Six out of 16 midsize cars have captured a superior rating for their pedestrian crash prevention systems after rigorous testing by the Insurance Institute for Highway Safety.

Specifically, the top performers included the Audi A4, BMW 3 Series, Mercedes-Benz C-Class, Nissan Maxima, Subaru Outback, and Volvo S60. Because they avoided collisions or slowed substantially in track tests, all of their systems earned superior ratings.

All six superior-rated vehicles reduced their speed dramatically in a series of six tests and in most cases avoided hitting the pedestrian dummy — eliminating or greatly reducing the risk of severe injury.

IIHS engineers deemed the Nissan Maxima — a non-luxury car on which pedestrian crash prevention is standard equipment for 2020 — the big winner. It aced all six tests and avoided hitting the pedestrian in all six scenarios.

Conversely, the Ford Fusion, Hyundai Sonata and Kia Optima earned no credit because they failed to slow significantly in multiple scenarios.

IIHS points out that automakers often roll-out the high-performing systems in more expensive luxury lines or as expensive options. That makes the superior rating of the standard systems on the Maxima and Outback all the more impressive.

Meanwhile, the C-Class, 3 Series and Chevrolet Malibu each offer two different pedestrian crash prevention systems.

On the C-Class, the optional system earned a superior rating, while the standard one snagged just a basic rating. On the 3 Series, the standard system surprisingly scored a higher rating of superior, while the more costly optional system earned an advanced rating. Both of the Malibu's optional systems — a camera only and a camera plus radar — garnered basic ratings.

IIHS tests performance in three scenarios: an adult pedestrian stepping into the street in the path of the oncoming vehicle with an unobstructed view, a child darting into the street from behind two parked cars, and an adult pedestrian near the side of the road in the travel lane, facing away from traffic. The two perpendicular tests are conducted at 12 and 25 miles per hour, and the test simulating a pedestrian walking in a parallel path to the vehicle is conducted at 25 and 37 mph.

In each of these tests, the system has 1 or 2 seconds to stop the car to avoid hitting the pedestrian dummy.