Regulation isn't an appropriate response. If taxi's are cheap to operate (hence ample supply but artificially limited) then personal vehicles are cheap as well. "Big fat lazy motherfuckers" will just buy their own vehicle and make an even larger mess.

Pardon my idealistic views, but it would be better to curb demand for taxis with: a. cheaper, more consistently on-time public transportation b. safer bike routes c. casual carpool programs

The real question is why you rather take a taxi than your local public transportation.