I don't know about other tourists, but as a tourist myself, I like to visit cities that are clean and where I can easily get around using public transit. If I have to drive everywhere and there's lots of pollution, I pick someplace better to spend my time and money. In fact, the last thing I want to do in a foreign country is deal with driving a car: the traffic rules are all different (esp. in LHD countries), the customs different, and there's the question of liability. I don't even like touring American cities because of this (combined with the public transit being so awful), even though I live in this country; I'd rather go to Asia or western Europe where the public transit is excellent.