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So a system that requires all vehicles on the road to have flawless sensor and communications systems can achieve some improvement over current-day technology (

So a system that requires all vehicles on the road to have flawless sensor and communications systems can achieve some improvement over current-day technology (from the paper, approximately a "doubling of capacity" for intersections with this implemented.) This is a profoundly uninteresting result, given the current-day technology in question is "a dozen lights attached to a timer." Add devices that are several orders of magnitude more expensive and yeah you'll get something better- that they only achieve a factor of two improvement (in theory!) reads as a stunning failure of autonomous vehicle technology to pull their weight in this regard. (Granted, more clever schemes might be produced that might get better results from this scenario- it's hard to prove that they can't be effective.) Better idea- instead of having the world pay for sensor/communication systems on every car, have the same sensor packages installed on the traffic lights so that they can operate in a smarter fashion. Orders of magnitude less expensive, and quite possibly as effective in reducing traffic backup.

jakecopp 9y ago
What I don't understand is why every traffic light doesn't have cameras and some image recognition/machine learning (whether local or remote) to improve the timing - it would be such a cheap and easy fix compared to putting a sensor in each car.
- tedmiston 9y ago
  A sensor itself isn't expensive but moving, storing, and processing all of that data to ultimately take action is. Let alone concerns with people about being recorded in public, even if red light cameras are permitted in some states today.
  - jakecopp 9y ago
    Even OpenCV running on a Raspberry Pi can pick out cars in a moving image - a bad offline solution (with a sensible fallback) would be better than a timer. On a large remote setup I think you are right though.
    - jakobegger 9y ago
      OpenCV on a Raspberry does not sound like something that is reliable and easy to deploy. It‘s a long way to go from something that you hack together in the living room to something you can deploy on hundreds of traffic lights, that works in every weather, that can easily be configured for different use cases, and that can be serviced by the technicians.
      - jakecopp 9y ago
        You are right. I'm trying to say I think the problem is development bound and not insurmountable (secure, reliable, good fallback to timer) rather than "moving, storing, and processing data" bound as per the parent comment.
        tedmiston 9y ago
        I agree with you that developing a prototype wouldn't be too hard. But actually rolling it out within a few cities (and getting cities to pay for it) are where I think the complexities lie. I think it's a social or bureaucratic problem more than a technical one.
      - halbritt 9y ago
        It can be: https://resin.io https://resin.io A Raspberry Pi is a surprisingly useful and cost effective device when it comes to IOT. Most industrially hardened devices of similar capacity cost a bit north of an order of magnitude more. There are really only a couple of things that would need to be addressed, a good weather-tight case that allowed for heat dissipation, decent storage (most microSD has a short lifespan), and a good 5v power supply. In many cases, designing a system that is cheap, expendable, and expected to fail is way less costly than the alternative.
        TFortunato 9y ago
        Sone of what your saying is kind of making the point of the parent though. Yes, you can make the software deployment go easier, and resin looks like an interesting project from that front. But that really is only a small part of the problen, and those hardware problems you described aren't trivial. The testing you described to convincingly show that your device can handle the environmental requirements isn't trivial. (And by environmental, I dont just mean weather, but also things like available power quality, vibration, etc.) These industrial devices aren't expensive just because the suppliers aren't aware of RasPi, or are looking to gouge you. Its because they put in a lot of work to qualify these devices for their intended conditions. The RasPi, hacked up solution might actually be the WAY more expensive option over it's lifetime, if I have to roll maintenance crews every couple of months to replace SD cards or fix a flaky connector. And god forbid our code hangs in a way that makes all of the lights at an intersection green. "Oh you have a way to prevent that? Prove it." Designed to fail works fine for microservices where I can spin up a new instance rapidly, but it isn't the best match for industrial or infrastructure in most cases. Apologies if I'm coming across overly snarky here. I genuinely love the RaspPi, and its got a great niche for prototyping, hacking up one-off projects, or even as the base for many types of connected projects. But I've also worked on industrial and infrastructure types of systems, and more than once I've seen someone say that they've got a cheaper solution to X, when really they've got something that may look cheaper if your only looking at upfront costs, but they are completely ignoring the lifetime costs of the solution.
  - maxander 9y ago
    A traffic light would only need to solve a much simpler problem than an autonomous car- after image-recognition, given the number of cars waiting/approaching at each direction, decide which lane(s) to give a green light to. Finding a reasonably optimal policy could be hard, yes, but once one is found that could be applied to all (or most) traffic lights, and it couldn't plausibly be more computationally intensive to run than the image-recognition step. Meanwhile, if conversation involves a plausible future where all/most vehicles (inevitably including police cars and other government-owned vehicles) are autonomous and have the same kind of sensors, its hard to imagine the anti-surveillance angle being a decisive factor. I'm not for pervasive surveillance, and perhaps the NSA will be nice and claim really convincingly that they can't access records from traffic lights... but that bird has flown, anyway.
