Autonomous trucks don't need stationary rest so you can halve your fleet number just from higher fleet utilization.

Battery powered trucks are also expected to have lower downtime for maintenance and overhaul, so you can shave off another 5%. Rebuilding an engine and gearbox is an expensive maintenance activity that is completely eliminated, along with brake servicing due to regenerative braking.

Once the charger situation is figured out, probably an overhead catenary and dedicated charging lanes to keep the trucks in motion while charging, the savings will be compelling.