Police responding to the actual crash scene, useful. Police report filed after the fact, only if there's some need for said report. And not all injuries are immediately apparent. 3 1/2 years ago I got a first-person view of what it would be like to be on the receiving end of a PIT maneuver courtesy of a woman who didn't look adequately. (Yes, when you looked left the road was empty--I saw that also and turned into that empty spot the block before you!) At the time the only injury I was aware of was a very minor scrape, not even worthy of a bandaid. Later I discovered a pulled muscle--it only hurt when I did certain things.

I also used to know a woman who thought it was nothing more than a fender-bender, went to the doc a couple of days later because her neck was bothering her. Doc sent her straight to the hospital--incomplete cervical fracture, one wrong move and she could have dropped dead.