Problems encountered in the first seven years of operation of the Interlibrary Delivery System (IDS) for the transport of interlibrary loan materials among libraries in Pennsylvania prompted this study of present delivery at the local and state levels, with the objectives of evaluating benefits, costs, routing, funding, and governance of delivery systems. This report describes the development of IDS, evaluates its current operations and costs in comparison with those of the U.S. Postal Service and other commercial carriers, and evaluates the feasible alternatives to IDS. The major recommendations are that IDS should be retained with much of its present structure, but that an annual appropriation should be sought from the state legislature to subsidize the service in lieu of LSCA funds, giving it the stability in funding which it needs for sound planning and development. Data collected through on-site visits, interviews, and questionnaires are presented in 27 tables, and maps showing the various systems, delivery areas, and routes are provided. (Author/JVP)