Repeal the car road fund licence based upon CO2 emmissions.
Instead of targetting the users change the rules to target the producers. I cannot affect the emmissions from my car, I can only buy something unsuitable. Make the suppliers build lower emmission cars, set limits and dates.
Oh, and whilst you're at it think more radically and support Hydrogen powered fuel cells. Only H2O as emmissions and the fuel source totally under scrutiniy and control.
Why is this idea important?
CO2 emmissions need to be reduced, but public transport is unreliable, unavailable, expensive, overcrowded and dirty.
We cannot expand the current public transport network and the oil supply is expected ( so I have read) to run out by 2020. We're wasting time and valuable resources chasing cobwebs. Be more positive and let's have a Government capable of grasping the nettle.
We will be back in the medieval times if we do not.