Tag Archives: Reed Kempton

The Tempe crash

The dashcam video in the recent Tempe crash which killed a woman walking across the street with a bicycle has now been released.

To me, it is quite clear that the human driver was dozing off or distracted and that the vehicle’s sensors failed to register that the pedestrian — walking with a bicycle broadside to the road, a very robust infrared and radar target, and crossing empty lanes before reaching the one with the Uber vehicle — was on a collision course. The vehicle had its low-beam headlights on when high beams would have been appropriate, the headlights were aimed low (probably a fixed setting), and the pedestrian’s white shoes don’t show in the video until two seconds before impact, that is, at a distance of about 60 feet at the reported 40 mph.

Braking distance is about 80 feet at 40 mph, and reaction time for a human driver adds about another 60 feet. An automated system with radar and infrared should have noticed the pedestrian sooner, had a shorter response time, and stopped the vehicle. Human eyesight is much better than a dashcam’s at night and the human driver might have seen the pedestrian earlier and avoided the crash if she had been paying attention. But also, the bicycle had no lights or side-facing retroreflectors which might have shown up much earlier and alerted optical or infrared sensors or a human driver, and the pedestrian somehow chose to cross an otherwise empty street at precisely the time to be on a collision course.

So, the human driver and vehicle’s sensors failed miserably. We can’t allow automated vehicles (and human drivers) to perform at the level shown in this video. We do need to make greater allowances for pedestrians, bicyclists, animals, trash barrels blown out into the road, etc.

Several people have offered insights — see comments on this post, and also an additional post with a description and history of the crash location.