WHAT’S THE DIFFERENCE BETWEEN AUTOMATED AND CONNECTED VEHICLES?

Even though the terms automated vehicles and connected vehicles are often used in tandem, they are actually vastly different technologies. Some vehicles will be connected but not automated, others will be automated but not connected, and some will have both capabilities.

Connected vehicles wirelessly communicate with each other, connected infrastructure (like traffic signals) and other travelers. The data sent from connected vehicles is anonymous. This data can help drivers avoid crashes and enable transportation agencies to improve mobility and reduce congestion. Connected vehicle systems can involve vehicle-to-vehicle (V2V) or vehicle-to-infrastructure (V2I) communication. Vehicles may also communicate to other travelers, like pedestrians or bicyclists, sometimes referred to as vehicle-to-pedestrian (V2P) communication. The combined capability of these modes is often referred to as vehicle-to-everything (V2X).

Automated, “driverless” or “self-driving” vehicles utilize sensors, cameras, GPS, artificial intelligence, and other hardware and software to control, navigate and drive the vehicle without direct human input. Vehicles that are fully automated are not available yet.

Automated vehicles are vehicles that have some automated features but are not completely automated. Using the same on-board sensor technology as in automated vehicles, these vehicles can take over some, but not all, of the driving function of the human driver. The driver still needs to be available to monitor or take over other driving functions. Many newer automobiles have automated features.

HOW DOES CAV TECHNOLOGY WORK?

CAV technology can work in a variety of ways based on its function. Connected vehicles use special short-range radios to wirelessly communicate with each other, connected traffic signals, or other infrastructure features. Automated vehicles utilize artificial intelligence, sensors, cameras, GPS and other hardware and software to operate, partially or fully, without direct human input to control the steering, acceleration and braking. A connected and automated vehicle can use a combination of these technologies. CAV technology is a buzz word lately, but some CAV technologies have been deployed on our vehicles for several years already. Adaptive cruise control, blind spot monitoring, braking assistance and back up assistance, using automated vehicle technology, are all early forms of a CAV.

HOW SOON WILL CAV TECHNOLOGIES BE ON OUR ROADS?

Many new vehicles today have some automated features, such as adaptive cruise control, automated parking or lane changing. Automakers are continually improving and expanding those features. It will likely be years before vehicles will be available that are fully automated, or driverless.

Connected vehicle technologies have been deployed on a limited number of General Motors vehicles in the U.S. over the past few years. Other automakers have indicated intentions to add these capabilities by 2022 or 2023. UDOT and other agencies have deployed connected vehicle capabilities on some fleet vehicles, and will expand those deployments.

WHAT ARE THE SIX LEVELS OF DRIVING AUTOMATION?

WHERE DO I LEARN MORE ABOUT CONNECTED AND AUTOMATED VEHICLES (CAVS)?

List of resources:

• Connected Vehicles
• U.S. Department of Transportation Automated Vehicles Program
• National Highway Traffic Safety Administration
• U.S. Department of Transportation Connected Vehicles Pilot Program
• Cooperative Automated Transportation (CAT) Coalition

HOW DO I KNOW THAT CAVS ARE SAFE?

All vehicles are required to be compliant with Federal Motor Vehicle Safety Standards. The National Highway Traffic Safety Administration (NHTSA) monitors the transportation system and recalls vehicles that are not operating safely. The safety of automated vehicle systems is a topic of active discussion. NHTSA has issued a policy document outlining 12 key safety design elements and is working on safety standards that will apply specifically to vehicles that are highly automated. The companies that build automated vehicles test their vehicles aggressively and certify that they comply with NHTSA safety elements. NHTSA states that although companies are testing complex and advanced automated vehicles, they will not be released to the public until their safe operation is ensured.

WHAT IS A TRANSIT SIGNAL PRIORITY (TSP) SYSTEM AND HOW DOES IT WORK?

A TSP system uses V2I communication between transit vehicles like buses and traffic signals. When buses are behind schedule, the TSP system can automatically request additional green time from a connected traffic signal so the bus can have priority to move through the light and get back on schedule. UDOT has deployed a Transit Signal Priority system on several routes in Salt Lake and Utah Counties.

WHAT IS SNOWPLOW PREEMPTION AND HOW DOES IT WORK?

A preemption system uses V2I communication to allow critical vehicles, like emergency responders, to request a green light at a connected traffic signal so the vehicle can continue toward its destination without stopping. UDOT utilizes a connected vehicle preemption system on some roadways to keep snowplows moving through traffic signals while they are actively plowing. Snowplow preemption will enhance safety by allowing for quick and efficient removal of snow from our roadways.

