The Numbers Guy from the Wall Street Journal sheds some light on the chances you're taking when you decide to leave a game early to beat traffic. I was at 4th and 26 and I'll always remember laughing about the people who we saw leave just before it happened. 

The bottom line is that "come from behind" victories rarely happen, but that's precisely why you have to stay until the end. When you pay for a ticket, part of the cost is directly related to the chance that you might see something historic and truly memorable. When you leave early to beat the traffic, you forfeit that chance. If every game was a blowout, tickets would be much less expensive than they currently are. 

I know people have other obligations that don't allow them to stay to the end of every game - but the bar should be set pretty high. If you add up all of the pleasure you get out of beating traffic, my guess is that it doesn't come close to those one or two great sports moments you will experience in your lifetime if you stay.