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In July, at the Association for Computing Machinery MobiSys conference, research teams from the Massachusetts Institute of Technology (MIT) and Princeton University took home an award for a fuel-saving system in cars that relies on dash-mounted smartphones.
MIT says the system saves fuel by monitoring and logging the timing of traffic signals to alert drivers when slowing down could help them avoid idling at lights. By reducing idle times, MIT says the system can save gallons of gas. In tests conducted here in the States, drivers saw a massive 20-percent reduction in fuel consumption.

Dubbed SignalGuru, the idle-reducing system relies on countless images captured by the phones' cameras. SignalGuru is able to analyze these images to predict when traffic lights will change. Somehow, the fuel-saving system works on both fixed-schedule lights and on signals that vary in duration based on traffic flow. The only downside to Signal Guru seems to be that its light-predicting accuracy varies depending on the number of vehicles outfitted with the system, which makes sense.

Oh, and, as all good scientists should, the researchers did model the impact of instructing drivers to accelerate to beat the red lights, just to see what would happen. They concluded that running the red light could be disastrous for economy figures, so the system now recommends slowing down. Science wins again! Check out more details of the study in the official press release after the jump.
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MIT: Increasing fuel efficiency with a smartphone

--A network of dashboard-mounted phones can collect data on traffic lights and tell drivers how to avoid inefficient stopping and starting.

CAMBRIDGE, Mass. -- In July, at the Association for Computing Machinery's MobiSys conference, researchers from MIT and Princeton University took the best-paper award for a system that uses a network of smartphones mounted on car dashboards to collect information about traffic signals and tell drivers when slowing down could help them avoid waiting at lights. By reducing the need to idle and accelerate from a standstill, the system saves gas: In tests conducted in Cambridge, Mass., it helped drivers cut fuel consumption by 20 percent.

Cars are responsible for 28 percent of the energy consumption and 32 percent of the carbon dioxide emissions in the United States, says Emmanouil Koukoumidis, a visiting researcher at MIT who led the project. "If you can save even a small percentage of that, then you can have a large effect on the energy that the U.S. consumes," Koukoumidis says.

The system is intended to capitalize on a growing trend, in which drivers install brackets on their dashboards so that they can use their smartphone as a GPS navigator while driving. But unlike previous in-car cellphone applications, the new system, dubbed SignalGuru, relies on images captured by the phones' cameras. According to Koukoumidis, the computing infrastructure that underlies the system could be adapted to a wide range of applications: The camera could, for instance, capture information about prices at different gas stations, about the locations and rates of progress of city buses, or about the availability of parking spaces in urban areas, all of which could be useful to commuters.

Fixed or flexible?

Koukoumidis is a student of Li-Shiuan Peh, an associate professor in the Department of Electrical Engineering and Computer Science who came to MIT from Princeton in fall 2009. Koukoumidis came with her, and together they launched the SignalGuru project as part of the Singapore-MIT Alliance for Research and Technology's Future Urban Mobility program. Koukoumidis's other thesis advisor, Princeton's Margaret Martonosi, is the third author on the MobiSys paper.

In addition to testing SignalGuru in Cambridge, where traffic lights are on fixed schedules, the researchers also tested it in Singapore, where the duration of lights varies continuously according to fluctuations in traffic flow. In Cambridge, the system was able to predict when lights would change with an error of only two-thirds of a second. In suburban Singapore, the error increased to slightly more than a second, and at one particular light in densely populated central Singapore, it went up to more than two seconds. "The good news for the U.S.," Koukoumidis says, "is that most signals in the U.S. are dummy signals" - signals with fixed schedules. But even an accuracy of two and half seconds, Koukoumidis says, "could very well help you avoid stopping at an intersection." Moreover, he points out, the predictions for variable signals would improve as more cars were outfitted with the system, collecting more data.

Theory into practice

The researchers did model the effect of instructing drivers to accelerate in order to catch lights before they changed, but "we think that this application is not a safe thing to have," Koukoumidis says. The version of the application that the researchers used in their tests graphically displays the optimal speed for avoiding a full stop at the next light, but a commercial version, Koukoumidis says, would probably use audio prompts instead.

Koukoumidis envisions that the system could also be used in conjunction with existing routing software. Rather than recommending, for instance, that a car slow to a crawl to avoid a red light, it might suggest ducking down a side street.


