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It's sort of the reverse, in a sense. If drivers adhered strictly to yield signs, those getting onto the highway would wait until there was a space in traffic.

It's sort of the reverse, in a sense. If drivers adhered strictly to yield signs, those getting onto the highway would wait until there was a space in traffic. There would be times when you could not get on to the highway at all, when traffic was heavy but not so heavy that it slowed. To solve this (again, with strictly following RoW), you would have to either slow speeds on the highway or put stop lights on the highway to let mergers enter the roadway. This doesn't happen because everyone understands that those merging onto the highway are moving fast and running out of space, and prudence dictates that you slow down to make space, rather than finding out if you're driving next to someone who will crash into you. At the far end of the spectrum from that situation, you have people waiting forever to cross, in a marked crossing where they have right of way, because they're stopped (the status quo supports them not going) and they stand to die if the driver doesn't yield properly. Fast unlimited-access roads are somewhere in the middle: the mergers don't have the initiative, but the suffering is more evenly distributed in the case of a crash, so the passing drivers are perhaps more prepared to slam on brakes. The on-ramp meters provide the service of prioritizing drivers from distant suburbs or out of town at the expense of those who dwell in nearer suburbs. To put a different spin on it, they slightly disincentivize short trips on highways.

seadan83 2y ago
I have trouble agreeing. > There would be times when you could not get on to the highway at all, when traffic was heavy but not so heavy that it slowed. The flowing traffic makes space for the merging traffic, which also takes up any existing gaps. The merging traffic ideally zipper merges at traffic speed. Traffic speed is correlated to gaps between cars. If merging gets tight, gap size is small, traffic is therefore going slower. If merging is impossible, then gap size is tiny, traffic speed is approaching zero, and both the onramp and highway are a traffic jam. It is the accumulation of new traffic that slows traffic speed. I think you are implying traffic speed remains a fixed constant and merging traffic just waits. Instead there is an interplay. Which comes to onramp lights. That is just a rate limiter to avoid the highway from going into an extreme bottleneck. The highway capacity is the bottleneck, so adding more traffic to it freely makes it exponentially worse. It is not at all about incentives but preservation of traffic flow. The idea of prioritizing distant suburbs falls a bit flat when considering the evening counter commute. The idea does hold somewhat for morning rush hour as on ramp meters do prioritize the speed of existing traffic. Regardless, the rate limiting is the purpose. Though, why are we talking about on ramp meters when the article is not about on ramp meters? > This doesn't happen because everyone understands that those merging onto the highway are moving fast and running out of space, and prudence dictates that you slow down to make space Merging traffic should be matching, not exceeding traffic speed. Existing traffic should _speed up_ to facilitate merging. The merging cars merge behind, not in front when cars are side by side. If a merging car does not get space, then they either slow, stop, or shoulder drive. A person might slow to facilitate a merging car that is well ahead of them. Generally that right hand lane should start opening gaps between every car to facilitate a zipper merge. If side by side, the traffic that has space, the existing traffic, should speed up to make space behind and to maintain traffic speeds. If they can't speed up, then there is overall congestion, gap size shrinks and traffic speed slows..

seadan83 2y ago

I have trouble agreeing. > There would be times when you could not get on to the highway at all, when traffic was heavy but not so heavy that it slowed. The flowing traffic makes space for the merging traffic, which also takes up any existing gaps. The merging traffic ideally zipper merges at traffic speed. Traffic speed is correlated to gaps between cars. If merging gets tight, gap size is small, traffic is therefore going slower. If merging is impossible, then gap size is tiny, traffic speed is approaching zero, and both the onramp and highway are a traffic jam. It is the accumulation of new traffic that slows traffic speed. I think you are implying traffic speed remains a fixed constant and merging traffic just waits. Instead there is an interplay. Which comes to onramp lights. That is just a rate limiter to avoid the highway from going into an extreme bottleneck. The highway capacity is the bottleneck, so adding more traffic to it freely makes it exponentially worse. It is not at all about incentives but preservation of traffic flow. The idea of prioritizing distant suburbs falls a bit flat when considering the evening counter commute. The idea does hold somewhat for morning rush hour as on ramp meters do prioritize the speed of existing traffic. Regardless, the rate limiting is the purpose. Though, why are we talking about on ramp meters when the article is not about on ramp meters? > This doesn't happen because everyone understands that those merging onto the highway are moving fast and running out of space, and prudence dictates that you slow down to make space Merging traffic should be matching, not exceeding traffic speed. Existing traffic should _speed up_ to facilitate merging. The merging cars merge behind, not in front when cars are side by side. If a merging car does not get space, then they either slow, stop, or shoulder drive. A person might slow to facilitate a merging car that is well ahead of them. Generally that right hand lane should start opening gaps between every car to facilitate a zipper merge. If side by side, the traffic that has space, the existing traffic, should speed up to make space behind and to maintain traffic speeds. If they can't speed up, then there is overall congestion, gap size shrinks and traffic speed slows..