Same down here in Arizona, everything completed in 1 day.
The main holdup is the Step Vans, they could give them the Skills/PRETRIP as the others are taking the Written test. That would free up some needed time.
Here they test everyone at the same time, walk the course, then you are free to go to do as you wish. You can watch the driving portion but not the pretrip. Other States you are put in a corral with you den mothers and not able to see what is going on (which I feel is very fair). Like Ump said, who wants to be around a hot parking lot after completion. 1 day is just too much.