3 ms·

Yeah it's called a traffic jam. As the total number of cars on the road per unit of distance increases, the speed at which those cars can travel decreases. It's

Yeah it's called a traffic jam. As the total number of cars on the road per unit of distance increases, the speed at which those cars can travel decreases. It's not linear of course but, well, I think you get the picture.

mikeash 14y ago
As you add cars to a road, the throughput in terms of the number of people or cars per minute first increases. This should be pretty obvious: as you add cars to a nearly empty road, more people use it, but they all go just as fast as before. As you continue to add cars, you reach a point where cars start to slow down, but throughput continues to go up. Once you reach a certain point, people begin to drive slower due to congestion. But at low levels, this is offset by the additional number of people using the road, resulting in greater total throughput. Past that point, you reach another point where adding more cars does not increase throughput, as the added cars are balanced by the slowing of traffic as a whole. Beyond this point, adding more cars reduces the throughput of the road. Take this to the extreme, and you have a giant parking lot with people gradually inching forward, and people/cars per minute excruciatingly low. No sources, but I'd think this is all fairly obvious.
- thaumasiotes 14y ago
  This is fair. I would submit that there's a strong argument that, when the total supply of sheep goes up, everyone benefits. I don't think that's true of road throughput; that just benefits the people who are still on the road after you've put up the barrier to entry. I don't see that there's any sort of failure involved in the phenomenon of traffic jams -- I've "happily" sat in stop-and-stop traffic because it's still better than my alternatives. Participate and pay the cost of annoyance due to congestion, or don't and don't. You're on thin ground saying "you need to get off the road, so that it will function better for me".
  - mikeash 14y ago
    When everybody tries to crowd onto the highway, everybody slows down. Beyond a certain point, throttling usage actually makes everybody get to their destination faster. Imagine a roadway with some kind of nasty merge which gets severely jammed up if there are too many cars. If ten cars all try to go through at once, everybody could be stuck for quite a while. If you throttle them so they go through one by one, everyone gets to their destination faster. The same thing can apply to real roads on a larger scale.

mikeash 14y ago

As you add cars to a road, the throughput in terms of the number of people or cars per minute first increases. This should be pretty obvious: as you add cars to a nearly empty road, more people use it, but they all go just as fast as before. As you continue to add cars, you reach a point where cars start to slow down, but throughput continues to go up. Once you reach a certain point, people begin to drive slower due to congestion. But at low levels, this is offset by the additional number of people using the road, resulting in greater total throughput. Past that point, you reach another point where adding more cars does not increase throughput, as the added cars are balanced by the slowing of traffic as a whole. Beyond this point, adding more cars reduces the throughput of the road. Take this to the extreme, and you have a giant parking lot with people gradually inching forward, and people/cars per minute excruciatingly low. No sources, but I'd think this is all fairly obvious.

thaumasiotes 14y ago
This is fair. I would submit that there's a strong argument that, when the total supply of sheep goes up, everyone benefits. I don't think that's true of road throughput; that just benefits the people who are still on the road after you've put up the barrier to entry. I don't see that there's any sort of failure involved in the phenomenon of traffic jams -- I've "happily" sat in stop-and-stop traffic because it's still better than my alternatives. Participate and pay the cost of annoyance due to congestion, or don't and don't. You're on thin ground saying "you need to get off the road, so that it will function better for me".
- mikeash 14y ago
  When everybody tries to crowd onto the highway, everybody slows down. Beyond a certain point, throttling usage actually makes everybody get to their destination faster. Imagine a roadway with some kind of nasty merge which gets severely jammed up if there are too many cars. If ten cars all try to go through at once, everybody could be stuck for quite a while. If you throttle them so they go through one by one, everyone gets to their destination faster. The same thing can apply to real roads on a larger scale.