With every passing year, cars are getting smarter. Semi-autonomous technology is very impressive, allowing vehicles to maintain a distance behind the vehicle in front, steer, or even brake to avoid collisions. But the reality is that these systems aren't foolproof, sometimes leading to catastrophic results.

Manufacturers are aware of this and fit semi-autonomous vehicles with driver monitoring systems, to ensure they are, in fact, paying attention to driving and their surroundings. But real-world testing conducted by the American Automobile Association (AAA) has found some systems are better than others, with driver-facing cameras besting monitors that measure steering wheel inputs. As we're aware, the AAA notes these safety preventions are not infallible: "A driver determined to cheat the system can defeat it."

Before releasing these results, the AAA met with carmakers to share its insight from the testing experience, recommending areas that could be improved.

To test the effectiveness of driver-monitoring technology, the organization tested four vehicles in real-world conditions; two equipped with driver-facing cameras and two with steering wheel monitors. A Cadillac Escalade equipped with Super Cruise and a Subaru Forester with EyeSight were used to study camera-based systems, while a Hyundai Santa Fe with Highway Driving Assist and a Tesla Model 3 with Autopilot were used to evaluate steering wheel monitors.

Each vehicle was put through its paces on a 24-mile loop on a Southern California road. Driven by AAA researchers, each test ran for 10 minutes and used the two aforementioned technology types with drivers actively trying to outsmart each system through intermittent steering input and head/gaze placement.

It found camera-based systems to be superior, alerting disengaged drivers some 50 seconds sooner and proved more persistent than those detecting steering wheel movement. This was true for the systems whether the driver was looking down or at the center console.

On average, "the percent of time test drivers were engaged was approximately five times greater for camera-based systems than for steering wheel systems." The latter required minimal input to prevent alerts, allowing up to 5.65 continuous minutes of distraction. Traveling at 65 mph, this is the equivalent of over six miles of disengaged driving. Scary.

But it's not all good news for camera-based systems. The superior monitoring system still allowed for 2.25 minutes of distraction over the 10-minute test. "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," reports the AAA.

"The key to a safe active driving assistance system is effective driver monitoring that can't be easily tricked," said Greg Brannon, director of AAA's automotive engineering and industry relations. "Vehicle technology has the potential to improve roadway safety, but the last thing we want is ineffective features in the hands of uninformed or overconfident drivers."

Overall, the organization recommends camera-based driver monitoring systems over steering wheel monitoring but notes further refinement is needed.

While semi-autonomous driving has myriad safety and convenience benefits, the reality is that driver monitoring systems aren't strong enough to circumvent the potential dangers that could be brought on by the driver. Until these kinks are ironed out, semi-autonomous technology will always be shrouded in a cloud of possible risk.