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Comment by hammock | Hacker News Reader

Per government data, San Francisco Muni bus pedestrian fatalities are roughly 2 per 100 million miles, while general motor vehicle pedestrian fatalities are a fraction of that, about 0.4 per 100 million miles.

Even if you limit strictly to surface streets, Muni buses remain 2-3x more likely to be involved in a pedestrian fatality per mile driven than general vehicles

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Can you cite a source for that one? Of the 25 fatalities in sf in 2025 all but two were someone driving a car, truck, or van.

Of the two others, one was a scooter operator striking and elderly person, and then the other was an elderly person on a mobility device swerving out of the way of pedestrians crossing against the light. Zero bus accidents involving pedestrian fatalities.

I believe that their was one bus fatality this year, but of 12 total, I haven't looked up the causes of those accidents yet but I'd guess that the majority of them are going to be caused by drivers as well.

They also tend to be carrying 5-25x more people than cars, so there are far fewer of them. They also tend to be driving in the city on the busiest streets, whereas arbitrary cars are more often driving on vacant streets and highways.

so try the comparison using (miles x flow) instead of miles if you're measuring safety, and if you're measuring worthwhile risk, multiply that by passenger-miles. If you're talking about pedestrian safety, you'll probably have to square the (miles x flow) because pedestrians are also less safe the busier a street is.

I was directly responding to a comment arguing that bus drivers were more adept at avoiding pedestrian killings than SUV drivers. Unfortunately extra training cannot change the physics of a 40,000 pound hunk of metal.

If you look at passenger-miles (pax in the bus) or some other metric the rate might be lower for buses but that’s not relevant to what I responding.

How about by hour?

Cars are not causing a lot of pedestrian fatalities driving on the freeway between Nowhere and Flyover, but they rack up the miles there.

I provided the surface streets only metric, which eliminates freeways

That makes sense, given that the median car mile probably isn’t in a dense urban core. The more accurate comparison would require us to know pedestrian fatalities per mile in urban areas.

This is for SF, so 100% urban for both bus and vehicle data

That’s fascinating; like others, I’d love to see the source data.

Buses are also more massive so more likely to cause serious injury in an accident. They can't stop as fast as a car/bike /etc. But that's also why they seem to move more slowly, takes them longer to accelerate, which one would think might give others an advantage to avoiding them.

What matters is not the number of miles.

What matters is the number of people killed.

A steady miles per fatality means more people die as more miles are driven.

And more miles driven is the trend.

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