> Actuated signal control [...] inductive loop sensors embedded into the road surface
It blows my mind how many people don't realize that's what those circles near the stop bar of an intersection are for, and will then stop 3+ car lengths behind the stop bar, and then can't figure out why the light is never going green.
> two signals closely spaced in a row on a major roadway. If one signal gives a green but the next one doesn’t, cars can back up
This is a major problem at an intersection near me that I used to have to drive through frequently. Two intersections, only about 500 feet between them, and MOST traffic during rush out coming from just one of the directions, yet the lights were often exactly out of sync. The first light would be red while the next one was green. Then the first would go green while the other went red, and traffic would only move about 500 feet then stop for 2 minutes. The backup would last well over a mile.
> The obvious next step in efficiency is coordination of most or all the signals within a traffic network. This is the job of adaptive signal control technologies, or ASCT. [..] These types of systems can dramatically reduce congestion
My cynical ass would not be surprised at all if oil/gas companies were lobbying against ASCT because idling cars are buying more fuel. Wouldn't be too hard to convince people that an ASCT would cost too much to implement while not producing significant traffic benefits.
> This is a major problem at an intersection near me that I used to have to drive through frequently. Two intersections, only about 500 feet between them
In San Francisco (as well as other cities I've lived in) they put police in the middle of intersections during rush hour to guide traffic (i.e., stop cars before they drive into an intersection that they'll get stuck in the middle of). Seems woefully inefficient
Sohcahtoa82 · · focus · HN ↗
It blows my mind how many people don't realize that's what those circles near the stop bar of an intersection are for, and will then stop 3+ car lengths behind the stop bar, and then can't figure out why the light is never going green.
> two signals closely spaced in a row on a major roadway. If one signal gives a green but the next one doesn’t, cars can back up
This is a major problem at an intersection near me that I used to have to drive through frequently. Two intersections, only about 500 feet between them, and MOST traffic during rush out coming from just one of the directions, yet the lights were often exactly out of sync. The first light would be red while the next one was green. Then the first would go green while the other went red, and traffic would only move about 500 feet then stop for 2 minutes. The backup would last well over a mile.
> The obvious next step in efficiency is coordination of most or all the signals within a traffic network. This is the job of adaptive signal control technologies, or ASCT. [..] These types of systems can dramatically reduce congestion
My cynical ass would not be surprised at all if oil/gas companies were lobbying against ASCT because idling cars are buying more fuel. Wouldn't be too hard to convince people that an ASCT would cost too much to implement while not producing significant traffic benefits.
at1as · · focus · HN ↗
In San Francisco (as well as other cities I've lived in) they put police in the middle of intersections during rush hour to guide traffic (i.e., stop cars before they drive into an intersection that they'll get stuck in the middle of). Seems woefully inefficient
WalterBright · · focus · HN ↗
Imagine how much gas would be saved if the city spent a little effort on the traffic lights.
andrepd · · focus · HN ↗
account42 · · focus · HN ↗
It's not really saving gas if your alternative doesn't achieve even remotely the same thing.