When a driver is running late, the system finds another

Traffic happens. The old fix was a customer calling to ask where the car is, then a scramble to find a replacement.

Now the system watches each driver's arrival time on the way to a pickup. If a driver is going to be late and another driver can get there sooner, it offers that driver the job. If they accept, the job moves over and the first driver is released.

The office is told what happened, after it has already been handled.