- enobrev 9y ago
  Government owned cameras at every intersection doing [anything] recognition sounds horrible.
- jakobegger 9y ago
  Lots of traffic lights in my area already have sensors (induction loops to detect waiting cars or approaching bicycles, IR motion detectors to detect pedestrians). In some cases this is really useful (eg. a traffic light for a bike path does not need to switch very often in winter, so it only switches when a bike approaches) I think that the problem is that often there is too much traffic from all directions and even with all the sensors in the world the traffic light can‘t change that.
  - jakecopp 9y ago
    I believe the induction loops only sense if the first car is present. This is helpful, but can't detect the number of cars which I think is the next most important metric.
    - niftich 9y ago
      There's also an amusing "failure mode" of induction loops: impatient people pulling up further into an intersection -- for example, aiming for an opportunistic left turn -- and they move off of the loop. The lights cycle; the left turn green arrow which would give them an exclusive phase never materializes.
    - nordsieck 9y ago
      At busy intersections, there will typically be a loop at the 1st spot and a second loop further back - say, at the 5th spot. It's not perfect, but it's pretty good.
- Reason077 9y ago
  Many traffic lights do have cameras/sensors to detect waiting traffic and measure wait times. It's not always quite so simple as using ML to adjust light timing, however. In big cities, at least, traffic lights are sometimes deliberately intended to slow traffic down in order to reduce volumes and speeds on the street, or to reduce congestion elsewhere on connecting roads.
- niftich 9y ago
  As others are indicating, this is tech exists, and in some places it's widely deployed, where in some others it's nowhere to be found. I've seen them in several US cities and suburbs, in many states, usually along major arterials and covering the busiest intersections. Missouri Department of Transportation's St Louis District has one of the best FAQs [1] on this tech that shows how these cameras work: exactly as you'd suspect from some OpenCV proof-of-concept. The cameras are a more robust replacement of the in-pavement induction loops, which are much more widely deployed, but give you a subset of the information at a higher cost. [1] http://www.modot.org/stlouis/links/signalcameras.htm http://www.modot.org/stlouis/links/signalcameras.htm
- madeofpalk 9y ago
  Sydney actually developed an integrated traffic light system titled "Sydney Coordinated Adaptive Traffic System" (SCATS) which has been exported around the world. It adjusts timing of traffic light systems using a variety of sensors - if a bus is running late it will affect the phasing to give it more green lights to try and get it back on time. https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Traffic_System https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Tr...
  - jakecopp 9y ago
    I believe the only car sensor for SCATS is an inductive loop so it doesn't know the amount of backed up traffic, and it was developed in the 1970s and rolled out across Australia in the 80s - it's better than a timer but I don't think it should be what the world aspires to. That being said, I had some interesting conversations with a person who worked for Transport for NSW who said some of the signalling backend was recently improved to streamline future integration with self driving cars, I can't find a reference for this though.
- lobster_johnson 9y ago
  This is usually called adaptive traffic control, and has been implemented (minus machine learning, I'm guessing) in a bunch of places, including a part of New York City [1] and, more famously, Australia [2]. The latter system, pioneered by the city of Sydney, has been sold to other countries such as Singapore. Not sure how technologically interesting these systems are. The Sydney system was developed in the 1970s, but has been improved with more modern tech (such as cellular networking) since then. [1] http://www.nyc.gov/html/dot/html/pr2012/pr12_25.shtml http://www.nyc.gov/html/dot/html/pr2012/pr12_25.shtml [2] https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Traffic_System https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Tr...
- DrScump 9y ago
  Magnetic loop sensors in pavement have been used to recognize vehicles at intersections for decades.
peter_l_downs 9y ago
> that they only achieve a factor of two improvement (in theory!) reads as a stunning failure of autonomous vehicle technology to pull their weight in this regard. Sounds like a profoundly interesting result to me -- strong evidence that we'd need to look elsewhere to increase transit carrying capacity. Maybe AI cars can't reduce traffic that much afterall.
- labster 9y ago
  This, so much. I wonder how much time and grant money is wasted because people don't publish negative results.
revelation 9y ago
It's a profoundly uninteresting result because, you know, we can already build autonomous trains. If you restrict the environment to what works for autonomous cars, we could have had them centuries ago. They will probably run on rails and look a lot like trains, but there you go..
jayd16 9y ago
>Better idea- instead of having the world pay for sensor/communication systems on every car, have the same sensor packages installed on the traffic lights so that they can operate in a smarter fashion. Human drivers preclude such a system. The article actually is about replacing the intersection but you still need the self driving cars to actually perform the optimizations.
iambateman 9y ago
The Benz Patent Motorwagen had a top speed of 10 mph, roughly equivalent to a horse+carriage. It will take time to iterate to get to the 4x-10x improvements we all hope to see.

