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Traffic-Flow Algorithm Can Reduce Fuel Consumption

Posted by timothy on from the what-could-possibly-go-wrong dept.

thecarchik writes "New projects from German automakers Audi and BMW promise to ease congestion simply by looking at traffic signals and driving style, in an effort to smooth the flow of traffic. Through a test course in Munich, vehicles were able to post phenomenal fuel efficiency gains simply by adjusting the timing of traffic lights depending on traffic volume — to whatever speed provides a so-called 'green wave' of four or more synchronized signals."

31 of 328 comments (clear)

  1. It astounds me by skelterjohn · · Score: 5, Insightful

    That this isn't done everywhere. With all the red light cameras everywhere (for safety), you'd think they could put a few out there that would make it so I don't spend 3 minutes every morning staring at an empty intersection.

    1. Re:It astounds me by Garble+Snarky · · Score: 4, Informative

      Traffic timings don't even need to rely on cameras, they frequently take input from the inductive sensors (even more ubiquitous than cameras) in all four streets on the intersection.

    2. Re:It astounds me by NeutronCowboy · · Score: 5, Interesting

      Not only is it astounding that this isn't done, it's old hat. Where I grew up, the main arteries were all set up so that if you traveled at the speed limit, you'd hit all green lights in one direction in the morning, and all green lights going the other direction in the evening. It saved gas, dramatically reduced average travel times and kept everyone going at the speed limit.

      Instead, the main arteries where I live now are all set up to turn red when a car triggers a sensor on a cross street. The end result of that is that a 5 lane thoroughfare stops 15 cars every 50-100 yards because one care on a tiny side street is making a right turn onto the thoroughfare. A 2 mile drive can easily take 5-10 minutes with no traffic, just because the lights are setup so stupidly. And god help us if there's traffic (like, say on Black Friday or something like that): going half a mile to get on the freeway easily takes me 15 minutes, just because there's a light every 50 yards, they're not coordinated, and only 2-3 cars are actually able to cross the intersection at a time.

      I'm always wondering if I should go to the city council meeting and ask why they're supporting terrorists with this inane system. The loss in gas mileage is atrocious, and the reason for it is just plain stupidity.

      --
      Those who can, do. Those who can't, sue.
    3. Re:It astounds me by gront · · Score: 3, Interesting

      Lights are intentionally mis-timed for safety. During rush-hour around here, you can breeze past most lights, always catching the green. Once rush hour passes, the lights are set so you hit every single frickin' light and can't catch a green. Forces everyone to slow down, consume gas, but hey... think of the children!

    4. Re:It astounds me by ktappe · · Score: 3, Insightful

      I'm always wondering if I should go to the city council meeting and ask why they're supporting terrorists with this inane system. The loss in gas mileage is atrocious, and the reason for it is just plain stupidity.

      Seems to me the reasons for stupidly-timed lights is threefold:
      1) Lowball bids from traffic light installers. To keep their bids low, a simple timer is way cheaper than a smart computer.
      2) Politicians who pull strings so their development's side-road gets priority over the main thoroughfare.
      3) Citizens like you and me who are too busy to attend council meetings and object.

      --
      "We can categorically state we have not released man-eating badgers into the area." - UK military spokesman, July 2007
    5. Re:It astounds me by Anonymous Coward · · Score: 5, Interesting

      Which inductive sensors suck hard for cyclists. I frequently go grocery shopping early in the morning or late at night when there's practically no traffic -- wanna make a left turn? Your choice: sit there for upwards of 5 minutes waiting for a cager to come trip the light (and then they have to wait for you to get through the intersection, a delay I'm sure they appreciate), or disregard the signal (yep, that's an infraction -- being on a bicycle gives me no immunity to laws, just to sensord) and turn when it's safe, without causing grief for others. I always come to a full stop, then turn left when there's no traffic, just to demonstrate a level of caution should that light be under observation, but I'd almost invariably be clear blowing straight through.

