Cars talking to traffic lights could be a thing in the near future.

If you like the thought of your car communicating with other cars on the road, you’ll love having it “talk” with traffic lights and other bits of infrastructure. That’s the I part of V2I technology that Cadillac recently tested, where a specially equipped CTS sedan received an alert from a traffic signal as the car approached. The message advised the driver of a “potential red light violation at current speed.” You know, the same thing your mother-in-law says when she’s in the car with you, only without the screaming and condescending attitude.


Check out:


The technology works just like Cadillac’s vehicle-to-vehicle system, using Dedicated Short-Range Communication (DSRC) as well as GPS to monitor the car’s location and communicate with any fixed objects in the area that are similarly equipped. The traffic light used in this test was outside GM’s Warren Technical Center near Detroit, and was developed in conjunction with the Michigan Department of Transportation, the Macomb County Department of Roads, and GM Research and Development.

Obviously, this turn of events could be a bit unnerving for some. If a traffic light can communicate its status with the car, and the car uses GPS to know its exact speed and position on the road, it would seem Big Brother can easily find out who runs a red light. Presumably, the same thing could take place with high-traffic areas monitoring congestion, or twisty sections of road that advise people to slow down. To quell those fears, Cadillac is adamant about the anonymity of the system; no identifying information about the car, vehicle registration, or MAC address for the on-board computer is ever sent. Furthermore, extensive firewalls and “other measures” are in place to prevent hackers from gaining access to the information.

At least, that’s how it works in theory.

Cadillac offers no timeframe as to when V2I might become reality. That would of course depend on smart infrastructure development, and that’s out of the manufacturers hands. V2V systems, however, are currently offered as standard equipment on all CTS models.

Source: Cadillac

Gallery: Cadillac V2I Technology

Hide press releaseShow press release

Cadillac Builds on V2V Deployment with V2I Development


  • Successful demonstration of Vehicle-to-infrastructure communication on public roads
  • Cadillac CTS development vehicles received data from traffic signals
  • in collaboration with Michigan road agencies

NEW YORK – Cadillac’s CTS sedan, one of the first production vehicles in the world to contain Vehicle-to-Vehicle (V2V) communication, has now successfully demonstrated Vehicle-to-Infrastructure (V2I) capability in Michigan. Cadillac CTS development vehicles received real-time data from traffic controllers on signal phasing and timing during successful demonstrations recently conducted in collaboration with Michigan road agencies.

V2I connects the Cadillac development vehicles to its surrounding infrastructure, allowing the vehicle to alert the driver of safety, mobility or environment-related conditions ahead.

The traffic signals, located adjacent to the GM Warren Technical Center campus at the intersections of 12 Mile and 13 Mile roads, were able to send real-time data using Dedicated Short-Range Communications (DSRC) protocol to the development vehicles, which alerted the drivers of a potential red light violation at current speed. This alert helps avoid the dangerous decision to either brake abruptly or accelerate through a busy intersection.

To ensure the privacy of the driver, the vehicles do not transmit any identifying information such as VIN number, registration or MAC address, in their messages. For example, if a connected car runs a red light, the traffic signal may be able to say someone ran a red light, but will not be able to say who or what vehicle. As for cybersecurity, firewalls and other measures are used to ensure the DSRC signals cannot be interfered with and are only exchanged between the vehicle and the infrastructure. This is similar to the encryption used on Cadillac’s V2V technology.

The Michigan Department of Transportation, Macomb Country Department of Roads, and General Motors’ Research & Development are collaborating to showcase leadership in the connected and automated vehicle environment. Development of safety technologies, such as V2V and V2I communications, lays the groundwork for a connected, safer future.

Cadillac's V2V solution uses GPS for positioning and DSRC for communication, which can handle 1,000 messages per second from vehicles up to about 1,000 feet away. V2V-equipped vehicles create an ad hoc wireless network that allows for the transfer of information without relying on sight lines, good weather conditions or cellular coverage.

V2V is included as a standard feature on the 2017 CTS sedan in the U.S. and Canada and complements a robust suite of available active safety features.