Peak Occupancy Rate
The average peak hour occupancy rate at the maximum load point in the peak direction gives an indication of the adequacy of the service provided. If the average occupancy is less than 100%, there is surplus capacity within the system. If it is 100%, this may mean that the service is just adequate, but it is more likely to mean that there is unsatisfied demand, with passengers having to wait excessive periods before being able to board a bus.
There is a degree of subjectivity in determining what is a reasonable waiting time. Most passengers who are unable to board buses at peak times would, if they waited long enough, be able to board a bus during the off-peak, but for passengers traveling to work this is clearly unacceptable.
While excess capacity at peak times represents unnecessary expenditure, it is desirable that there should be a small amount of spare capacity, particularly in situations where demand is increasing. This will enable new demand to be accommodated, and potential new passengers will not be deterred by overcrowded conditions from using bus services.
An acceptable average peak hour occupancy rate is in the region of 85% to 95%.
Surveys
The peak occupancy rate is best measured by on board stop to stop boarding and alighting surveys. These surveys will provide information on the occupancy at all times and at all locations along the route. This enables the peak load point to be established and the average loading in the peak hour over that section of the route. Since the capacity offered is also known, it is possible to establish the percent occupancy.