Like all "economically sound" ideas, people fuck it up. To the drivers, its one more reminder of a government taxing you on a day to day basis, locking up the roads taxes paid for, for another series of taxes.

Chicago is the poster child here. Constant rate hikes. Diverted funds meant to maintain the roads going elsewhere. "Temporary" tolls that become "permanent", etc.

It's bad, stop the madness.