The vast majority of accidents happen at intersections. At an intersection the faster you go the less time somebody in the cross direction has to see you, so speed makes you much less safe.
I've only seen one good study about this, and it was in Sweden where people drive very differently. That study suggested faster speeds do lead to more collisions or near collisions with cars.
But in the absence of more relevant and recent studies, I prefer to trust my own experience. I feel safer on a bike when I go faster because I'm moving at a slower speed relative to the cars more likely to hit me, and I can get out of the way of others more quickly.
