I never ride with music, never will, never would. I'm already stressed enough with cars not seeing me and all, not gonna add to that.
I always run with music except a few times in winter when snow removal is not ideal. Otherwise, for the roads I take, there is very little concern for me for cars. Except a few idiots not looking both ways when getting out of driveways (music or not would make no difference for these, and I am not well trained in spotting said idiots). I do sometimes very long runs (50+ km), and after 4h, music often is necessary to keep me going... I mean, you get to a point where sometimes you'd rather be home sipping a beer, so music either cheers me up to continue or keeps my mind off those thoughts, I dunno...
I always run with music except a few times in winter when snow removal is not ideal. Otherwise, for the roads I take, there is very little concern for me for cars. Except a few idiots not looking both ways when getting out of driveways (music or not would make no difference for these, and I am not well trained in spotting said idiots). I do sometimes very long runs (50+ km), and after 4h, music often is necessary to keep me going... I mean, you get to a point where sometimes you'd rather be home sipping a beer, so music either cheers me up to continue or keeps my mind off those thoughts, I dunno...