      Fortunately, one light along the way has cameras, NOT to ticket unwary marks for racing a short yellow, but to control the intersection. Car pulls up? you get a green in a few seconds, just like the loop sensors. Bike pulls up? you ALSO get a green, although the same delay means it'll be green before you get there, and you get just enough time to make it through before yellow. I wish more lights were set up this way.

      Besides, for the purpose of maintaining a green wave at traffic speed, I suspect cameras are the better oiption, as you can use the camera of the intersection you're controlling, whereas the induction sensors are usually too close (won't show the wave until the lead vehicles are practically stopped), and you'd need to use the sensors from the previous intersection.

    6. Re:It astounds me by yotto · · Score: 4, Funny

      U-Turns aren't legal here, but I frequently turn right, then turn around in a driveway or parking lot, and still get back to the intersection in plenty of time to beat the light change.

      However, this is the driving equivalent of a programming kludge and doesn't fix the actual problem that the lights are set up stupidly.

      Did I just make a computer analogy to better explain something about cars?

      --
      Pulp Audio Weekly - Geek News and Reviews
    7. Re:It astounds me by Dare+nMc · · Score: 3, Insightful

      most of the inductive sensors I have experienced are at the intersection, so you have stopped before they work, thus saving no fuel. They also pick up a single car and only optimize for that one car, and usually only on the lessor used roads, paying no heed to what they are stopping, and for how many. IE the ones I use see a single car (wanting to make a right turn 90% of the time) from a 30 mph lane turning on to a 65 mph highway, and the light will stop a string of a dozen cars going 70. With A very smart camera it would be possible to picking up how many cars, trucks, and where is the next opening. Need dozens of loop sensors to do that.

      It would be a huge fuel savings if the lights know for example we have 3 loaded semi-trucks and 5 cars going 70 wait for them to pass and make the slow moving car wait longer. It would also be extremely helpful if we could get info sharing on light timing into something like the google map android phone applications, so that it could tell me to adjust speeds to hit lights, or to create a gap, or turn earlier to avoid a string of bad lights (or join a small group of cars...)

    8. Re:It astounds me by Anonymous+Struct · · Score: 3, Insightful

      I'd add a fourth possible reason, though: I think traffic control may be a little more complicated than we give it credit for. When there's one main road and everybody's on it, it makes sense to try to get long synchronized trains of traffic flowing through green lights. But as soon as you start to get more than one big road, you have to also think about how much traffic you're allowing into different parts of the city at once. If you look at traffic management as a big picture, then giving people green lights doesn't get them off your plate, it just moves them to another part of your grid. If you're stuck at a red light for 30 seconds too long and nobody seems to be going, consider that it may be because 3 miles up the road, that bubble is intended to absorb some traffic from another busy intersection.

      Or, as you say, it could just be cheap systems.

    9. Re:It astounds me by no1home · · Score: 4, Informative

      As a motorcyclist, I run into this some as well, though they have improved greatly (or it's because I have a bigger bike now). I have been pulled over once in my hometown for running a red. I explained to the nice officer (she was hot too, BTW) that I had waited through three cycles of the lights and never was given a green for my left turn, so, when it was clearly safe, I went. She let me go. Now, I hear rumor this is legal, but don't depend on it. It might not be for your jurisdiction (or even mine). However, it might be legal simply based on the idea that the signal is malfunctioning and you must therefore take matters into your own hands. You can solve your problem with a rare-earth magnet stuck to the bottom bracket of your bicycle. I know some bikers who use it and it has helped them.

      --
      I hope this comment is well received... I could have moderated instead!

      Persecutors will be violated!
    10. Re:It astounds me by pearl298 · · Score: 3, Informative

      In Scottsdale Az the lights are deliberately set to stop you at EVERY intersection! WHY you ask? According to the chief traffic engineer "So you will be "encouraged" to stop and shop at the local businesses along the way!!" Yes I actually heard this from his lips! Although his head did seem a little strange from a bad case of "recto-cranial inversion". I NEVER shop in Scottsdale because of this!

