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Status Report, Vol. 53, No. 4 | SPECIAL ISSUE: AUTONOMOUS VEHICLES | August 7, 2018 Subscribe

Why good headlights matter

Volvo XC90

The ability for drivers to see the road ahead at night — and other drivers and pedestrians to see oncoming vehicles, too — is an important area of IIHS research that may have come into play in Tempe.

About half of traffic deaths occur either in the dark or at dawn or dusk, and the proportion of pedestrians killed in low light conditions is even greater. It is crucial that drivers, whether human or machine, have a good view of the road at night to drive safely. That is the role of headlights, especially on roads without street lighting.

The Uber that struck and killed Elaine Herzberg had a variety of sensors to help it "see" the road and its surroundings. These included light detection and ranging (lidar) sensors, radar sensors and cameras. While lidar and radar sensors don't depend on ambient light to see, cameras, like human eyes, do.

The high-contrast video recorded by the Uber dash camera makes the road appear to be in almost total darkness. The pedestrian was wearing dark clothes, and the bicycle she was pushing didn't have side reflectors. There are streetlights along this section of road, but the crash site wasn't directly illuminated.

According to the NTSB preliminary report, Uber's lidar and radar first detected Herzberg 6 seconds before impact but didn't know what to make of her. It is possible that with better lighting the cameras could have helped confirm she was a pedestrian.

Velodyne Lidar Inc., which supplies the sensors Uber uses, says lidar was capable of detecting a pedestrian with a bicycle, but decisions about whether to brake or take evasive action were left to Uber's software.

The crash involved a specially outfitted 2017 Volvo XC90. Its headlights are rated poor because they don't provide sufficient low-beam light in IIHS evaluations. Good-rated headlights would have illuminated twice as much of the road ahead for an attentive driver. That means extra time to see the pedestrian and act to avoid the crash or lessen its severity.

Crash reports don't indicate whether the XC90's low beams or high beams were in use. The SUV has high-beam assist, which automatically switches between high beams and low beams, depending on the presence of other vehicles. Research shows drivers rarely turn on their high beams. High-beam assist ensures that they do.

"Headlights probably don't come to mind when you think of autonomous vehicles, but they are important safety equipment, and we intend to continue our evaluations to encourage automakers to improve them," IIHS President David Harkey says.

Uber crash shows risk of on-road testing

In the fatal crash of an experimental Uber vehicle, the company had disabled the SUV's pedestrian detection and automatic emergency braking systems.

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