Passengers per Vehicle per Day (ppvpd)
This is an indicator of the level of passenger use of each vehicle in service. It is influenced not only by total passenger demand but also by vehicle capacity, length of operating day, length of route, average distance traveled per passenger, the extent to which demand varies between peak and off-peak periods, and the kilometers operated per bus per day.
The route structure has a significant influence: for example, a route network comprising a large number of short routes requiring passengers to interchange several times during the course of a journey will result in a much higher ppvpd figure than a more complex route structure providing a greater number of direct links. Similarly, the average passenger’s journey will tend to be longer in a large city than in a small town, so the ppvpd figure will be lower in the former than in the latter.
Therefore very wide variations are possible, and the reasons for these must be understood. For example, buses on long distance services may carry full loads of passengers from one end of the route to the other, with no intermediate traffic; if only one trip is made per day, ppvpd will be approximately fifty for full-sized buses. Large buses on city services, making several trips, with a high turnover of short distance passengers, may carry up to 3,000 ppvpd. Passenger-kilometers, however, could be the same in each case: if, for example, the average distance traveled by long distance and short distance passengers were 120 kilometers and two kilometers respectively, the number of passenger-kilometers would be 6,000 in both cases.
As with other indicators, it is normally most appropriate to base this calculation on the number of buses licensed. On this basis, and assuming that approximately 85% of the fleet is operational, the normal range for buses with a capacity of 80-100 passengers on city services is between 600 and 1,800 ppvpd. For articulated buses with a capacity of between 150 and 200 passengers a normal range would be between 1,500 and 2,500 ppvpd.