    11. Re:It astounds me by veganboyjosh · · Score: 3, Interesting

      In most places, provided you do wait for the numerous cycles of light changes, and it never does change for your motorcycle or bicycle, you are legally allowed to treat the signal as malfunctioning. It's not registering a legal vehicle, therefore it is malfunctioning. Treat it like a stop sign, and go through the intersection when it's safe. I am not a lawyer. I do work in/with bicycle advocacy and have heard this from several independent sources.

    12. Re:It astounds me by pcolaman · · Score: 3, Funny

      So what happened? Did the light ever change?

    13. Re:It astounds me by ztransform · · Score: 4, Interesting

      U-Turns aren't legal here, but I frequently turn right, then turn around in a driveway or parking lot, and still get back to the intersection in plenty of time to beat the light change.

      You have to love Australia. That particular manoeuvre is illegal there. Also illegal is exiting a roundabout from the same road you entered.

      Truth is everybody in Australia is a criminal. You just have to wait until some prosecuting authority thinks it's your turn and they find the rule to nail you with.

    14. Re:It astounds me by daid303 · · Score: 3, Interesting

      Don't complain at slashdot, complain at the city council. It is possible to detect cyclists with inductive sensors, but they are not installed 99% of the time due to the extra costs. I work at a company that supplies traffic-lights, and I found out recently that one of the lights I used to cycle past as a kid was produced by us. And it had no problems detecting me, giving me green light without stopping.

      Also, you don't get a lot of green as a cyclist because cyclist green is 'expensive' in time. They have to set the clearance time to the slowest cyclist. So all that time they cannot give green to any lights that would cross your cycle route, which impacts the flow of traffic a lot. But don't fear yellow lights if you have enough speed, you have plenty time. And if you know the intersection a bit then the beginning of red can also be safe for you. But you might need to do some explaining to the local cop from time to time.

      And as last, green waves are not controlled by cameras or induction sensors but by strict timing and communication between the intersections. The first intersection just signals the rest that a group of cars is coming so the rest can prepare for that. Or, in cheap cases, the intersections just run on fixed programs designed so that the green wave always happens (totally sucks for low traffic situations, like at night)

      Green waves for fuel is nothing new, we've been doing so for quite some time already. What's new here is the communication between the vehicles and the intersections (which is pretty much still in heavy research state, and involves a lot more partners then just Audi and BMW)

    15. Re:It astounds me by Eevee · · Score: 4, Funny

      Truth is everybody in Australia is a criminal.

      ...Because iocaine comes from Australia, as everyone knows. And Australia is entirely peopled with criminals. And criminals are used to having people not trust them, as you are not trusted by me...

    16. Re:It astounds me by VolciMaster · · Score: 3, Insightful

      On my way home from work, There is one intersection I always have to wait at all the time for about 3 minutes even though its empty. Rights on reds are prohibited, no sensors, just a timer, and it is a 5 way intersection, So even if right hand turns were allowed on red I would need to do right - U turn, Hard Right (Which is actually completely prohibited at that intersection) U turn, Right. It is very odd because every single other traffic light on the road except for that one has sensors, some even having approach sensors changing the light before the cars even reach them.

      ... You know that if you're biking you can become a pedestrian and cross using the cross walks by pushing your bicycle, and then start biking again, right? :)

      that's what I always do when I can't make turns to get where I need to go.

      --
      antipaucity
  2. Uphill battle by seizurebattlerobot · · Score: 4, Insightful

    Traffic signal timing is nothing new, we've known about it a long time. Unfortunately, there is much money to be made fleecing motorists for traffic violations. As a result, our road systems are tweaked to generate revenue, not expedite traffic. Good luck getting these algorithms used in anywhere but a handful of places without a fight.

  3. Poorly designed vehicle detectors by tepples · · Score: 4, Informative

    With all the red light cameras everywhere (for safety), you'd think they could put a few out there that would make it so I don't spend 3 minutes every morning staring at an empty intersection.

