People slow down to enjoy a look at the wreckage on the other side of the divider.
Curiosity has the same effect as a bottle-neck.
Even the driver who, when he arrives at the site, is ten minutes behind schedule is likely to feel that he’s paid the price of admission and, though the highway is at last clear in front of him, will not resume speed until he’s had his look, too.
Eventually large numbers of commuters have spent an extra ten minutes driving for a ten-second look.
(Ironically, the wreckage may have been cleared away, but they spend their ten seconds looking for it, induced by the people ahead of them who seemed to be looking at something.)
What kind of a bargain is it?
A few of them, offered a speedy bypass, might have stayed in line out of curiosity; most of them, after years of driving, know that when they get there what they’re likely to see is worth about ten seconds’ driving time.
When they get to the scene the ten minutes’ delay is a sunk cost; their own sightseeing costs them only the ten seconds.
It also costs ten seconds apiece to the three score motorists crawling along behind them.
Everybody pays his ten minutes and gets his look.
But he pays ten seconds for his own look and nine minutes, fifty seconds for the curiosity of the drivers ahead of him.
It is a bad bargain.
More correctly, it is a bad result because there is no bargain.
As a collective body, the drivers might overwhelmingly vote to maintain speed, each foregoing a ten-second look and each saving himself ten minutes on the freeway.
Unorganized, they are at the mercy of a decentralized accounting system according to which no gawking driver suffers the losses that he imposes on the people behind him.
from "On the Ecology of Micromotives"
https://link.springer.com/chapter/10.1007/978-1-349-01977-9_2