Charging time. A truck/driver doesnt remain stopped. It drops a trailer and picks up another. And a truck needs charging on the open road where there just are not any charging stations. But a trailer remains parked at a loading bay for hours, a commercial facility where installing chargers makes sense. A trailer therefore has more oppertunity to charge than a truck.
And if a company wanted to, parking a trailer to let it charge is far cheaper than paying a truck/driver to sit around.
And if a company wanted to, parking a trailer to let it charge is far cheaper than paying a truck/driver to sit around.