Where I live at least, the rush-hour traffic seems to be significantly less bad on Fridays. Is it because enough people simply take Fridays off? Or is it because people are just a bit more flexible on Fridays? The boss probably isn’t going to get really mad if you’re a little late on Friday morning, or if you leave a little early on Friday afternoon. So people are a little more relaxed about their commuting time on Fridays, and the times that people hit the road are probably spread out a bit more, which reduces the peak-hour crush.

I’m only guessing but I wonder if this principle could be applied to congestion pricing. Instead of charging a price for travelling during certain times, charge a price for flexibility (like airlines do). Say you allocate everyone a random time window in which they can travel for free during the rush-hour. Outside this window they can still travel but they have to pay, so those who need flexibility can pay for it. At the right price, enough people will choose to stick to their allocated time window, the random allocation might smooth the traffic flows enough to reduce congestion. I guess an experiment would be needed to test this and see whether it works and whether it’s more or less efficient than standard congestion pricing.