Sampling design for local public transport assessment

The diffusion of the so-called Assessment Transportation has led local public transport companies to apply assessment procedures of Passengers Satisfaction. These procedures require statistical sampling surveys of the customers of the public transport from which to extract information useful for the management. A crucial step in defining the sampling design is the choice of how to select the units which, in the context of transport, are clustered and sparsely distributed over the study area. In these circumstances, standard sampling techniques cannot be applied and the authors propose the use of a specific sampling design called Intersect Units Sampling often used for monitoring biological populations. This technique selects the units along a transport service-line following a specific sampling design. The design proposed is easy to apply and leads to efficient estimators.