So how are connected and automated vehicles related? Let’s take a look at a traffic signal as an example.
An AV without connectivity is simply using on-board sensors to determine its surroundings. As the AV approaches a traffic signal, much like a human driver, the AV must rely on “seeing” the traffic signal with its sensors and determine from that input whether the signal is red, yellow or green, and how to respond. The AV therefore has no context beyond what a human driver would have. If a large truck is positioned in front of the AV, or if there is heavy rain or snowfall, the AV may be similarly impaired in terms of seeing the traffic signal and determining a response.
However, if the AV were also a connected vehicle, it could receive continuous radio messages from the traffic signal, indicating not only the current signal indication (red/yellow/green), but also the time until the next phase change, providing additional context for determining the speed for approaching the intersection.
In a fully connected system, that information could also help to inform the vehicle of the optimum travel speed to avoid stopping at the next intersection. And while the on-board sensors may not have clear visibility of another vehicle on the nearby cross-street, V2V communication could inform the AV of a vehicle about to violate the red light, allowing it to avoid a potential collision that it might not otherwise be able to detect with sensors alone.
While connected and automated vehicles are two very different things, together these two technologies can make our roadways much safer in the years to come.
Scott Shogan, connected/automated vehicle market leader with WSP USA, has two decades of traffic engineering and intelligent transportation systems experience. His expertise includes traffic operations analysis, microsimulation, and the planning and design of technology applications for improving traffic operations and safety.
[Editor’s Note: To learn more about how WSP supports the planning, deployment and maintenance of intelligent transportation systems and connected and automated vehicle projects across the U.S., visit www.advancingtransport.com.]
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