WHAT ARE CONNECTED VEHICLE SPOT WEATHER IMPACT WARNINGS?

Connected vehicle spot weather impact warnings use V2I communication to send location-specific weather warnings directly to drivers as they approach adverse road conditions like ice or fog. Sensors installed along the road, and information gleaned from previous vehicles, provide the information needed to determine the nature of the warning message. Providing specific warnings at roadway segments with high rates of weather-related crashes will reduce these crash rates.

HOW DO CONNECTED VEHICLES PROTECT MY PRIVACY?

V2X systems are being designed to follow nationally-adopted standards. According to these standards, messages that are sent by the vehicle do not include any information that identifies the specific vehicle, its make, model, VIN or registration number, or identity of the owner or driver. Only the vehicle length is transmitted. In addition, these messages will be encrypted with a security credential, similar to the credentials that protect our credit card information when we shop on-line.

Cars that employ automated vehicle features sometimes have cellular-based telematics systems that communicate vehicle performance information to the company that built the vehicle. This is used to detect problems with the system and to update software over-the-air. Owners of these vehicles agree to sharing this information as part of their license agreement. This communication is separate and distinct from connected vehicle technologies for safety and mobility improvements.

WHAT COMMUNICATION TECHNOLOGIES ARE USED FOR CONNECTED VEHICLE SYSTEMS?

In order for connected vehicle data to prevent crashes, it must be transmitted very quickly – in fractions of seconds. To accomplish this, radio technologies have been developed specifically to communicate crucial data between vehicles and the infrastructure with ‘low latency”. The first technology, Dedicated Short-Range Communication (DSRC) is a wireless radio technology, much like wifi, that facilitates very fast communication of critical data over a range of about 1000 feet. The second technology, Cellular Vehicle to Everything (C-V2X) is very similar but operates on principles similar to our 4G cell phones. Both of these systems use the FCC-designated 5.9GHz spectrum and communicate directly, not through a tower. Most of the early connected vehicle systems, including the UDOT deployments, used DSRC. UDOT also has deployments using C-V2X technology.

In 2021, the Federal Communications Commission (FCC), over the objections of transportation agencies around the country, reduced the width of the 5.9GHz spectrum available for connected vehicle and ruled that DSRC would be replaced by C-V2X. Further insights into this FCC ruling and UDOT’s response to the FCC can be found in the “Resources” section of the “What We’re Learning” section of this website. Final rules about the use of C-V2X are still pending, but some agencies, including UDOT, are beginning to replace early DSRC deployments with C-V2X technology, and most new deployments are using C-V2X.

Data shared in connected vehicle systems  are often transmitted to traffic management agencies. This is usually done over fiber optic cables from the traffic signal or other infrastructure devices that have connected vehicle capability. This data may be used in real time to identify crashes, determine road conditions, respond to congestion or provide useful information to motorists. It may also be stored in local or cloud-based data systems for broader analysis of conditions. All of this data is anonymous and is usually aggregated for analysis.

HOW WILL OUR TRANSPORTATION WORK WHEN THERE ARE SOME CAV VEHICLES MIXED WITH NON-CAV VEHICLES?

Our roadways always have mixed forms of traffic: cars, buses, trucks, old and new vehicles, vehicles driven by experienced drivers and vehicles driven by newer drivers. Vehicles with CAV capabilities will increase gradually over several decades and will mix with vehicles with many different capabilities. CAVs are being designed to operate in the same way traditional vehicles do, generally following the same traffic laws. In fact, highly automated CAVs may be more compliant with traffic laws than human-driven vehicles. CAVs will have the enhanced capability to detect activities all around them and respond appropriately. When a human-driven, traditional vehicle speeds up, slows down, or turns, the CAV will respond to those actions. Similarly, human drivers will respond to actions by CAVs.

One unique feature of a vehicle without a human driver is that another traveler (driver, pedestrian, bicyclist, etc) will not be able to make eye contact with the automated vehicle. Eye contact is a function we use to ensure our safety by acknowledging that we have been seen. Automated vehicle developers are working on systems to replace this kind of interaction, such as light indicators.

CAV developers are exploring ways to provide needed information to first-responders. These vehicles need to respond to sirens and flashing lights, provide vehicle registration data to officers, and otherwise comply with traffic laws. These features are being actively developed.