Not all adaptive cruise control and road maintenance systems are created equal. That should be obvious, but if not, recent tests by the Insurance Institute for Highway Safety will prove it. On Tuesday, The IIHS publishes the results of some roads and track test with many different ways of the vehicle, measuring how each one is able to stay within its path around corners and hills.
“We hit on situations that our staff had identified as areas of concern during test drives with the Level 2 systems, then used that feedback to develop road and track scenarios to compare vehicles to,” Senior Research Engineer IIHS Jessica Jermakian said. By “level 2,” Jermakian means vehicles capable of steering, braking, and accelerating on their own but only with a human driver behind the wheel responsible for providing situational awareness.
The vehicles (and advanced driver assistance systems) that the IIHS tested were the 2017 BMW 5 Series (Assistant Driver Plus), 2017 Mercedes-Benz E-Class (Pilot Drive), 2018 Tesla Model 3 (Autopilot 8.1), 2016 Tesla Model S (Autopilot 7.1), and 2018 Volvo S90 (Pilot Assist). The IIHS notes that each has been rated highly for their automatic emergency braking (AEB) systems. Several track tests are used to establish how each system copes with avoiding collisions with a stationary car, then a road test is also carried out to understand the real-world behavior in traffic and how the car each maintains a good position within its path.
Automatic cruise control and braking for stationary vehicles
In the first series of tests, all cars successfully avoided a collision when head-on with a stationary car while traveling at 31mph, with the Volvo braking most aggressively, similar to its AEB activation. (Interestingly, both Teslas hit a stationary car in the AEB test.) Interestingly, all cars avoided hitting a stationary object when following a lead car that suddenly changed lanes—a “cut-off” scenario. -out” is literally shown as being outside the public domain. coverage for advanced driver assistance systems (ADAS) in NHTSA’s investigation into a 2016 Tesla crash in Florida.
The performance isn’t very good in the real world, unfortunately. IIHS found that, with the exception of the Model 3, each car had moments when it failed to stop for the car in front (which is why it is important for human drivers to always pay full attention to the road). Model 3 actually suffers from the exact opposite problem; instead of false walls it is sensitive to false positives, accidentally slowing down in 12 events, seven of which are for tree shadows on the road. While that’s probably annoying for the driver, I’ll gladly take a false positive over a false wall under these circumstances.
Lane kept helping
The five cars were also tested to see how they handled the auxiliary functions that worked on the curves with three different radios. Once again, the Model 3 stood out: it was the only car to stay within its means every time the tests were repeated. The IIHS notes that BMW, Volvo, and Mercedes-Benz do not provide “enough steering input on their own to stay in their lane, often requiring the driver to provide additional steering to successfully navigate on the go.”

IIHS
Real-world driving with curves and hills hits all other vehicles except the Model 3, as you can see from the table above. BMW’s system seems to be the most polished by the elevation changes, although the slopes still let the Model S stray off its course quite often. However, it is very important to note that the IIHS says it is not yet ready to begin officially consumer rating the performance of these different systems. For that, you need a lot more testing.
We will certainly welcome when more of that data becomes available. On several occasions, readers have asked us to put together a group test of different ADAS implementations, but it’s such a fast-paced project that requires a lot of time and resources if you want to do it well.
Perhaps the best effort so far is the one made by our friend Alex Roy on The Drive back in 2016. But two years is a long time at this point. Even within an OEM range, it is possible to find a very different performance between different models, and the older the system, the less powerful, by and large. In the meantime, whether you drive a Tesla or a Toyota, if you are going to use a consistent vehicle and keep the road, just remember: it is always. his work to keep your eyes on the road.