Automatic emergency braking systems have become a prolific safety feature on modern cars and for good reason. Around 7300 pedestrians were killed in the US last year, which accounted for almost a fifth of all traffic deaths in 2021.
Aimed at automating driver responses to pedestrians, these emergency braking systems generally function as intended, with 19 of the 23 vehicles in the Insurance Institute for Highway Safety study earning superior or advanced ratings in daylight. However, three-quarters of the fatal pedestrian incidents in 2021 occurred at night, and the new nighttime test of automatic braking systems showed weaknesses in the technology.
The history of pedestrian recognition and brake testing for new vehicles dates back to 2019, with the technology and an appropriate response being necessary for IIHS Top Safety Pick and Top Safety Pick+ ratings from 2020 and on. The nighttime test is very similar to the original daylight test, with two common pedestrian crash scenarios.
The specifics of the tests involve an adult crossing the road with the vehicle traveling at 12 mph and then 25 mph, as well as an adult walking along the road at the edge of the travel lane as the vehicle drives by at 25 mph and then 37 mph. The test is also conducted with both low beams and high beams, with scores being awarded based on the average speed reduction in five repeated tests.
Testing a range of 23 midsize cars, midsize SUVs, and small pickups led to curious results, with only a few models performing well. Notably, Nissan's new Pathfinder was the only vehicle to avoid collision in every test variable, earning the midsize SUV a superior rating by the IIHS.
The Toyota Camry and Highlander as well as the Ford Mustang Mach-E also received superior ratings, though these models were not able to fully avoid impact during the 37-mph parallel pedestrian test. Seven of the 23 cars tested, including the Honda Accord, Subaru Outback, and Hyundai Palisade, achieved an advanced rating, meaning none of these models could avoid impacts in the 37-mph parallel test.
Basic-rated vehicles were able to avoid a collision at low speeds but struggled to slow down effectively in the 25-mph and 37-mph tests. Volkswagen's midsize SUV lineup earned a basic rating, as did the Mazda CX-9 and Ford's Maverick and Ranger trucks.
Vehicles that earned no credit slowed marginally or not at all before hitting the dummies in all testing scenarios, with four models receiving this score. Curiously, manufacturers that scored high with some models were also found at the bottom, with the Toyota Tacoma, Nissan Altima, and Honda Pilot receiving the no-credit rating.
"As we expected, most of these pedestrian AEB systems don't work very well in the dark," says IIHS President David Harkey. "But it's clear automakers can rise to this new challenge, as Ford, Nissan, and Toyota each earn superior ratings for some models."
The AEB systems are actually very effective, with data from the IIHS showing that equipped vehicles have reduced pedestrian crashes by more than a quarter on lit roads, but that it is still a fledgling technology with a need for refinement.
Eight of the 12 vehicles that earned basic or no-credit ratings in the nighttime tests were deemed as superior or advanced during the day, meaning these systems are effective under a controlled set of circumstances. Driving is never a fully controllable act, however, and the data confirms that dark roads nullify the statistical pedestrian crash reduction on AEB-equipped vehicles.
Harkey said it is especially discouraging that many crossovers, SUVs, and trucks scored poorly, considering these vehicles are larger and exponentially more dangerous to pedestrians. Advanced driver-assistance systems have improved pedestrian and cyclist safety overall, but the design of the vehicle itself plays a larger role in the outcome of crashes.
Even so, these emergency systems are a welcome addition to the world of roadway safety, and the need to tweak complex systems is constant. Manufacturers like Toyota, Nissan, and Ford have proven that the software basis for a widespread advancement is possible, though that push forward is more likely to come at the demand of regulators than from manufacturers directly.