If you eliminate toll roads, then this may have the opposite affect as it makes travelling cheaper. Therefore more people will be able to use such roads and therefore it could increase the number of road users, instead of opting for alternative methods of travel.
A policy on turning of ones engine would be sufficient to prevent people sitting in car parks eating their food. It's not the drive throgh service that creates the problem, it's peoples lack of awareness.
I would suggest making it more beneficial to people to opt for cheaper to run cars. Tax incentives and cuts on more efficient cars, placing a higher rate of tax on SUV's, which are pointless in my opinion for the average person!
Not only is it the type of car that one drives, but also the way in which they drive it. Some kind of educational flyer or campaign etc... would be very beneficial in order to teach people how to get the most from their petrol.
I have seen recently that Honda has developed a Hydrogen powered car which will be leased to a minority of people in the coming years. perhaps this could be the revolution that we are waiting for, what it will do to the economy and political make up of the world, I dont know....