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No, I think you're talking about a situation where two cars are pulling up to an empty intersection simultaneously. That's a low-traffic situation. The problem

No, I think you're talking about a situation where two cars are pulling up to an empty intersection simultaneously. That's a low-traffic situation. The problem comes when you're at a 4-way stop and people are coming from every direction. Anyone who wants to go through the intersection needs the cars from at least two other directions to let them through. So you, as one person, waving them through is pointless because at least one other person would also have to independently decide to let them through as well. If that doesn't happen, then either the other car listens to you and goes through the intersection and crashes into the third person who didn't wave them through, or you and the other car both end up waiting when only one of you needs to be. Either way, you're being rude to the people behind you, whose trip you have lengthened by the same amount you might have shortened someone else's trip, all the while making the intersection less predictable. Of course, there's always a race condition and potential for deadlock when two cars arrive simultaneously at an empty intersection, and waving people through is a safe and necessary way to solve that. But that's not an issue here, because if an intersection already has cars waiting to go from all four directions, there's a defined order in which they take turns according to the rules.

lutorm 12y ago
At 4-way stops in heavy traffic, it's difficult at best to tell the order in which people should go. If there's more than one lane in each direction, it becomes practically impossible. Imho, 4-way stops are terrible no matter how you slice it: in heavy traffic they're really inefficient not to mention difficult to navigate, and should be replaced with a traffic light. In light traffic they're also inefficient, and should be replaced with a yield from the non-dominant direction. In Sweden the default rule at an unsigned intersection is that you yield to the right. This means there's a well-defined algorithm for conflict resolution without putting stop signs at every little intersection. Apparently the idea that you could possibly navigate an intersection without signage is absurd to Americans, though.
- HeyLaughingBoy 12y ago
  Actually I'm impressed at how people negotiate when the signs break down. A few days ago, the traffic signals at a major intersection (a heavily trafficked US route and a Minnesota route) on my way to work went completely dark, both roads normally having 55mph speed limits. The intersection had two lanes of traffic on each road plus left turn lanes. Somehow traffic kept flowing. Traffic slowed way down and there were a few hairy moments, but by and large people treated the lights out situation as a stop sign and responded appropriately.
jff 12y ago
> Of course, there's always a race condition and potential for deadlock when two cars arrive simultaneously at an empty intersection, and waving people through is a safe and necessary way to solve that. There are very clear right-of-way rules for this situation, and if both drivers can manage to remember those simple rules, no hand signals will be needed.
- rcthompson 12y ago
  It's not that simple. There are some situations where you wait, and some where you can go, and there is necessarily a threshold, a point of ambiguity, between them.

lutorm 12y ago

At 4-way stops in heavy traffic, it's difficult at best to tell the order in which people should go. If there's more than one lane in each direction, it becomes practically impossible. Imho, 4-way stops are terrible no matter how you slice it: in heavy traffic they're really inefficient not to mention difficult to navigate, and should be replaced with a traffic light. In light traffic they're also inefficient, and should be replaced with a yield from the non-dominant direction. In Sweden the default rule at an unsigned intersection is that you yield to the right. This means there's a well-defined algorithm for conflict resolution without putting stop signs at every little intersection. Apparently the idea that you could possibly navigate an intersection without signage is absurd to Americans, though.

HeyLaughingBoy 12y ago
Actually I'm impressed at how people negotiate when the signs break down. A few days ago, the traffic signals at a major intersection (a heavily trafficked US route and a Minnesota route) on my way to work went completely dark, both roads normally having 55mph speed limits. The intersection had two lanes of traffic on each road plus left turn lanes. Somehow traffic kept flowing. Traffic slowed way down and there were a few hairy moments, but by and large people treated the lights out situation as a stop sign and responded appropriately.

jff 12y ago

> Of course, there's always a race condition and potential for deadlock when two cars arrive simultaneously at an empty intersection, and waving people through is a safe and necessary way to solve that. There are very clear right-of-way rules for this situation, and if both drivers can manage to remember those simple rules, no hand signals will be needed.

rcthompson 12y ago
It's not that simple. There are some situations where you wait, and some where you can go, and there is necessarily a threshold, a point of ambiguity, between them.