Total population in service area
It is important that the total population in the area served by the bus system is known. This is a key parameter against which others, such as the number of buses operated or the number of passengers carried, can be compared.

In developing countries it is often difficult to obtain an accurate population figure. Often the area served does not coincide with administrative boundaries delineating areas for which population figures are available. In many cities such information is not accurate, particularly those where there are large squatter settlements. Rapid urban population growth also means that population figures are soon out of date.