    A lot of traffic signals are on a fixed cycle because the sensors buried in the street often fail to reliably detect a bicycle waiting to turn left (US; mirror in UK/AU/JP), even when the bicycle's wheels are directly over the edge of the loop.

    1. Re:Poorly designed vehicle detectors by jridley · · Score: 4, Insightful

      Roads are for road users. I ride a bike, I obey the laws (ALL of them - way better than ANY car I ever see on the road) and I pay at least as many taxes to pay for the roads as anyone else on the road. If the road isn't designed for my use, it's because the designers screwed up. Bikes were here before cars and they'll be here after cars.

    2. Re:Poorly designed vehicle detectors by tsm_sf · · Score: 4, Insightful

      I'm not going to argue with your point of view (since you're more or less correct), but I would like to point out that offensive (as opposed to defensive) riding is unfortunately essential in a large urban environment. Getting out in front of traffic at a stop light, riding two abreast, moving from sidewalk to road and back again, and splitting lanes are all part of not being hit. For every asshole bunny-hopping the curb or cube-gleaming your fender, there's another who's totally oblivious to the fact that they're behind two tons of metal.

      It's a lose-lose scenario, yet for some reason blame is passed between various forms of commuters instead of placed on urban planners where it so rightfully belongs. We need one lane for transit/commerce/utility, one lane for personal motorized transport, one for muscle powered, and one for pedestrians. Crying that it's difficult is begging the point.

      ((Critical Mass doesn't fit into this picture. It's a protest, and you know full well when and where it will occur. Getting your side mirror bashed or your windshield krypto'd is your own damn fault))

      --
      Literalism isn't a form of humor, it's you being irritating.
    3. Re:Poorly designed vehicle detectors by dr2chase · · Score: 4, Informative

      No no fucking no. They do not work that way. You want to align a large conducting loop or blade across the sensor's AC magnetic flux. It's looking to form a short-circuited transformer with the body of your car, or a bicycle wheel.

    4. Re:Poorly designed vehicle detectors by driptray · · Score: 4, Insightful

      The argument that cyclists don't pay their way is absurd - the reality is the opposite; public funding of roads is a massive subsidy from those who don't drive a car to those who do. As a cyclist I'd love a system of user-pays for roads.

  4. Drawbacks of bikes and buses by tepples · · Score: 3, Insightful

    You want green, invest in buses, trains, bikes, etc.

    Being car-free, I know the limitations of bikes and buses. Bikes can't carry a week of groceries for a family of four at a time, and they're uncomfortable in a thunderstorm or the freezing season. Buses in many cities don't run at night, on Sundays, or on national holidays, due to low ridership.

  5. Interesting perspective... by RyanFenton · · Score: 4, Insightful

    The perspective taken for this bit of problem solving is interesting, because it is stepping above the usual street engineering up to city planning - maximizing the number of people able to use shared resources, while minimizing resources used. This is decidedly NOT a perspective that is common in the US, as our cities tend to 'sprawl' at the whim of investors and politicians with 'complicated' priorities rather than anything as idealized as proper engineering to make best use of resources.

    Greater use of mass transit to maximize available road where possible, waves of greens with appropriate buffers to keep congestion manageable to even extreme capacities, traffic system that work to inform the driver and minimize late decision making - these are good moves.

    I would hope we could use some of these moves to create a road system that would allow for us to approach automated driving systems - where you would decide where you needed to be, and an appropriate vehicle would pick you up within a few minutes, using the minimum amount of fuel for the entire city worth of people using the system, and giving non-automated drivers plenty of road space as they go. Nobody limited in choices - but maximizing efficiency and convenience for everyone.

    It probably won't happen here in the US (different priorities, as mentioned), but I hope such a system could be established in my lifetime.

