Legal chalenges are this: the driverless EV ran over someone but what happens is that corporations (often) bribe the judicial parties not charging them with a hit & run even though the victims families want justice for their vehicles killing pedestrians. The only “prevention” is harm reduction (investing into technology that’s able to detect human presence & sensors that activate in pedestian heavy areas stopping the vehicle).
Usually, when it’s a EV (with no human driver behind the wheel): is it still considered a criminal offense if a driverless EV ran over somebody as it just continues driving? In that case it’s mainly rideshare companies (i.e. Uber, Lyft, DiDi, etc) face criminal liability. Regardless, the companies who dispatch EV’s are sued when their vehicles run over somebody and the EV didn’t stop whilst doing so.
We won’t get different laws for them until this happens enough to catch public ire, and we shout about it. Till then, the cops don’t care, and neither do the courts, or lawmakers. Our “justice” system exists primarily to keep we poors in line and to protect the rich.