Talking Traffic Lights

Audi’s car communication feature aims to minimize stops

At the end of February 2019, Audi became the first car-maker in the US to roll out a Green Light Optimized Speed Advisory (GLOSA) service, called Traffic Light Information, that informs drivers how fast or slow to drive when approaching a green traffic light.

The system pulls timing data from nearby traffic lights using a car’s LTE connection and displays that on its dashboard and on a heads-up display projected on the windshield. To suggest driving speeds, it does some quick maths based on data of the distance between the car and the traffic light, the local speed limit and the timing of upcoming traffic signals. All of this is then neatly packaged into a recommended speed and shown on the dashboard.

The aim is to save drivers time and to reduce environmental damage from idling. Data from the AAA Foundation for Traffic Safety shows that an average US driver spends nearly 300 hours a year behind the wheel, and much of this is at a standstill. Giving motorists additional information through a GLOSA service can help lower driving anxiety and improve people’s comfort during their time behind the wheel.

Traffic Light Information is available to drivers who subscribe to Audi’s Connect Prime feature on select 2017 and 2018 models. It lets cars communicate with infrastructure in certain cities and metropolitan areas in the US. The system also tells drivers the state of a traffic light even before they approach it, so that they can adjust their driving speed accordingly. Audi first released the technology in 2016 in Las Vegas, and has now brought it to 4,700 intersections in cities including Dallas, Denver, Gainesville, Houston, Kansas City, Las Vegas, Los Angeles, New York City, Orlando, Phoenix, Portland, San Francisco, Washington, DC and northern Virginia.

As more vehicles embed such systems in the coming years, it’s expected that the technology will help make the broader driving landscape safer. Vehicle-to-infrastructure communication technologies like GLOSA greatly benefit drivers and are another step in the evolution of autonomous driving and cars of the future. This kind of application is what we believe connectivity and technologies such as cellular vehicle-to-everything communication, or C-V2X, will enable (see Connectivity Is Forming the Basis for Car Innovation). Audi’s announcement is a start; C-V2X will enable that to scale and without dependence on cellular coverage.