The University of Tennessee, Knoxville


The Basics of Connected Vehicles

Source: Airton Kohls and USDOT Intelligent Transportation Systems Joint Program Office

I believe it is fair to say that Connected Vehicle Technology is going to be a part of our Tennessee transportation system in the very near future. So, do you know what Connected Vehicles are? How do they work? How will they be used and what are their benefits?


The U.S. Department of Transportation's (USDOT's) Connected Vehicle program is working with state and local transportation agencies, vehicle and device makers, and the public to test and evaluate technology that will enable cars, buses, trucks, trains, roads and other infrastructure, and our smartphones and other devices to "talk" to one another. Cars on the highway, for example, would use short-range radio signals to communicate with each other so every vehicle on the road would be aware of where other nearby vehicles are. Drivers would receive notifications and alerts of dangerous situations, such as someone about to run a red light as they're nearing an intersection or an oncoming car, out of sight beyond a curve, swerving into their lane to avoid an object on the road.

Connected vehicles could dramatically reduce the number of fatalities and serious injuries caused by accidents on our roads and highways. While the number of people surviving crashes has increased significantly thanks to airbags, anti-lock brakes, and other technology, the USDOT is shifting its focus from helping people survive crashes to preventing crashes from happening in the first place.

Every year, there are over 5 million crashes on our roads. Of these crashes, over 30,000 people still die, and many more sustain serious injuries, according to the National Highway Traffic Safety Administration (NHTSA). In fact, the leading cause of death among young children and young adults is vehicle crashes, according to the Centers for Disease Control. Another NHTSA study of connected vehicle technologies has shown that they have the potential to reduce up to 80 percent of crashes where drivers are not impaired, which would save a significant number of lives and prevent millions of crash-related injuries every year.

A safety application such as Forward Collision Warning (FCW) alerts the driver to an imminent collision in order to help avoid or mitigate the severity of crashes into the rear end of other vehicles on the road.

Connected vehicles have significant advantages over new technologies now appearing in high-end vehicles, such as radar, cameras, and other sensors. For one thing, connected vehicle technologies and applications have a greater range than on-board vehicle equipment, which will allow you to receive alerts of hazardous situations much earlier, providing more time to react and prevent an accident. Also, connected vehicle technology doesn't depend on "line of sight" communications to be effective, unlike radar. So if a car ahead of you is braking hard on the other side of a hill due to an obstruction, you would receive notification even though you can't see and aren't aware of the dangerous situation developing. Connected vehicle technology is also less expensive to install than radar and camera equipment in vehicles. This will enable it to become standard equipment in the future on practically all vehicles, not just luxury cars.

Connected Vehicle technologies aim to tackle some of the biggest challenges in the surface transportation industry--in the areas of safety, mobility, and environment. Safety applications center on the basic safety message (BSM), a packet of data that contains information about vehicle position, heading, speed, and other information relating to a vehicle's state and predicted path. The BSM contains no personally identifying information. Connected Vehicle safety applications will enable drivers to have 360-degree awareness of hazards and situations they cannot even see. Through in-car warnings, drivers will be alerted to imminent crash situations, such as merging trucks, cars in the driver's blind side, or when a vehicle ahead brakes suddenly. By communicating with roadside infrastructure, drivers will be alerted when they are entering a school zone, if workers are on the roadside, and if an upcoming traffic light is about to change.

Another example, "queue warning" is an application that will let you know way ahead of time of a backup forming in your lane. You would receive enough notice to slow down, change lanes, or even take a different route. There are also mobility applications that will enable your car to communicate wirelessly with parking meters in the area to find open parking spaces, or use your smartphone to arrange a last-minute rideshare partner. Another application could even enable a disabled pedestrian to use a wireless device to communicate with a traffic signal to safely cross a busy intersection. Also, traffic managers will be able to control the flow of traffic more easily with the advanced communications data available and prevent or lessen developing congestion. This could have a significant impact on the environment by helping to cut fuel consumption and reduce emissions. These are just a few of the many mobility applications in development that have the potential to make your travel smoother, timely, and even relaxing.

To learn more about Connected Vehicles, please go to : For a list of Connected Vehicle applications, visit


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