LTE-Based V2I Communication Is the Immediate Cooperative Mobility Opportunity

Audi announced the introduction of its Traffic Light Information System in Düsseldorf, Germany, the second European city to receive the service after Ingolstadt, Germany. The service will initially be available in 150 traffic lights in Düsseldorf, which committed to implementing connectivity in 75% of its traffic lights until the end of September 2020. Audi's Traffic Light System includes two different applications: Green Light Optimized Speed Advice (GLOSA) and Time-to-Green. With GLOSA, the traffic signal controller sends a message to vehicles approaching a signalized intersection via LTE Uu with information about the traffic light schedule. The vehicle uses the received data as input in an algorithm able to calculate a speed advice value, which is displayed in the driver's cockpit. The second application, Time-to-Green, displays the remaining time until the next green light in the driver's cockpit when red lights are unavoidable. The benefits of these applications are improved traffic flow and lower fuel consumption—a pilot study suggests 15% lower fuel consumption. Time-to-Green has been available since 2016, and GLOSA since 2019, in nearly 5,000 intersections in cities and metropolitan areas of the United States. Audi is a pioneer in offering Vehicle-to-Infrastructure (V2I) communication via traditional cellular networks (LTE Uu). The company plans to provide other V2I functionalities in the future, such as interaction with the vehicles' start/stop functions, optimized navigation routing, and other predictive features.

Cooperative mobility refers to a scenario where vehicles, pedestrians, cyclists, and infrastructure components all communicate with each other, making transportation more efficient and safe. Vehicles can bidirectionally communicate to infrastructure components, such as traffic lights, lane markings, and road signs, via traditional cellular networks or direct short-range technologies such as 802.11p and LTE-V2X. While much attention has been given to direct short-range technologies because they allow advanced use cases that can deliver substantial safety improvements—estimations indicate 80% road accident avoidance—these technologies are far from reaching mass deployment. V2I via LTE use cases can be immediately deployed and delivers noticeable traffic efficiency results as well as environmental benefits.

Apart from traffic light information, V2I communication via LTE can deliver many other applications, including electronic toll collection, roadworks warnings, traffic-jam warnings, dynamic lane management, intersection collision warnings, and smart routing. However, only a few Original Equipment Manufacturers (OEMs) offer these services to drivers, mostly because of the low availability of network infrastructure.

Collaboration with cities is paramount for the deployment of these V2I use cases. In the case of signalized intersection applications such as GLOSA, the traffic control center provides the operating program for the traffic lights and real-time data from traffic computers about variables that continually influence traffic light switching, including pedestrian crosswalk buttons, detected loops in the street, and bus or train registrations. OEMs can then use these data to predict how the traffic lights will behave in the next minutes. Additionally, vehicles can anonymously send GPS positions that help identify patterns—for instance, when cars stop at a traffic light for too long—to traffic control centers so they can improve traffic management.

Government authorities must recognize the importance of infrastructure investment to traffic management and develop cooperative mobility projects, such as the NYC Connected Vehicle Project developed by the New York City Department of Transportation (NYCDOT), to foster investments. Collaboration with OEMs is key to guaranteeing their commitment to stimulate the widespread adotion of V2I services. Presently, OEMs offer connected car functionalities in the form of expensive optional packages, preventing high widespread adoption of the technology. For instance, Audi's Traffic Light System is part of the company's monthly Connect Prime subscription, which is available for US$199 for six months or US$499 for 18 months. Meanwhile, OEMs must acknowledge that municipal, city, or transportation authorities are more likely to engage in considerable infrastructure investments if OEMs commit to deploying V2I services at low to no cost in the early years.

Moreover, partnerships with location intelligence companies could compensate for the lack of infrastructure communication, as companies like TomTom and HERE have cameras and radars distributed around cities globally, and their platforms (e.g., HERE’s Open Location Platform) receive information from diverse sources, delivering real-time updates.