Okay, so there's a whole bunch of hullabaloo about not being able to do long-distance trucking because the tractor units don't have the range. Well, there's a simple solution to that.
Most semi trailers have a flat deck from hitch to rear wheels, with a simple ladder frame underneath to hold it up. There's a couple of legs, and a (comparatively) tiny air tank to boost the rear brakes, but aside from those and a couple of wires to power the lights, it's all empty. Some even have plastic "air dams" or metal side rails for aero or safety. So why not put a battery pack under there, using the dead space? Give it it's own charger as well, and you can have the trailers charging while they're being loaded and unloaded, or stored overnight, and it means they can provide the extra power needed to compensate for their added load. It would mean that the driver has to connect an extra cable when hooking up, but as they already have to handle air lines for the brakes and a lighting connector, one extra cable wouldn't be a problem.
You could also replace the air brakes on the trailer with electric motors for regenerative braking (probably excessive, but it's an option). It would add weight to the trailer, so you couldn't load as much into them, but that is potentially a small drawback considering.
