Results from Implementation of Integrated Transportation and Land Use Models in Metropolitan Regions

The general notion that operating agencies should attempt to integrate transportation and land use planning has long been espoused by both practicing planners and scholars. Some of the earliest work on the methodological aspects of this goal, as related to computer modeling of the processes, was sponsored by the U.S. Federal Highway Administration in an attempt to resolve what they then labeled as “the problem of premature obsolescence of highway facilities”. The earliest successful attempt to develop a modeling approach to these issues demonstrated that there were important interactions which most traditional planning methods overlooked (Putman, 1973). At the same time, this early study was unable to resolve important conceptual and computational problems of how to fully implement such integrated, or combined, model approaches. Part of the problem had to do with then available theory, and part with then available computer technology. The general problem had been formulated earlier (Beckmann et al., 1956), but the relevance of that work was not known to the transportation and land use modeling community. In 1973 the cost, at academic computing rates, of just one trip assignment model run was in excess of $200 (US), and most computer runs had to be submitted for overnight processing.