Yeah, here (http://www.youtube.com/watch?v=lhxVtUFZVzk) they claim 2x the efficiency of bicycling, thanks to aerodynamics. There are some serious logistical challenges - e.g. to address the problem of slow people & free riders you might have to detect and incentivize/reward contributing (human) power to the system.

But the low-weight, self-powered approach means it's probably the lowest-cost system to mount above the current din of street life, which could end up being a big benefit.

I'd file it under strange/interesting, rather than crazy/ridiculous