Traffic Waves: Sometimes one driver can vastly improve traffic (1998) | Hacker News Reader

Traffic Waves: Sometimes one driver can vastly improve traffic (1998)

trafficwaves.org

15 pointsarmenarmen10 comments

Coming from Europe, I've noticed the jams here (Bay Area) are worse. Mostly, because there are way more cars. But I think it's also because people use less motor brake here (due to almost everyone driving automatic), and tend to stomp on the brakes, almost at the end, instead of slowing down earlier.

The annoying thing about this is that this article is quite old now and nothing in it was new when it was first written yet roads are still designed in ways that promote the faulty competitive behaviour.

By the way, I'm not arguing that there is anything wrong with the article, it's good, well written and nicely argued.

Sitting on one of these roads, there is sufficient information the vast majority of the time. If you see more than one pair of brake lights ahead, then back off.

People seem to default to trying to minimize instantaneous distance from the destination rather than realizing that this does not sum to an optimum.

There is another type of jam which is stop light jams which is caused by people accelerating to slowly and taking up to much space between cars.

The same behavior that reduces stress on the high way can in that case actually increase stress on smaller roads.

Some stop lights are really regulators - they reduce flow to another larger artery. For those, no behavior will improve throughput.

People going too slowly is not going to necessarily have a negative impact on throughput. It can - there are sets of roads that just are this way ( what you refer to as smaller roads ).

I see at least three run stoplights a week, so I'm more careful about starting than I used to be.

It seems to me like the article has it backwards: a single driver can mess up traffic for many people. I see nothing here to support the premise in the title.

You have to read the next article (it's the link at the bottom), which then describes in detail how one driver can indeed remove traffic jams. The first article explains how traffic jams form, so you can understand in the second article why a certain behaviour fixes the problem.

I always assumed it was just best practice to not drive up anyone's rear end due to the issue of stopping distance. I never thought about it as regulating traffic flow.

The TL;DR of that is: Something that is oscillating can be damped.

This is the bullwhip effect. A common issue in a supply chain. It's a timing and lack of information issue.

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