I frequently hear people describe cycling in the city as dangerous, frightening, and nerve-wracking. Frightening, yes, Nerve-wracking, absolutely. But cycling, in and of itself, does not pose any particular dangers. Cycling simply makes you vulnerable to the really dangerous traffic on the streets: the two to nine-tonne steel bombs, otherwise known as cars, SUVs, and trucks.
We frequently conflate danger and vulnerability, but when we do so, we blur an important moral distinction. I behave dangerously when I unleash forces I cannot properly control of cope with, whether I or others will suffer the worst consequences. I make myself vulnerable when I go without protection from dangerous things that other people do. When I speed, as I unfortunately have done, on the highway, I behave dangerously, to myself and others. When I ride my bicycle, I make myself vulnerable, but I do not behave dangerously.
So when someone tells you they find cycling in the city frightening, they should. Going without a steel cage into the unpredictable whirl of our streets frightens me. But that doesn't make my choice dangerous. Sometimes our most responsible choices make us very vulnerable.