They always say it's about safety, but in the end, real safety takes a back seat to revenue. Just look at the red light cameras. If they really wanted safety, they'd lengthen the yellow lights by a second or two (or add a second of dead time, where all lights are red) so that traffic could clear the intersection, but that would mean a loss of $.
Same in Dallas. The city of Dallas put up redlight cameras and issued tickets to red light runners. Drivers quit running the lights, so the revenue dropped. Then the city decided they coudn’t afford the maintenance on the cameras and turned them off. Go figure.