District – a sparsely populated, mountainous suburb of Beijing, with very little traffic compared to the city center. This seems like a smart choice for such a risky pilot, but at the same time, does not lend confidence that Beijing is taking the concept too seriously…which leads us to our final question --

Is it real? Can it be real?

The Big Picture

The most remarkable feature of the bridge bus is its speed of adoption. After being unvelied in May, it has been slated for a real-life, fully constructed pilot before the end of this year -- and not just in some remote province, but in China's shining capital city. The bus represents a let's go, learning-by-doing, almost cowboy style can-do spirit, racing innovation as quickly as possible into practice. 

The project poses a myriad of questions and challenges. And I wonder, in the haste to implement, was there a peer review or stakeholder consultation process, through which most of these concerns were raised and addressed? If so, what were the answers? And if not, since this is a pilot, should it matter? This certainly wouldn't be the first infrastructure project to have been quickly built without prolonged due process -- think of the legendary Jaime Lerner and his many achievements in Curitiba.  But then, the lack of  consultation and impact analyses would seem to pose fiscal and safety risks, and just as importantly, prevent good ideas for conceptual improvement from being heard (thinking of the lack of stakeholder inputs on the US's 1960s urban renewal craze -- whose aftermath we still struggle with today).

Moving On

Readers – please tell me what you know about this thing, and whether you think it will work! This October, I’ll be back in China and, while there, may try to do some additional detective work. Stay tuned…


Information about the bridge-bus used in this post has been culled from:





Images of bus from:


Photo of Beijing traffic from:

·         Edwards, David and Welch, Morgan. 3 July 2010. “Beijing: Officially Expensive…” The Beijinger.



Holly Krambeck

Senior Transport Economist

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