I've lived in Somerville for over 40 years and have visited even longer. The roads are more dangerous than ever.

With all the Vision Zero work, and earlier traffic safety progress, this would be surprising and disappointing if it were the case. Is it?

Somerville is an interesting city to look at because it was mostly built out decades ago. The last large change was bulldozing I-93 through in the late 1960s:

This makes fatality rates over time comparable in a way they wouldn't be if you were looking at a city that had expanded, contracted, or been seriously rebuilt.

I pulled accident date from the national Fatality Analysis Reporting System (FARS) which goes back to 1975. Here's what I see for the number of fatal crashes annually (code):

blue bars are annual counts; red line is a 10y centered moving average

Over the last 40y it's gotten about 3x better, though 2019 was a pretty bad year.

I'd also be interested in whether our roads are becoming more dangerous for pedestrians specifically. Is the decrease just due to airbags, crash testing, and cars becoming safer for their occupants? While pedestrian data in FARS only goes back to 1991, we can still graph what we have:

It does look like we're making progress specifically within pedestrian safety as well, though 2019 now sticks out even more.

(I'm being lazy here and charting "traffic accidents with a fatality and involving at least one pedestrian". The FARS data does make it possible to see whether it was a pedestrian that died, but this requires joining CSVs in a way that's a bit awkward. In the ones I've spot checked the fatality was a pedestrian, which is what you'd expect.)