quarantine 'em

Or, heck, raining? Big puddles everywhere. Which ones do you drive through, which do you drive around? Can you even detect them properly?

It's a single-track road with passing places. How does a self-driving car decide whether to back up?

Can your self-driving car follow a sequence of "Diversion" signs? Obey dynamic speed limits? Pull over to let emergency vehicles pass?

Handle horses? Safely overtake tractors? Follow a road just from the lane markings (no GPS, no map)? Follow a road without lane markings?

Wave someone in? Notice that someone else has waved you in? Read the sign which says which hours the bus lane is in operation?

Can your self-driving car obey arbitrary road signage written in natural language and intended for humans? Obey hand signals from police?

Navigate a car park, where all the laws of traffic fold in on themselves? Identify and select a disabled space when appropriate?

Any human driver who can't do any of these things is a danger to themself and others, obviously, and should stay off the roads