Sounds like you are a candidate for a hybrid. At one time, In addition to my road bike, I have a Trek 7.3FX - the tires are 700C and skinnier with less tread than your 820. They also come in more expensive version up to the very cashie 7.7. Check them out at trekbikes.com . They will be considerably lighter than the mountain bike you are currently riding. Also, find the bike paths, I hate traffic also. Should be some great paths in the Chicago area.