How Tesla fared in test of driver-assistance systems

Anyone with assisted-driving functions in their car should still keep both hands on their car’s steering wheel, according to a new study.

The U.S. Insurance Institute for Highway Safety has released the results of its testing of several car models with assisted-driving features. The group said that while many of the vehicles’ systems performed well, there remain circumstances in which the systems may fail to live up to their promises.

The vehicles tested included the Tesla Model S and Model 3, the Mercedes E-Class, the BMW 5-Series and the Volvo S90. IIHS said it tried the cars out on both public roads and a closed testing track.

IIHS said the Tesla Model 3 did the best job of staying within its lanes during a series of tests of active lane-keeping systems. IIHS ran 18 different such trials, on both hills and road curves, and found the Model 3 stayed in its lane on all 18 curve trials and 17 of the trials on hills. The Tesla Model S remained in its lane in 17 of the curve trials, and five of the hill trials.

But, when it came to adaptive cruise control (ACC), a technology that sets a vehicle’s speed and distance from the vehicle in front of it, IIHS said the Teslas put in a mixed performance.

IIHS said that when the Teslas had their ACC systems turned off, automatic braking turned on and were travelling at 50 kilometres an hour, the Model 3 and Model S braked as expected, but still hit an inflatable target. However, when their ACC systems were turned on, the Teslas did not hit the test’s balloon target.

The IIHS report stressed that many of the instances in its tests were covered in the vehicles’ owner’s manuals, and that drivers need to keep in mind that their cars are not capable of driving on their own.