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I understand the intention here of reducing stop time at stoplights for cars, but I think this is a dangerous project. The word pedestrian, or bicycle does not

I understand the intention here of reducing stop time at stoplights for cars, but I think this is a dangerous project. The word pedestrian, or bicycle does not exist in this article whatsoever. Traffic lights are a flawed, but useful tool for traffic calming. If we optimize for reducing the amount of red lights cars will run into, this will fundamentally increase speeds on roads, and increased speeds, equals increase pedestrian, cycle, and car deaths. This is all conjecture, but it seems like the key indicator that Google is providing two cities is reduction in stop time. If that is their key metric, while also not looking at other things like bicycle stop time, or pedestrian wait time; we will be optimizing for average car speed indirectly. That is a bad thing inside of cities.

deleted 2y ago
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syrgian 2y ago
It seems to me that it would increase safety, but I guess only a simulation could truly tell. I understand your take, but I have a different one: most accidents happens when someone makes a mistake at stop light changes. Less cars stopping/starting at red lights seems less chances for accidents to me. Let's go with an absurd example: If you multiplied by 5 both the length of red and green stages, I would expect much less accidents per day, but it would obviously also be much more frustrating to move around (and possibly more accidents if the amount of infractions increase because of the frustration). If you divided them by 2, I would expect much more accidents of all kinds.
rossng 2y ago
Another obvious issue: you can make traffic flow faster by reducing the time allotted to pedestrians. This makes walking a worse and less dignified experience. So even more people decide to drive instead of walking. Result: more traffic, more emissions, worse city. The researchers would have to be very naive to omit this from their model, so I am going to assume that they did take it into account. But I agree - it's disturbing not to see it mentioned at all.

deleted 2y ago

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syrgian 2y ago

It seems to me that it would increase safety, but I guess only a simulation could truly tell. I understand your take, but I have a different one: most accidents happens when someone makes a mistake at stop light changes. Less cars stopping/starting at red lights seems less chances for accidents to me. Let's go with an absurd example: If you multiplied by 5 both the length of red and green stages, I would expect much less accidents per day, but it would obviously also be much more frustrating to move around (and possibly more accidents if the amount of infractions increase because of the frustration). If you divided them by 2, I would expect much more accidents of all kinds.

rossng 2y ago

Another obvious issue: you can make traffic flow faster by reducing the time allotted to pedestrians. This makes walking a worse and less dignified experience. So even more people decide to drive instead of walking. Result: more traffic, more emissions, worse city. The researchers would have to be very naive to omit this from their model, so I am going to assume that they did take it into account. But I agree - it's disturbing not to see it mentioned at all.