I talked to a robotics expert two weekends ago who predicted 10 years for Google's lobbying efforts in Nevada to succeed. I figured optimistically it would be a few years. I'm also surprised. +1 for rational lawmakers.
Someone had to go first. I would have expected some island to do it, like Isle of man. But why not Nevada. That does not mean that the lawmakers are particularly rational, just that they see a technology they like, or maybe they count it under good PR for the state.
http://blogs.forbes.com/alexknapp/2011/06/22/nevada-passes-law-authorizing-driverless-cars/
http://news.ycombinator.com/item?id=2688424