2 ms·

> I guess these people never heard of common techniques to detect vehicles - in surface wire loops to detect inductance changes from a car or bicycle, and camer

> I guess these people never heard of common techniques to detect vehicles - in surface wire loops to detect inductance changes from a car or bicycle, and cameras. They explicitly addressed exactly those two things in the article: "One early idea was to place a magnetic coil under the asphalt surface of a road to detect the approach of vehicles along a single route to an intersection and then adjust the duration of the green and red phases accordingly. Similarly, cameras placed at intersections can be used to count the vehicles in each approach and compute how best to time the lights at an intersection. But both technologies are expensive to install and maintain and therefore only a few intersections have been fitted out with them."

InclinedPlane 8y ago
> "One early idea was to place a magnetic coil under the asphalt surface of a road to detect the approach of vehicles along a single route to an intersection and then adjust the duration of the green and red phases accordingly." Huh? This is already common practice, why is this "an idea"?
- adrianmonk 8y ago
  I think the main difference with their solution is that, since vehicles carry the equipment, 100% of intersections would be covered. Some cities have synchronized lights, but as far as I know, it is only at key intersections. Presumably, the increased efficiency comes from shaving off time at every intersection on your entire trip. Seems like they'd also get more data (number of cars, individual positions and headings) and may be able to do something smarter with additional data.
  - takk309 8y ago
    Using existing sensor to collect more data is an ongoing challenge for many municipalities. There is an add on module for signal controllers that can be used to count vehicles and depending on the detection type (video, inductive loop, or microwave) the counts can distinguish vehicle type and users such as car vs bicycle.
toast0 8y ago
Yeah... they put that all the way at the end though, after they said that the design had hardly changed. It's also not clear to me that adding a module to every car, plus adding modules for the traffic controllers at every intersection is less expensive than installing modules and detectors at every intersection for existing methods.

InclinedPlane 8y ago

> "One early idea was to place a magnetic coil under the asphalt surface of a road to detect the approach of vehicles along a single route to an intersection and then adjust the duration of the green and red phases accordingly." Huh? This is already common practice, why is this "an idea"?

adrianmonk 8y ago
I think the main difference with their solution is that, since vehicles carry the equipment, 100% of intersections would be covered. Some cities have synchronized lights, but as far as I know, it is only at key intersections. Presumably, the increased efficiency comes from shaving off time at every intersection on your entire trip. Seems like they'd also get more data (number of cars, individual positions and headings) and may be able to do something smarter with additional data.
- takk309 8y ago
  Using existing sensor to collect more data is an ongoing challenge for many municipalities. There is an add on module for signal controllers that can be used to count vehicles and depending on the detection type (video, inductive loop, or microwave) the counts can distinguish vehicle type and users such as car vs bicycle.

toast0 8y ago

Yeah... they put that all the way at the end though, after they said that the design had hardly changed. It's also not clear to me that adding a module to every car, plus adding modules for the traffic controllers at every intersection is less expensive than installing modules and detectors at every intersection for existing methods.