This is a contrived situation that never actually happens (even here in Manhattan, arguably the craziest place on Earth), but I’ll address it anyway. Where pedestrians are present, there’s never a sound reason for any vehicle operator to accelerate to speeds at which “stopping instantly” becomes the only logical (and physically impossible) option for avoiding a car-on-ped collision. Drive slowly, and suddenly a whole host of problems go away. NYC lowered its default speed limit from 30mph to 25mph a few years ago. This helped traffic move more smoothly and reduced the number of collisions involving pedestrians.