Flying down the road

Doesn't it seem like traffic patterns should be consistent? That is, shouldn't the commute in to work at the same time each day present the same driving conditions as long as the weather doesn't interfere?

My usual habit is to drive over I-93 before joining the vehicles on that road. On most mornings, my view is of a sea of brake lights or of slowly moving vehicles. In that case, I continue my commute using surface streets. Today was a different story; in spite of the every 10 minutes traffic report on one of the local radio stations informing me that I-93 was moving very slowly, I could see more road surface than vehicles and the cars were just flying.

Yes, my car & I did hop onto I-93 for a quicker than usual commute to work...