A 30 minute charge means each charger can service a maximum of 48 tractors per day, and realistically probably less than that. I wonder how many trucks fill at a typical diesel filling station per day.
Have you seen the demo's of "truck pack" batteries being removed from prime mover, transferred to charge station, replaced with already charged truck pack, all done with a mini fork lift? It's a 15 minute roll in / roll out kind of turn around. The game's not over and the big transport operators (eg: Rio Tinto mine fleets moving a billion tonne per annum, etc) are still doing the R&D pipeline and trialling pilots.
It should get adoption from companies big enough to run their own fleets (such as the mining company mentioned) but it won't be a suitable method for a good percentage of the long haul trucks in the States.
With that said, I would think chargers should be fine for a lot of those trucks if the infrastructure builds out for them. The drivers are already taking breaks every few hours by regulation, so they can top off rather than going from empty to full.