However, it’s not perfect.
With drive assistance features becoming standard in many vehicles, it’s good to remember they’re not all the same. Some work better than others, and the Insurance Institute for Highway Safety is devising a series of tests to evaluate these systems in various driving situations. The focus of the tests is Level 2 “autonomy” as defined by SAE International, which includes adaptive cruise control (ACC) and active lane-keeping (ALK).
In IIHS’s research, the company tested five vehicles: 2017 BMW 5 Series with "Driving Assistant Plus," 2017 Mercedes-Benz E-Class with "Drive Pilot," 2018 Tesla Model 3 and 2016 Model S with "Autopilot" (software versions 8.1 and 7.1, respectively), and 2018 Volvo S90 with "Pilot Assist.” The Tesla Model 3 performed best through the bevy of tests – however, it wasn’t perfect.
The cars were put through four different scenarios to test their ACC. The first involved driving at 31 miles per hour toward a stationary vehicle with ACC off and autobrake turned on. Only the two Teslas failed, hitting the stationary target. The same test was then performed with ACC on, and the Tesla Model 3 slowed with gradual decelerations. All vehicles passed this portion.
A third scenario had the cars follow a lead vehicle that slowed to a stop and then accelerated. Every car performed well in this test. The final test had the test cars follow a lead vehicle that changed lanes to reveal a stationary vehicle in the test vehicle’s path. The vehicles had about 4.3 seconds before colliding with the stationary vehicle. However, all the test cars performed well with none of the vehicles striking the stationary vehicle.
Where the Tesla Model 3 truly outshined its competition was in the hill and curve tests for ALK. Here, the IIHS conducts six tests on three different sections of curved roads. Only the Model 3 stayed within its lane through all 18 trials. To test how the ALK of all five vehicles performed on hills, the IIHS mapped out a course on three hills with different slopes, running six different tests on each hill in each vehicle. Here, the Model 3 had just one deficiency, touching the centerline once in 18 tests.
The Model 3’s competitors had various levels of success with the ALK tests. The BMW, Mercedes, Model S, and Volvo all went over the centerline during both the hill and curve test, with the Model S crossing the most at 12 times when being tested on the hills. The Volvo crossed the line the most at eight times during the curve test. Some of the vehicles, such as the 5 Series, E-Class and S90 had the ALK system disengage during the tests, with the 5 Series system disengaging the most.
As these systems infiltrate new cars, drivers need to understand their limitations and the differences between makes and models. It will be up to agencies such as the IIHS and the National Highway Traffic Safety Administration to design tests that both inform consumers and keep them safe because driver assistance features aren’t going anywhere. However, it’ll be years before these systems are foolproof.
"We're not ready to say yet which company has the safest implementation of Level 2 driver assistance, but it's important to note that none of these vehicles is capable of driving safely on its own," David Zuby, IIHS chief research officer, says in the study. "A production autonomous vehicle that can go anywhere, anytime isn't available at your local car dealer and won't be for quite some time. We aren't there yet.”