Automated Vehicle Systems Not a Substitute for Driver Engagement

Advanced driver assistance systems (ADAS) offer a significant opportunity to reduce collisions, improve traffic flow and enhance driver convenience. However, motorists may not fully understand the operation and limitations of these technologies. AAA’s research found that the assumptive gap poses a risk for distracted drivers. Although the adaptive cruise control and autonomous braking systems performed as described in the owner’s manuals, motorists unfamiliar with these devices may not be prepared for instances when the technology does not engage. The AAA research was conducted with the Automotive Research Center of the Auto Club of Southern California.

“There are significant benefits to this technology, but these systems have limitations, and multi-tasking drivers could be caught off guard by relying too heavily on safety features,” says John Nielsen, managing director, AAA Automotive Engineering and Repair. “The benefits of these systems could easily be outweighed if motorists are not familiar with their operation or lessen focus behind the wheel. Technology is not a substitute for an alert, engaged driver.”

The National Highway Traffic Safety Administration’s New Car Assessment Program highlights crash-avoidance technologies “to help consumers buy a safer car.” These systems can alert a driver to a potential crash, adjust the vehicle’s pace to maintain a pre-set speed, and even brake independently to avoid a collision. Automakers are ramping up ADAS deployment to maximize safety benefits, increasing motorist exposure to autonomous systems.

To better understand how adaptive cruise control and autonomous braking function, AAA conducted test-track simulations consisting of a variety of typical commuting scenarios. Overall, the simulations demonstrated that adaptive cruise control did a good job of maintaining a specified following distance when traveling behind slower-moving vehicles in a highway setting. However, autonomous braking systems did not always recognize obstacles, provide a warning signal or engage the brakes to slow or stop the vehicle. AAA’s research team also observed that:

• Adaptive cruise control systems performed best when following more closely than AAA’s recommended three-second rule.
• Tracking a vehicle at highway speeds while navigating a mild curve was unexpectedly difficult, but improved when following distance was reduced.
• The ability to recognize obstacles varied between vehicles. The owner’s manuals for these vehicles warn that the systems may not recognize or react to motorcycles, a stopped vehicle, traffic cones or other obstructions.

Automakers have noted system limitations in owner’s manuals; but there are many indications that motorists often do not fully read the manual. Television commercials highlight capabilities without any indication of system limitations, and that input is the primary source of motorist knowledge about what these systems can do. AAA suggests safety gaps could be reduced if:

• Automakers enhance communication to make clear and obvious the limitations of these systems.
• Motorists become thoroughly familiar with all the technology in their car including advanced driver assistance systems before operating the vehicle.

Additional information regarding AAA’s tests of adaptive cruise control and autonomous braking is available on the AAA NewsRoom.

As North America’s largest motoring and leisure travel organization, AAA provides more than 54 million members with travel, insurance, financial and automotive-related services. AAA’s Automotive Engineering team conducts proprietary research to better understand consumer implications of automotive technology, design and functionality. Since its founding in 1902, the not-for-profit, fully tax-paying AAA has been a leader and advocate for the safety and security of all travelers. AAA clubs can be visited on the Internet at AAA.com.