That reminds me of an ironic discovery they had on the news a few years ago. They found that on (some?) motorways, the faster traffic tried to travel, the later the vehicles would arrive at the far end, or something along those lines.
It was to do with something akin to shock-waves travelling through the traffic when something slowed down ahead, and IIRC this turned out to be the cause of many pile-ups and areas of congestion and so on.
I'm not a driver (why am I reading this entry in fact? :D ), so there's probably others who know and can explain this thing a lot better than I, but I still found it pretty interesting so it stuck in my mind somewhat.
There was a Scientific American article a number of years ago (wish I had kept a copy) about density waves traveling through traffic. Above a certain traffic density, a slight slowdown can cause traffic to come to a halt some distance back. This is basically the fallacy of "rubbernecking" that you hear about on traffic reports all the time. As amusing as it is to believe that big traffic jams on the opposite side of the road from an accident are caused by idiots slowing down to 5mph to "take a look," they're actually caused by people slowing down a little bit when they see a problem ahead, but don't yet know if it affects them. (This is why there aren't rubbernecking delays when traffic is light.) Does anyone believe we'd be safer if people didn't slow down when they see trouble ahead?
Another interesting bit from the article is that density waves travel backward and forward from an incident. I've recognized this once I learned to look for it; people think they're out of the woods and try to speed up to cruising speed, but things haven't quite cleared out enough, so it jams up again. It can be pretty mysterious if you get onto the road after the incident, though; you keep hitting slowdowns, but never pass anything that has caused them.
I'm sure I kept a copy, but darned if I know which box in the basement it's in. If we're talking about the same article, the authors described their method of undoing stop-and-go jams, which sounded interesting, but where I usually encounter that sort of situation (I-495 and I-95) I don't have the loooong straight stretch of road in my rear view mirror on which to observe the results of what I'm doing, the way the authors did in the experiment they did.
(no subject)
It was to do with something akin to shock-waves travelling through the traffic when something slowed down ahead, and IIRC this turned out to be the cause of many pile-ups and areas of congestion and so on.
I'm not a driver (why am I reading this entry in fact? :D ), so there's probably others who know and can explain this thing a lot better than I, but I still found it pretty interesting so it stuck in my mind somewhat.
(no subject)
Another interesting bit from the article is that density waves travel backward and forward from an incident. I've recognized this once I learned to look for it; people think they're out of the woods and try to speed up to cruising speed, but things haven't quite cleared out enough, so it jams up again. It can be pretty mysterious if you get onto the road after the incident, though; you keep hitting slowdowns, but never pass anything that has caused them.
(no subject)
*chuckle* You might, I don't listen to 'em ;) (see "not a driver" disclaimer above)
*blink* Now that seems rather surprising! I wish you'd kept a copy even more now! :D
(no subject)