Yes, as Tommy says, these graphical representations of the incidence of collisions fail to convey the fact that the total number of trips made by pedal cycle is so much higher than the number of collisions that the likelihood of crashing is very small indeed.
As for main streets, they are the streets that carry the highest flows of traffic, and they are where most cyclists go. It's therefore never surprising to find the highest number of collisions there.
Yes, as Tommy says, these graphical representations of the incidence of collisions fail to convey the fact that the total number of trips made by pedal cycle is so much higher than the number of collisions that the likelihood of crashing is very small indeed.
As for main streets, they are the streets that carry the highest flows of traffic, and they are where most cyclists go. It's therefore never surprising to find the highest number of collisions there.