I disagree that it'll never happen but driverless 18 wheelers are the trolley problem writ large. The momentum from these vehicles is far more than a passenger vehicle so they have that much more capacity to cause damage and death. I think driverless taxis will happen first and then probably smaller delivery vehicles. I'd love for USPS to have automated delivery into standardized neighborhood boxes.

Once there's enough driverless vehicles large trucks can signal smaller vehicles things like "I need to turn right so please leave me room in the left turn lane to my right". Frankly the tow truck industry needs some disrupting. At least here in Houston they are the most dangerous lawless drivers on the road and need to go.

18 wheelers will drive to depot, cargo will be moved over to smaller self driving trucks and other delivery vehicles for the last mile. At least, that's the way it should be, even today without the automation. Huge trucks have no place in an urban environment.