First I divided the I wanted to study into several segment. I identified the end points of the various segments by traveling the bus route in a car and nothing the distance from the start point. For 23 school days,I used a stopwatch to record the time the bus took to cross the endpoint of each . I stopped the watch whenever the stopped and children boarded to eliminate boarding delays.
I computed the average travel time and the variation for each segment. Since the segments were not of equal distance,I estimated the time per kilometer for each segment before comparing them.