Certain sized and format cars should be taxed off city streets.
Family cars should revert to Sedans and Station Sedans. SUV/4x4 and Trucks (like) should be for outer regions and not family shopping trolleys.

Easy to implement, if your post code is inner city/suburbs tax the arse off them.

Ever really looks outside a school at drop off or pick up times? Insane...

Regards, Smooth