[JackMcMack]

This actually sounds doable if the battery charging trailer is self driving (and self docking). You would lose only minimal time slowing down for the docking/undocking. Easier to test on select pieces of highway with predictable self driving conditions. And the highway gives you space and time for charging, when you need it most for long trips.

[Johnny555]

We're still far from having self-driving cars, I don't think we'll have self-driving battery trailers running around the highways anytime soon. And you've just more than doubled the cost of these battery trailers by putting motors and control systems in them.

My gas powered car gets around 300 miles of range before the fuel light comes on and I need to make a 10 or 15 minute stop to refuel. I think I could survive with an EV that gets 250 miles of range between charges (300 mile rated range, assuming 80% charge) before needing a 20 minute charge stop, I need to stop and stretch my legs, eat, or use the restroom more often than that.