jakecopp 9y ago

What I don't understand is why every traffic light doesn't have cameras and some image recognition/machine learning (whether local or remote) to improve the timing - it would be such a cheap and easy fix compared to putting a sensor in each car.

tedmiston 9y ago
A sensor itself isn't expensive but moving, storing, and processing all of that data to ultimately take action is. Let alone concerns with people about being recorded in public, even if red light cameras are permitted in some states today.
- jakecopp 9y ago
  Even OpenCV running on a Raspberry Pi can pick out cars in a moving image - a bad offline solution (with a sensible fallback) would be better than a timer. On a large remote setup I think you are right though.
  - jakobegger 9y ago
    OpenCV on a Raspberry does not sound like something that is reliable and easy to deploy. It‘s a long way to go from something that you hack together in the living room to something you can deploy on hundreds of traffic lights, that works in every weather, that can easily be configured for different use cases, and that can be serviced by the technicians.
    - jakecopp 9y ago
      You are right. I'm trying to say I think the problem is development bound and not insurmountable (secure, reliable, good fallback to timer) rather than "moving, storing, and processing data" bound as per the parent comment.
      - tedmiston 9y ago
        I agree with you that developing a prototype wouldn't be too hard. But actually rolling it out within a few cities (and getting cities to pay for it) are where I think the complexities lie. I think it's a social or bureaucratic problem more than a technical one.
    - halbritt 9y ago
      It can be: https://resin.io https://resin.io A Raspberry Pi is a surprisingly useful and cost effective device when it comes to IOT. Most industrially hardened devices of similar capacity cost a bit north of an order of magnitude more. There are really only a couple of things that would need to be addressed, a good weather-tight case that allowed for heat dissipation, decent storage (most microSD has a short lifespan), and a good 5v power supply. In many cases, designing a system that is cheap, expendable, and expected to fail is way less costly than the alternative.
      - TFortunato 9y ago
        Sone of what your saying is kind of making the point of the parent though. Yes, you can make the software deployment go easier, and resin looks like an interesting project from that front. But that really is only a small part of the problen, and those hardware problems you described aren't trivial. The testing you described to convincingly show that your device can handle the environmental requirements isn't trivial. (And by environmental, I dont just mean weather, but also things like available power quality, vibration, etc.) These industrial devices aren't expensive just because the suppliers aren't aware of RasPi, or are looking to gouge you. Its because they put in a lot of work to qualify these devices for their intended conditions. The RasPi, hacked up solution might actually be the WAY more expensive option over it's lifetime, if I have to roll maintenance crews every couple of months to replace SD cards or fix a flaky connector. And god forbid our code hangs in a way that makes all of the lights at an intersection green. "Oh you have a way to prevent that? Prove it." Designed to fail works fine for microservices where I can spin up a new instance rapidly, but it isn't the best match for industrial or infrastructure in most cases. Apologies if I'm coming across overly snarky here. I genuinely love the RaspPi, and its got a great niche for prototyping, hacking up one-off projects, or even as the base for many types of connected projects. But I've also worked on industrial and infrastructure types of systems, and more than once I've seen someone say that they've got a cheaper solution to X, when really they've got something that may look cheaper if your only looking at upfront costs, but they are completely ignoring the lifetime costs of the solution.
- maxander 9y ago
  A traffic light would only need to solve a much simpler problem than an autonomous car- after image-recognition, given the number of cars waiting/approaching at each direction, decide which lane(s) to give a green light to. Finding a reasonably optimal policy could be hard, yes, but once one is found that could be applied to all (or most) traffic lights, and it couldn't plausibly be more computationally intensive to run than the image-recognition step. Meanwhile, if conversation involves a plausible future where all/most vehicles (inevitably including police cars and other government-owned vehicles) are autonomous and have the same kind of sensors, its hard to imagine the anti-surveillance angle being a decisive factor. I'm not for pervasive surveillance, and perhaps the NSA will be nice and claim really convincingly that they can't access records from traffic lights... but that bird has flown, anyway.
enobrev 9y ago
Government owned cameras at every intersection doing [anything] recognition sounds horrible.
jakobegger 9y ago
Lots of traffic lights in my area already have sensors (induction loops to detect waiting cars or approaching bicycles, IR motion detectors to detect pedestrians). In some cases this is really useful (eg. a traffic light for a bike path does not need to switch very often in winter, so it only switches when a bike approaches) I think that the problem is that often there is too much traffic from all directions and even with all the sensors in the world the traffic light can‘t change that.
