A system and method for conducting variable VPA testing is disclosed. The method includes provisions to detect or measure the utilization of a trunk line and use that information to establish a level of VPA testing for that trunk line. Although a wide variety of relationships between the utilization and the amount of VPA testing conducted can be used, the relationship is preferably a generally inverse relationship, in which the amount of VPA testing conducted on a particular trunk is reduced as traffic or utilization of the trunk increases. Conversely, as traffic or utilization of the trunk deceases, the amount of testing conducted on the trunk increases.