This idea of only one kind of way of proving one's identity is definitely not thought out. That said, I was curious what Canada does and found this:
http://www.elections.ca/content.aspx...dex&lang=e#one
What's interesting is the 2nd option if you can't meet the first. I've never had a driver's license (I've lived most of my life in cities where public transit was useful) and used the 2nd option all my life. It even includes options for the homeless identify themselves so they can vote.