- jakecopp 9y ago
  I believe the induction loops only sense if the first car is present. This is helpful, but can't detect the number of cars which I think is the next most important metric.
  - niftich 9y ago
    There's also an amusing "failure mode" of induction loops: impatient people pulling up further into an intersection -- for example, aiming for an opportunistic left turn -- and they move off of the loop. The lights cycle; the left turn green arrow which would give them an exclusive phase never materializes.
  - nordsieck 9y ago
    At busy intersections, there will typically be a loop at the 1st spot and a second loop further back - say, at the 5th spot. It's not perfect, but it's pretty good.
Reason077 9y ago
Many traffic lights do have cameras/sensors to detect waiting traffic and measure wait times. It's not always quite so simple as using ML to adjust light timing, however. In big cities, at least, traffic lights are sometimes deliberately intended to slow traffic down in order to reduce volumes and speeds on the street, or to reduce congestion elsewhere on connecting roads.
niftich 9y ago
As others are indicating, this is tech exists, and in some places it's widely deployed, where in some others it's nowhere to be found. I've seen them in several US cities and suburbs, in many states, usually along major arterials and covering the busiest intersections. Missouri Department of Transportation's St Louis District has one of the best FAQs [1] on this tech that shows how these cameras work: exactly as you'd suspect from some OpenCV proof-of-concept. The cameras are a more robust replacement of the in-pavement induction loops, which are much more widely deployed, but give you a subset of the information at a higher cost. [1] http://www.modot.org/stlouis/links/signalcameras.htm http://www.modot.org/stlouis/links/signalcameras.htm
madeofpalk 9y ago
Sydney actually developed an integrated traffic light system titled "Sydney Coordinated Adaptive Traffic System" (SCATS) which has been exported around the world. It adjusts timing of traffic light systems using a variety of sensors - if a bus is running late it will affect the phasing to give it more green lights to try and get it back on time. https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Traffic_System https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Tr...
- jakecopp 9y ago
  I believe the only car sensor for SCATS is an inductive loop so it doesn't know the amount of backed up traffic, and it was developed in the 1970s and rolled out across Australia in the 80s - it's better than a timer but I don't think it should be what the world aspires to. That being said, I had some interesting conversations with a person who worked for Transport for NSW who said some of the signalling backend was recently improved to streamline future integration with self driving cars, I can't find a reference for this though.
lobster_johnson 9y ago
This is usually called adaptive traffic control, and has been implemented (minus machine learning, I'm guessing) in a bunch of places, including a part of New York City [1] and, more famously, Australia [2]. The latter system, pioneered by the city of Sydney, has been sold to other countries such as Singapore. Not sure how technologically interesting these systems are. The Sydney system was developed in the 1970s, but has been improved with more modern tech (such as cellular networking) since then. [1] http://www.nyc.gov/html/dot/html/pr2012/pr12_25.shtml http://www.nyc.gov/html/dot/html/pr2012/pr12_25.shtml [2] https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Traffic_System https://en.wikipedia.org/wiki/Sydney_Coordinated_Adaptive_Tr...
DrScump 9y ago
Magnetic loop sensors in pavement have been used to recognize vehicles at intersections for decades.

peter_l_downs 9y ago

> that they only achieve a factor of two improvement (in theory!) reads as a stunning failure of autonomous vehicle technology to pull their weight in this regard. Sounds like a profoundly interesting result to me -- strong evidence that we'd need to look elsewhere to increase transit carrying capacity. Maybe AI cars can't reduce traffic that much afterall.

labster 9y ago
This, so much. I wonder how much time and grant money is wasted because people don't publish negative results.

revelation 9y ago

It's a profoundly uninteresting result because, you know, we can already build autonomous trains. If you restrict the environment to what works for autonomous cars, we could have had them centuries ago. They will probably run on rails and look a lot like trains, but there you go..

jayd16 9y ago

>Better idea- instead of having the world pay for sensor/communication systems on every car, have the same sensor packages installed on the traffic lights so that they can operate in a smarter fashion. Human drivers preclude such a system. The article actually is about replacing the intersection but you still need the self driving cars to actually perform the optimizations.

iambateman 9y ago

The Benz Patent Motorwagen had a top speed of 10 mph, roughly equivalent to a horse+carriage. It will take time to iterate to get to the 4x-10x improvements we all hope to see.