AAA Study: Automated Car Systems No Substitute For Driver Engagement


Advanced Driver Assistance Systems (ADAS) offer a significant opportunity to reduce collisions, improve traffic flow and enhance driver convenience. However, a new AAA study reveals that motorists may not fully understand the operation and limitations of these technologies.


AAA’s research found that the 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 by the Automotive Research Center of the Automobile Club of Southern California at Auto Club Speedway.


“While advances in technology and creating safer driver environments hold promise for a future with fewer crashes, multi-tasking drivers could be caught relying too heavily on safety features,” says the Automotive Research Center’s Chief Automotive Engineer Steve Mazor.  “The benefits of these systems can’t help motorists who are not familiar with their use. Safe roads start and continue with drivers who are alert and thinking about driving safely.”


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.


An example of adaptive cruise control function from the test-track program: The Subaru Forester vehicle reacting to a third vehicle cutting in between lead vehicle and test vehicle:  “It locked onto the ‘intruding’ vehicle quickly and smoothly decelerated to open the preset gap,” according to the Auto Club’s Mazor. “Once the lead vehicles resumed their 60 mph cruise, the Subaru slowly sped up to that speed and maintained its lock on the middle vehicle.”


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.