Worth nothing that the article clarifies that this is in reference to driving — as in "nearly a quarter didn't feel safe on San Francisco's roads at all"
One would need to know how this compared to other cities. As someone who used to visit SF a lot (though rarely drove much in the city),I'm not sure how it's notably bad. Sure there are the hills. But with an automatic transmission, that doesn't really make a big difference. And it's mostly grid-ish. It's not a particularly easy city to drive in but compared to NYC, Boston, DC, Seattle, etc., I'm not sure how it's especially awful.
I love how "on the roads" is taken to mean the same thing as "driving a car", rather than the vulnerable road users outside of cars who are hurt and killed the most on SF streets.