Comment by usrusr
> It seems like when the cars are going slower -- and there are fewer of them -- there are fewer crashes
Yes, because the throughput of that fast, high density road is so much bigger. Subjectively it feels like it has something like 2x the amount of cars, and when we look at accident density we may very well correct by that factor, but in reality the difference in throughput is much bigger. Number of cars present at a given point in time x speed. That quiet road, it's close to having no car throughput at all compared to the big one, but it still sees the occasional accident.
Indeed, on the main road through my locale, I'd be passed by 100+ cars per minute. On my 30 minute commute to work, via side streets, I encounter maybe 10 to 20 cars total.
I consider car avoidance to be the #1 cycling safety measure.