Driving by increasing the speed from 0 km/h and 80 km per hour for 1 hour and then. So a constant driving speed of 80 kilometers per hour, 1 hour, and then driving back the starting point in about 2 hours.
Driving by increasing the speed from 0 mph to 80 mph in the first hour and then drove with constant speed of 80 km per hour for another one hour, and then drive back the start time in two hours.