BTW--If you want really quite roads, try riding at 3:30AM. I had to do that last week for work, over a 8.5 mile route through the middle of Greensboro and through downtown I saw a grand total of four moving motor vehicles, none overtaking me.
As a cyclist I have numerous reasons for enjoying summer even in the south. My main reason though is summer vacations. Not mine, the vacations everyone else is taking. Once Memorial Day passes there is a marked decline in motor traffic volume. This was VERY true when I lived outside the District of Columbia and is appearing to hold true here in Greensboro, NC. With the lighter traffic motorists generally become a bit more tolerant of delays (of course there are always exceptions) and are not inclined to "buzz" cyclists and make other less than safe manuvers to get around them. Most of my mileage accrues during the early hours of the day when it is relatively cool so when I am finishing up I am mixing it up with other commuters like myself.