1000 m ahead a group of 5 people walks the pavement along the road. Should the car slow down so that it can stop on time if they suddenly try to cross the road?

1000 m ahead a group of 5 people walks the pavement along the road. Should the car slow down so that it can stop on time if they suddenly try to cross the road? If so - self-driving cars will be going much slower than manualy driven cars most of the time, which will probably hurt adoption. I would like this to be the case, but I guess car companies will agree to some compromise to speed up adoption, and corner cases will be there. Should the software ignore them, or plan for them (= "planning to kill you").