Is there a reason to believe that the police are trying to improve _traffic_ safety at this place? Perhaps they are trying to prioritize _pedestrian_ safety. That is, after all, why most no-turn-on-red signs are installed in California.
I had previously thought such rigid quotas were mostly urban legend until I saw the pattern repeat over and over with my own eyes.
1. Blocking 3/4 of one of the lanes under the bridge is a danger to both motorists and pedestrians. 2. I highly doubt there are many pedestrians at this intersection. It is basically an industrial park and the road dead ends a block away.