[llamaorama]

You guys clearly lack creativity. Worst case scenario, they could put up concrete jersey barriers around the space where its sides roll and/or make it run on tracks with double flanged wheels that "grab" the rail and would help prevent such a wreck. Also, the thing could have emergency ramps and a lift device for the disabled in case of an evacuation. It doesn't suffer from the same problem as monorails in this regard since by always requiring some bottom clearance near its sides you'd just work this stuff in and not worry about deploying ways down in an urban environment.

I guess the weak link would be in perpendicular crossings, though.

The benefit of this over an elevated rail line is that while the vehicles would be incredibly costly, a elevated right of way would be even more so.