I looked up, i.e. Chicago. There were double the number of homicides vs fatal car accidents. I don't pretend those can be compared 1:1, but I'll note when I took public transit it wasn't just the risk of being on the transit but also getting dumped out near areas that were violent assault / murder hot spots.

The public transit stations I rode in the eastern part of Cleveland would become or already were hood rat hangouts where I would routinely see vicious beatings. I eventually started biking, which was a bit safer, although still then someone tried to rob me at gunpoint when my bicycle got a flat near the public transit line. I finally moved to somewhere with no public transit and haven't dealt with such violent threats since. I learned public transit = robbery/gang express, get further away and you get further away from their getaway -- although many of them know not to 'shit where they eat' by doing it right on the train car. Another plus of getting off public transit was the ability to carry a weapon, in case some jackass tried it again.