FIGURE 4-1 General framework of performance measures.

bilities for infrastructure management explicitly define a comprehensive set of performance measures. The measures selected should reflect the concerns of stakeholders about the important consequences of infrastructure systems and recognize interrelationships across infrastructure modes and jurisdictions. The committee's framework—in particular, effectiveness, reliability, and cost as the principal dimensions of performance—is a useful basis for defining these measures. There are many sources of example measures on which agencies can draw. At the national level, President Clinton's "Reinventing Government" initiative has generated extensive discussion of how management performance of government agencies can be measured and improved. The Intermodal Surface Transportation Efficiency Act of 1991 has spawned studies in the state departments of transportation to develop measures of intermodal performance.¹ The APWA has issued a report that offers many rules of thumb for assessing local agency management practices. ² The committee reviewed examples of such work and found them useful but generally less comprehensive and detailed than the framework the committee had in mind.

There are fewer sources of information on the functional interactions across infrastructure modes. Urban planners, for example, have sought to devise mathematical models that can forecast the influence of infrastructure investment on patterns of land use in a metropolitan area. Economists similarly have attempted to assess the influence of total infrastructure