Available in Europe since 10 yrs ago. Not a rare sight, but not super-popular either.

Also https://en.m.wikipedia.org/wiki/Citro%C3%ABn_Ami_(electric)

With small cars in a city core these cars rarely go faster than 40 mph and on average about 30mph with traffic lights so you don't need the separation that you would want on a freeway. Several vehicles like this are already available or under development. I suspect that a Smart Car would come very close to meeting this spec already.

   > Honest question: wouldn't tipping be a major problem for half-width cars? And the amount of space needed between cars wouldn't go down much, so if you need at least 4 feet of clearance on either side, and your lane is 5 feet wide, your cars can only be 1 foot wide. This explains why most vehicles thinner than a car are motorcycles or electric scooters. 

1. Trains derail, crash, etc.

I live in a city that's a rail hub. We probably have a derailment every couple years even with annual rail/rail bed maintenance. They will fix the rail, the roads around it, and have everything back up and running in less than 2 days. You spill some diesel and it sucks to clean up. You spill Li and you walk into "environmental disaster."

2. Money. When it's cheaper, then they'll get serious.

To the last point it's similar to fleet vehicles for large fleets. You see a lot of pledges to go all-electric by 20XX. That's because replacing a fleet requires a TON of capital already, and fundamentally changing the vehicles is an order of magnitude higher.

Think about a delivery hub like the post office. They have a network already established for purchasing gasoline, delivering it, local storage, refueling process, etc. They have operations built around it.

You now likely have to have parallel infrastructure for electric, which means negotiating major power consumption with each local power company, purchase of new or adjacent land, buildout, etc. Can you refuel in the same time window to not effect operations? If not, can you shift operations without impacting customer experience?

Now, you will see companies deploying all-electric in niches, especially when it opens up new market opportunities. Those tiny urban vehicles could enable vehicles to go where they could not before, reducing time spent walking. And that might have a shorter timeline than autonomous drones that don't run old ladies over.

I think even more than cruise ships and freighters, the biggest all-electric vehicle impact would come from all-electric airplanes. They still haven't gotten off of leaded fuel (see #2). The emissions there are massive.

But I think #1 will be a barrier there too. And the bureaucracy will slow it way down just like it did with unleaded jet fuel, which exists now, but is essentially unused.

And I guess a theme I'm coming up with is that electric is cool and all, but won't impact big % points of emissions until it's adopted by cargo, not human transport.

And cases like trains and large ships that are electric, but fuel the local electric with local power generation bring up the other big point: How would we even begin to power cargo? It's orders of magnitude more massive than consumer vehicles and it's growing so fast that supply can't meet demand.

Anyway, whatever. I know enough to be dangerous but not enough to be an expert on any of this, and I'm rambling.

The battery concept is kind of dumb and a relic of IC engine thinking. For local urban journeys you could half-size the cars, provide common power, and add automated navigation to optimise density and efficiency.

Getting rid of batteries would hugely lower cost and weight.

Cross-country is a different problem, of course.

It provides a lot of flexibility.