I commute in Chicago, where the roads are good but my route has a lot of glass, sometimes gravel if they're doing construction, and other various things in the bike lane. I ride my Trek 1200 road bike with 700x25 tires. I have continental ultragator skins on the front tire and michelin erilium on the rear. The erilium has a kevlar tread, which after 3 flats in a week I was all over that I've had good luck with them so far. I've ridden in rain also, and my traction was still good. I don't think you need knobby or wider tires for what you're going to be riding on persay.
"Only the meek get pinched, the bold survive"