Space? Roads take up way more space than tracks.
Efficiency of cost? Roads are very expensive. Often more expensive per passenger mile than railroads.
Efficiency of energy use? Moving a 2000kg electric car around for 1 person is never going to be efficient.
Efficiency of through-put? Roads even with autonomous cars will never have the throughput of a train-line.
Also I think you significantly underestimate the cost of road building and maintenance.
Roads are indispensable and essential for last mile connectivity. No matter if trains and subways become 10 times more popular they will always exist in addition to the road infrastructure. Thus autonomous electric cars are a huge boon, its just common sense.
That depends on how you are defining efficiency (doesn't it always), an electric motor with a good battery backed by a good powergrid (nuclear/renewables) is about the most efficient solution to "one person going from Point A to Point B" in many ways, I'm in favor of public transport but even in a European country it can let you down.
Also in the future with electric self-driving cars I'd happily not own a car (I don't now) and just rent one as and when it's needed from a pool of cars, that would take cars off the road compared to now.
>Space? Roads take up way more space than tracks.
Highways can now be minimised to two tracks, the standard width of a vehicle, vibration reports can tell the councils where pothole repair is most needed.
>Moving a 2000kg electric car around for 1 person is never going to be efficient.
Car's are 2000kg in part to protect the driver, as crashes trend to 0 there's no reason they need to be so big.
>Roads even with autonomous cars will never have the throughput of a train-line.
Trains are rarely full. Cars can get smaller, we can mitigate traffic jams.
Eletrics cars are 2000kg because a the battery weighs a lot.
Trains get smaller too when it's not rush hour. France regularly runs one carriage trains the size of a bus.
Mitigate and smooth flowing aren't the same thing. On way to work I see cars backed up for miles. Doesn't matter if they're self driving or not when cars move bumper to bumper already.