    Ryan Fenton

  6. Re:So can making only right turns !! by Hijacked+Public · · Score: 3, Informative

    And UPS

    --
    "Sacrifice for the good of The State" - The State
  7. Re:Too Bad It Won't Happen in US by Hijacked+Public · · Score: 4, Funny

    Fucking google street view, passively shooting holes in my arguments.

    But this isn't first time I've been lied to my a marketing person.

    --
    "Sacrifice for the good of The State" - The State
  8. Re:Another reason it's not done in the US... by thePowerOfGrayskull · · Score: 3, Insightful

    The leading cause of death for people between 15 and 35 in the US is automobiles.

    You sound like a big part of the problem.

    The leading cause of death is not automobiles, just like the leading cause of homicides is not guns.

    Every single automobile death is caused by either someone not paying sufficient attention (which includes driving faster than you can plan ahead for any given set of road conditions), or mechanical failure (usually coupled with some degree of someone not paying attention). The idiot who pulled out "right in front of me" today might have caused an accident -- he certainly wasn't paying attention, but I was. I saw the potential for him to make a stupid choice about four seconds ahead of time (as soon as he approached the intersection*) and by the time he actually did it two seconds later, I had already dealt with the situation.**

    The point is this: most accidents require two parties not paying attention: the one who is making the active mistake and does something stupid like pulling into traffic, or driving faster than he can react; and the one who should have seen the possibility for the event to occur, and reacted to avoid it. Obviously this doesn't apply in all cases - but I suspect it does in most. (Heck - even getting t-boned when crossing a protected intersection ... why did you assume you didn't have to look first, just because your light was green?)

    * what is with those people who will pull up to an intersection, sit and STARE at oncoming traffic for several seconds, THEN pull into it, causing much swerving and slamming on of brakes? Are they just spaced out while they watch a few dozen tons of metal bearing down on them, or perhaps they know they *should* look left -- so they do it for form's sake though they've already made up their minds to go?
    ** no, "dealt with" does not mean slamming on the brake and potentially causing more incidents behind me. With so many more controls than the horizontally long pedal in the middle (or left), WHY is that so often a person's first reaction?

    As far as GP goes - I feel his frustration, and it's nothing to do with wanting to speed. Driving in a residential area I only drive as fast as I can comfortably react to the unexpected - often given the potential for kids and animals coming onto the scene from hidden places, it's at or only slightly over the speed limit. But when I hit six lights in a row, and the timing of the lights causes yet more delays and backups because of volume... i can't help but get frustrated at what a waste of time and gas it is. Those lights *could* be sequenced together, but they're simply not -- usually in order to either raise ticket revenue for the city, or because some politician who doesn't know anything about traffic management decides something must be "done" about how unsafe it is in the city.

  9. Re:Greenwashing by mirix · · Score: 4, Insightful

    Cars aren't going away any time soon. So we can:

    A. Do nothing.

    B. Fix the traffic lights for minimal cost and offer some improvement on things.

    But I guess since B doesn't remove cars entirely, we should do nothing right? That's pretty fucked logic you've got there. If doing this saves only 10% on urban fuel consumption, it will have the same effect as 1 out of 10 people stopping driving entirely. Seems like a net positive to me, and a lot more feasible than hoping 10% of people to give up their cars and start walking everywhere.

    My route to work is horrible. I hit nearly every light, every day, even when coming home in the middle of the night. I'd like to send the city a bill for 20%+ of my gas, and half the cost of replacing brakes & clutch when the time comes, as this could have been easily saved by fixing the fucking lights. The rage induced by hitting every light probably knocked a few years off my life too.

    --
    Sent from my PDP-11
  10. Re:Red Wave by eastlight_jim · · Score: 3, Informative

    This policy was changed in 2009 when the Department for Transport realised the error of its ways. It now encourages more of a 'green wave' approach where possible.

    Source

  11. Obligatory XKCD by vidnet · · Score: 3, Funny

    I'd like to smack the idiot who designed this intersection.

    (Also happens to be my favourite xkcd ever, finally I get to use it)