The road test starts with a scan tool on the vehicle. Watch all parameters while driving.
Do an engagement test, drive then reverse. Are they sharp and not harsh? Do this in the beginning of the test and throughout the test.
Next is the shifting. You want light throttle shifts, medium, and wide open throttle shifts. Do these shifts feel normal in all ranges? At a traffic light, check engagements again.
You must also verify lock-up is working. Sometimes this requires you to be on the highway with a scan tool to verify. Some lock-up systems are very soft and the only way to determine if lock-up is working properly is with a scan tool. This will also verify if any codes are set.