The challenge associated with measuring performance is complex, often subjective and controversial, and requires careful and prudent forethought. Such is the case in determining the feasibility of making valid comparisons of the performance of state highway systems and evaluation of methodologies used or proposed for use in making such comparisons. This report states the finding and conclusions of a study undertaken to: 1) assess the current practice in comparative program/system evaluation; 2) explore the feasibility of making comparison of the performance of state highway systems; 3) define the characteristics of methodologies used and proposed for use in making such comparison; and 4) propose appropriate actions. An annotated bibliography of pertinent literature is provided in an appendix and is summarised in the report for highway, transportation, and nontransportation cases. Of note were examples of performance measures, system comparisons, and the issues associated with the use or non-use of particular factors. A conceptual framework for program assessment is presented with more focus and description given to three major elements of an assessment methodology: performance measures, input variable, and external factors. The report concludes with a series of observations that provide direction to conducting any comparisons of state highway performance. It is concluded that the performance evaluation of a state's highway program is, and will continue to be, an important component of highway management. However, this review has made it clear that a comparative evaluation of state highway program performance is: 1) an extremely complex activity that must take into account the many external factors that could influence the value of the input or output variables or the relationship between the two; 2) dependent upon the underlying assumption of the cause-effect relationship that is common to all of the programs being evaluated; and 3) dependent upon several characteristics of the data themselves that make consistent and reliable comparative estimates very difficult to do. In summary, no report in the literature was found that provided a sufficiently complete framework and accounting of the above considerations that produced pertinent or constructive comparative evaluation. Following Appendix B in this report is a supplement entitled "Exploring Methodologies for Comparing State Highway Performance" by T.F. Humphrey, M.D. Meyer, and C.M. Walton (pages 31-95). (A)
Samenvatting