What are your thoughts on taxing people on miles traveled?

It's called the law of unintended consequences. It also applies to taxation. Liberals think raising tax rates, etc will bring in more money. History shows it doesn't. People's behaviour is not static. When taxed more, they will work less, put money in unproductive places, cheat more, stop spending, stop hiring, etc. Of course, they never learn from this. And you know the definition of insanity...when you keep doing the same things expecting a different outcome...