alt Hacker NewsAbsent more precise information, this is a statistical negative mark for Waymo putting their child pedestrian injury rate at ~2-4x higher than the US human average.
US human drivers average ~3.3 trillion miles per year [1]. US human drivers cause ~7,000 child pedestrian injurys per year [2]. That amounts to a average of 1 child pedestrian injury per ~470 million miles. Waymo has done ~100-200 million fully autonomous miles [3][4]. That means they average 1 child pedestrian injury per ~100-200 million miles. That is a injury rate ~2-4x higher than the human average.
However, the child pedestrian injury rate is only a official estimate (possible undercounting relative to highly scrutinized Waymo miles) and is a whole US average (operational domain might not be comparable, though this could easily swing either way), but absent more precise and better information, we should default to the calculated 2-4x higher injury rate; it is up to Waymo to robustly demonstrate otherwise.
Furthermore, Waymo has published reasonably robust claims arguing they achieve ~90% crash reduction [5] in total. The most likely new hypotheses in light of this crash are:
A. Their systems are not actually robustly 10x better than human drivers. Waymos claims are incorrect or non-comparable.
B. There are child-specific risk factors that humans account for that Waymo does not that cause a 20-40x differential risk around children relative to normal Waymo driving.
C. This is a fluke child pedestrian injury. Time will tell. Given their relatively robustly claimed 90% crash reduction, it is likely prudent to allow further operation in general, though possibly not in certain contexts.
[1] https://afdc.energy.gov/data/10315
[2] https://crashstats.nhtsa.dot.gov/Api/Public/Publication/8137...
[3] https://www.therobotreport.com/waymo-reaches-100m-fully-auto...
[4] https://waymo.com/blog/2025/12/demonstrably-safe-ai-for-auto...
Replies
I don't think I'd want to take much from such a statistical result yet. A sample size of 1 accident just isn't enough information to get a real rate from, not that I want to see more collisions with children. Though this is also muddied by the fact that Waymo will most likely adjust their software to make this less likely, and we won't know exactly how or how many miles each version has. I'd also like to see the data for human incidents over just the temperate suburban areas like Waymo operates in.
> child pedestrian injury rate at ~2-4x higher than the US human average.
If this incident had happened with a human driven vehicle would it even have been reported?
I don't know exactly what a 6mph collision looks like but I think it's likely the child had nothing more than some bruises and if a human has done it they would have just said sorry, made sure they were ok, and left
I don't think this comparison is meaningful given the sample size of 1 and the differences between the between your datasets. The standard error margins from the small sample size alone are so large that you could not reasonably claim humans are safer (95% CI for Waymo is about 1 per 20 million miles to 1 per 8 billion miles). Then there are the dataset differences:
1. The NHTSA data is based on police-reported crash data, which reports far fewer injuries than the CDC reports based on ED visits. The child in this case appeared mostly unharmed and situations like this would likely not be counted in the NHTSA data.
2. Waymo taxis operate primarily in densely populated urban environments while human driver milage includes highways and rural roads where you're much less likely to collide with pedestrians per mile driven.
Waymo's 90% crash reduction claim is at least an apples-to-apples comparison.