In one aspect thereof the exemplary embodiments provide a data processing system that includes at least one data processor; at least one memory connected with the data processor and that stores computer software that is executable by the at least one data processor; at least one database storing a plurality of fares and rules establishing conditions under which at least one of the fares can be applied; and an interface to at least one user and configured to receive from the user a fare inquiry. The data processor is configured with the computer software to cause the data processing system to receive a fare inquiry that contains at least one rule attribute, to perform a first search to determine rule data applicable to the at least one rule attribute, and to perform a second search using the rule data to retrieve a list of fares that are applicable to the rule data.