Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

This implies that the only road users are cars and that vehicle volume is fixed. Factors like vehicle speed, modal mix, lane widths, and parking geometry all affect the safety profile of a street. "Cars passing by" is too lossy a metric to be relevant. Decreasing vehicle volume is always an option.


It is definitely not too lossy to be valuable.

Imagine a town that has 100 cars in it and 10 traffic deaths per year vs a town that has 10,000 cars in it and also 10 traffic deaths per year. Both towns have the same population. Without any sort of normalization the towns look the same, but clearly very different things are going on in those scenarios and a per mile or per car or whatnot will help you identify that. Obviously it doesn't give you any sort of root cause but it is an indicator that a deeper investigation is needed.


Then just note the vehicle volume and don't divide your deaths by volume? When you divide your deaths by volume you're implying that there's some value in a metric that amortizes deaths by vehicle volumes. Automobile volume is just one of several variables and simplifying this equation is why the US has a much higher traffic crash and fatality rate than any other developed country in the world.


What is the point of "noting" and not dividing? Sure, you can normalize by all sorts of different metrics. That doesn't mean you shouldn't normalize at all.




Consider applying for YC's Fall 2025 batch! Applications are open till Aug 4

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: