You just need electric trucks with one pair of drive wheels powered by electric motors. Maybe more if you want more traction, but an 18-wheeler doesn't need 9

You just need electric trucks with one pair of drive wheels powered by electric motors. Maybe more if you want more traction, but an 18-wheeler doesn't need 9 drive wheels. It might have 8, if the tractor has two drive axles with dual tires. In practice you could just replace the engine with an electric motor and keep the rest of the drive train the same, as is done on many EV conversions now. If the system is on the major roads, then that's where the major energy is being used. If you're stuck somewhere in traffic or waiting to load/unload, you're not actually using much energy. Honestly I'd be okay with the energy being unmetered. I think the cost to society of CO2 emissions is probably greater than the cost of supplying trucks with free energy would be anyways, so I think it's probably a net win for society to have it as a free service. But there are also ways to charge for it if we wanted to go that route. Paying for the energy is a non-problem, you'd just need to decide on a policy. Ideally in the U.S. this would be installed on interstate highways, at regular intervals. Maybe 5 miles on, 20 miles off or something like that. The overhead lines don't need to be everywhere, they just need to be in enough places that cross-country shipping is possible, and local shipping between major cities is possible.