Because then the car would break every time anyone approached the car from an angle (which is constantly). Think every intersection ever, every time driving near a sidewalk ever. The car would be herky/jerky as crap.
They should have had it set to spike the breaks once collision was imminent though, that's (maybe) the biggest programming omission here.
They should have had it set to spike the breaks once collision was imminent though, that's (maybe) the biggest programming omission here.