Audi is revving up its slick Traffic Light Information (TLI) system. Now Audi TLI can tell you the best speed to drive in order to hit a string of green traffic lights, without having to suddenly speed up to make a light on yellow, or brake hard if you can’t speed up enough.
For TLI to work, it requires a grid of traffic signals that report their status — green, yellow, red, and how many seconds ’til the next signal change — to cars with onboard telematics modems and the ability to read the signal information. TLI initially gave you enough information to know if you should slow down for the next light, and a countdown timer until the light turns green again.
Audi calls the feature GLOSA, or Green Light Optimized Speed Advisory. GLOSA is the next step in Audi’s industry-first use of smart traffic lights and onboard telematics to reduce some of the minor hassles of daily driving. According to Audi, the distance to stop, the speed limit profile for the area, and the signal timing plans are all used to calculate the speed recommendation displayed to the driver. If he or she follows the advice and drives the recommended speed, the chances increase that the driver will hit multiple green lights before having to stop. Already, some traffic lights are sequenced to give you multiple greens if you travel at or just below the speed limit, but what works going north on a roadway doesn’t work going south. Audi GLOSA brings more opportunity to catch multiple greens.
Next traffic light is green. Audi GLOSA indicates the best speed to hit multiple lights on green is 25 mph here. (Although if 25 mph works, wouldn’t multiples of 25 do the trick, too?)
Audi’s initial work, in collaboration with the company Traffic Technology Services (TTS), kicked off in 2016 as Audi Traffic Light Information with a demo in Las Vegas, which has the nation’s highest fraction of centrally controlled traffic lights. In 2018, Audi TLI expanded to more cities including Washington, DC. Now, more than 4,700 intersections across the US support both time-to-green and GLOSA functions.
Currently, time-to-green and GLOSA information are available in Dallas, Denver, Gainesville, Fla.; Houston, Kansas City, Kansas; Las Vegas, Los Angeles, New York City, Orlando, Fla.; Phoenix, Portland, Ore.; San Francisco, and Washington, D.C. and northern Virginia. Not every light is covered in the region.
This is one example of what you can do with traffic management systems and V2I, or vehicle to infrastructure, technology. Because these are public traffic signals, the information is available to all automakers. Audi is the one out front.
The light ahead, or the light you’re stopped at, is red. Audi’s original TLI system shows a countdown timer until green.
On an Audi, you need a 2016 or newer Audi (some not all models) with 4G telematics and the Audi Connect Prime level of telematics service. If the driver approaches a red light, the instrument panel or head-up display gives a countdown in seconds until the light turns green. (It stops counting at 3 seconds then goes blank, to avoid wannabe drag-racers from timing green to the millisecond and getting T-boned by the driver at right angles still clearing the intersection a second after his or her light went red.) When the light is green, the instrument panel shows the recommended speed for maximizing the number of greens.
Audi envisions expanded V2I technology to include controlling the stop/start system, optimized routing, and predictive services generally.
Mark Del Rosso, Audi of America’s president, says:
Audi is committed to moving America in many ways, including through the development of industry-leading connectivity and mobility solutions. Not only do vehicle-to-infrastructure technologies like GLOSA benefit drivers today, they’re also the critical steps needed as we continue toward an automated future.