A larger vehicle full of passengers is often more efficient than a smaller one. Are we going to regulate minimum passengers per vehicle size? I'm not sure this

A larger vehicle full of passengers is often more efficient than a smaller one. Are we going to regulate minimum passengers per vehicle size? I'm not sure this proposal solves the intended problem in a meaningful way. I'd rather see hefty taxes on fuel. This might yield better incentives toward urbanization, alternative transportation, and mass-transportation infrastructure.