The way I factor in safety is by choosing my routes. Minneapolis is wonderful for this. Depending where you live and work you may be able to bypass roads completely.
In any case though, beyond reasonable precautions such as helmets and defensive riding, I'm not going to run statistics to figure out the safest way to live my life. Bicycle commuting in general isn't something I consider an extreme risk. I'd certainly rather take my chances at injury doing a real activity than become an invalid at age 60 because I never got any exercise—because if I have to go to a gym to get exercise "safely" it ain't gonna happen.
In any case though, beyond reasonable precautions such as helmets and defensive riding, I'm not going to run statistics to figure out the safest way to live my life. Bicycle commuting in general isn't something I consider an extreme risk. I'd certainly rather take my chances at injury doing a real activity than become an invalid at age 60 because I never got any exercise—because if I have to go to a gym to get exercise "safely" it ain't gonna happen.