Think about it

There would suddenly be motivation to fix America's terrible infrastructure and improve public transit which in turn would:

• Reduce air pollution dramatically
• Reduce a primary source of environmentally destructive suburbanization
• Reduce a primary cause of megafauna extinction
• Reduce a primary cause of the urban heat island effect
• Eliminate the primary cause of death for children 18 and under
• Reduce the population of some of the worst human beings on earth (they all seem to love driving)

Caveats: There would need to be some exceptions for shipping, taxi drivers, etc which might be hard to enforce.