It's complicated: the presence of a red-light camera decreases the rate of right-angle crashes, but increases the rate of rear-end crashes - people about to miss the light will stomp on their brakes instead of scooting on through. It's not clear there is any benefit, other than to the profits of the private companies typically contracted to operate the cameras.

https://www.chicagotribune.com/suburbs/lake-county-news-sun/...