When travel speed increases by 1%, the injury crash rate increases by about 2%, the serious injury crash rate increases by about 3%, and the fatal crash rate increases by about 4%. The same relation holds in reverse: a 1% decrease in travel speed reduces injury crashes by about 2%, serious injury crashes by about 3%, and fatal crashes by about 4%.
https://dc.streetsblog.org/2010/02/24/fact-checking-the-toyota-hearing-lower-speed-limits-increase-safety/oldId.2010022500053781
Biking in Baltimore