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  • 22 Comments
      Mr Smooth
      • 3 Years Ago
      Why can't local municipalities just time the lights on major thoroughfares during peak usage hours? There is a 2 mile stretch of 4 lane road near my house where I routinely get stopped for at least 3 demand lights when I drive down it. Now add in the thousands of other cars per day that do the same thing and think of how much gas is wasted. Simple traffic studies and timing the lights could save massive amounts of fuel, but our government would rather waste money by subsidizing and pushing hybrid and electric vehicles down our throats.
        BG
        • 3 Years Ago
        @Mr Smooth
        In many cities, lights are timed, and I have been to some where signs state what the speed should be to pass through the intersections. But the plan does not work with the typical modern semi-trained driver. The sign may say 25 mph, but they drive 40 and have to mash on the brake at every light. It's as if this level of complexity doesn't click with them.
        tegdesign
        • 3 Years Ago
        @Mr Smooth
        Very similar to my initial thoughts. I've often thought that whom ever is in charge of light timing might have an agenda contrary to free flowing traffic. In many place poorly timed lights seem intentionally set up to impede the flow of traffic especially through urban areas. I don't think it has to do with keeping speed down since a speeder would just get to a red light faster and have to wait. Am I the only one who thinks this or am I a little bit of a conspiracy theorist. I just feel that those in planning departments have a bit of a God complex (why else would you get into that line of work?) and also seem consistently anti automobile.
      BG
      • 3 Years Ago
      What? Absurd. Most modern drivers are impatient, reactive drivers, meaning they accelerate furiously, then mash on their brakes at the last possible moment. I have seen hundreds, thousands of drivers on a straight, flat road with perfect visibility where a red light way up ahead was clearly visible drive furiously up to the light and then have to jam on their brakes. Letting up on the gas and coasting up to the intersection was totally beyond them. The idea of this technology is great, but it will take a lot of driver training to get Americans to re-learn how to drive.
      Quattro
      • 3 Years Ago
      Fanboy reporting lol. Audi has this tech in trials called Travolution: http://www.youtube.com/watch?v=dfShI1YqYWo
      NissanGTR
      • 3 Years Ago
      What vehicles were used? I'm guessing SUV and trucks as just a few mpg will really improve economy percentage wise.
      Skicat
      • 3 Years Ago
      Properly sync'ed traffic lights and idiots not speeding between them can accomplish this without the phone. Unfortunately, most morons on U.S. roads hardly know anything about driving, much less anything about synchronized lights and driving the speed limit. They'll only way they MIGHT get it when there's an app for it.
      The Calligrapher
      • 3 Years Ago
      Yeah... That's what we need: more people just "rolling" to the red light for going straight, while the people intending to make a left or right turn are stuck behind them. "Why are you flashing your headlights? The light is red, Bla bla bla..." There is enough idiots of that kind on the roads already.
      Audrey Roundtree
      • 3 Years Ago
      After reading some of the comments I am amazed at the number of people who find it more practical to rely on a dysfunctional government that bleeds money to replace all existing traffic lights than for the growing number of drivers with smart phones to merely download and use an app with audible commands. My favorite though, is demolishing our current intersections to make traffic circles. That would be an efficient use of our resources. I can't wait for Ford Motor Company to make this technology available on future Lincolns.
      DarwinianReject
      • 3 Years Ago
      Cool! Let's integrate this system into the electronics of cars. I slow down when approaching red lights in hopes of it turning green just as I get there (look for the yellow going the other direction). It makes for a more mellow ride and of course saves time and gas. Having a countdown to green will definitely help!
      yupt
      • 3 Years Ago
      thing like these that i'm losing faith on MIT. Wasn't these proven already by stop-start system.
      stclair5211
      • 3 Years Ago
      How about we drill a few holes and find some more oil. If big brother wants to use this tech and hybrids and whatever else on their buses to save fuel fine, but last time I checked I pay for my gas and i'd like to just be able to drive a simple pleasant car. Not one with a smartphone glued to the dash with regenerative brakes and batteries and whatever else. KISS. Save 20% in fuel and waste 20% in the long run maintaining these systems in time and fixed costs. It's a wash people. If Verizon sponsored this i wouldnt be surprised because not everyone has a smartphone or a $29 data plan. Now they do!
      DashRipRock
      • 3 Years Ago
      I'm calling a bit of BS on that straightforward 20 percent savings. What percentage of vehicles actually operate in the city and will have any opportunity for such potential savings? The new Start/Stop systems in vehicles have not advertised even remotely such savings possible, how can this save even more? Furthermore, this assumes the surrounding traffic is cooperating fully with the speed of travel which is highly unlikely. I think a more practical approach is smart lights and in some cases, simple round-abouts where traffic is not expected to stop at all. Unfortunately, in the US, the round-abouts I have seen were very poorly designed. Also, how about an app that communicates with the light for motorcycles. So often, the lights do not detect a motorcycle and will not change at all. We are left to fend for ourselves against traffic. Time to fix that for sure.
        vette982
        • 3 Years Ago
        @DashRipRock
        The idea behind this project is that traffic signal detection/prediction can be achieved without any connection to a city's traffic management infrastructure. While it's a valid problem, an app that allows motorcycles to notify traffic lights when they arrive at an intersection would require a connection to the city infrastructure, which would be quite difficult given the resistance encountered when working with the government transportation authorities, not to mention the investment required by the government to put such infrastructures in place.
      Bren Hering
      • 3 Years Ago
      Hi, I'm Bren Underwood with the agency that represents FRAM Group the maker of FRAM, Prestone and Autolite. With there being an app for just about everything these days, why not have one for fuel efficiency? Per this post, research teams at MIT and Princeton recently released study results for a smartphone program/application that helps drivers to reduce idle time to increase efficiency. The experts at FRAM Group also recommend taking your car in for a maintenance checks such as checking/changing spark plugs, filling tires, and replacing air filters can improve gas mileage by up to 4 percent and also keep your car running in great. For more info, check out FRAM.com, Autolite.com and Prestone.com. Keep driving smart!
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