During my commute I've noticed the most traffic on Wednesdays, even during the summer. I am thinking that a lot of people take Fridays off at least sometime rather than a long vacation and a lot of college classes don't include Fridays too.

For the same reason, Mondays haven't been that bad, building into Tuesdays and then receding on Thursdays.

So in other words, we all work at least one day a week - Wednesday!