You can't do police chase in single player because the NPC that are fleeing crash in the first car in front of he and get stuck, very frustrating and the police also have 0 skill. They can`t even do a pit manuever.
and the worst part is is that when a ai attempts to race or flee from the player it bumps into other cars, which is terrible to see
They HAVE to be purposefully making the AI bad. Now sometimes the AI will drive into the wall and slowly inch around it like a blind guy trying to feel where the divider is on the highway with his bumpers