well... i live in vegas. there's streets that i ride often, and streets that i try to stay off of. there's certain routes that i -usually- take to get to certain places. sometimes i'm feeling adventurous and change it up a bit... there's not many hills, unless you're going from one side of town to the other (then it's usually either a nice ride down or climbing up). snow has existed here maybe 2 times in my life and rain is not an everyday issue so i really don't have to worry about that too much.
i ride carefully and am constantly looking behind me (sux). but oh well.