The freight rail network in the US is very robust and generally runs at or near capacity. About twice as much freight, percentage-wise, moves by rail in the US

The freight rail network in the US is very robust and generally runs at or near capacity. About twice as much freight, percentage-wise, moves by rail in the US as in Europe (though this varies somewhat depending on whether the denominator is tons of product or dollar value; there are more bulk commodities shipments, e.g. coal and grain, within the US that are almost invariably shipped by rail). Many people fail to appreciate how much stuff is shipped by rail in the US, because it is largely raw and intermediate goods traffic, and also perhaps because they extrapolate the poor state of US passenger rail and assume that freight rail is somehow equally poor (it is not; in fact some of the problems with US passenger rail stem from the system being optimized for freight). I would expect there to be more raw interest in automated or semi-automated trucking in Europe than in the US, and perhaps there will be once the technology is proven and regulatory issues are ironed out. OTOH, I'd imagine you are correct that the interest in driverless passenger cars is related to the car-centricity of US cities and the lack of public transport options. Many people are seemingly looking to "driverless Uber" as the solution for congested cities, ignoring the established solutions to the same problems, because they aren't things the private sector can deliver.