Active driving assistance systems are widely available and often called semi-autonomous because they combine vehicle acceleration with braking and steering. Since its introduction, there have been numerous newsworthy instances of drivers misusing the systems by watching videos, working, sleeping, or even climbing into the backseat. This behavior can go undetected by the vehicle and, in some cases, result in deadly crashes.

To prevent such activities, vehicles with this technology monitor drivers using either a camera-based system, which watches their face, or a system that monitors steering wheel movements. AAA test drove four popular makes and models in real-world conditions on a California highway to evaluate these systems’ effectiveness.

Key research findings include the following:

• Camera-based systems alerted disengaged drivers 50 seconds sooner and were more persistent than those detecting steering wheel movement when the driver was looking down with head facing forward, hands off the wheel.
• Camera-based systems alerted disengaged drivers 51 seconds sooner compared to steering wheel movement when the driver was facing away from the road, looking at the center console, with hands off the wheel.
• On average, the percent of time test drivers were engaged was approximately five times greater for camera-based systems than for steering wheel systems.
• Steering wheel monitoring required only minimal input to prevent system alerts, allowing up to 5.65 continuous minutes of distraction (at 65 mph, equivalent to over 6 miles of disengaged driving). In comparison, camera-based systems allowed 2.25 minutes of distraction during the ten-minute long test drive.

Even after issuing multiple warnings of inattentive driving, both systems failed to disable the semi-autonomous features and force the driver to take the wheel and pay attention.
“Regardless of brand names or marketing claims, vehicles available for purchase today are not capable of driving themselves,” said Brannon. “Driver monitoring systems are a good first step to preventing deadly crashes, but they are not foolproof.”

AAA recommends that automakers opt for camera-based driver monitoring systems over steering wheel monitoring; however, more refinement is required to prevent driver distraction and misuse. Before releasing this report, AAA met with automakers to provide insight from the testing experience and specific recommendations for improvement.

Vehicles equipped with camera-based driver monitoring systems were significantly better at preventing each type of tested distraction scenario by issuing alerts faster and more persistently than a steering wheel system, no matter the external lighting conditions. On average, the percent of time test drivers were forced to focus on driving was five times greater when facing a camera than with steering wheel input.

Both driver monitoring types were prone to being intentionally fooled, although those using a camera were harder to trick. AAA test drivers attempted to stymie monitoring system alerts with periodic head or eye movement and manipulating the steering wheel. Each driver was given the discretion to develop their cheat strategy, and it should be noted that no external devices, tools, or aids were used.

AAA continues to urge automakers to adopt an industry standard naming convention , for vehicle technology to prevent drivers from misunderstanding the capabilities of catchy, marketing-driven branded names for popular systems.

Methodology

AAA conducted naturalistic driving evaluations on a 24-mile loop on a limited-access toll road in Southern California. The testing used four popular makes and models paired with a leading safety spotter vehicle. All test drivers and spotters were AAA researchers. Each simulated driver distraction test ran ten minutes and used three methods:

• Hands off the steering wheel, head up facing the road but gazing down.
• Hands off the wheel, head and gaze aimed down to the right toward the center console.
• Active circumvention or attempting to “beat the system” through a variation of gaze/head placement and periodic steering wheel input.

AAA selected four vehicles for testing, choosing two of each driver monitoring design type, camera-equipped and input from the steering wheel. The vehicles were as follows:

• 2021 Cadillac Escalade with “Super Cruise™” using a driver-facing infrared camera
• 2021 Subaru Forester with “EyeSight®” and Driver Focus using a driver-facing infrared camera
• 2021 Hyundai Santa Fe with “Highway Driving Assist” (steering wheel)
• 2020 Tesla Model 3 with “Autopilot” (steering wheel)

The vehicles were procured directly from the manufacturer or specialty rental fleets. AAA chose the test route due to its consistent traffic volume moving at or near the posted speed limit of 65mph to make the testing as safe as possible. Please refer to the full report for methodology details, including specific testing equipment and the driving route.

Active driving assistance, which is classified as Level 2 driving automation on SAE International’s scale of Level 0 to Level 5 and includes lane-keeping assistance and adaptive cruise control, provides the highest level of automated vehicle technology available to the public today. It also means that constant driver supervision is required. Most drivers will only interact with vehicle automation through these systems, which according to previous AAA research, are far from 100% reliable.