Transportation planning at both the state and metropolitan planning organization (MPO) levels requires that the impact of transportation investment decisions on land-use patterns be considered. This implies that every action, from adding capacity to managing access, has some interrelationship with land-use and land development patterns. Much of this implied interrelationship is anecdotal, or, at best, empirical, because there is little available factual and quantifiable information on impacts. Nevertheless, it is clear that transportation policies and their relationship to land-use planning have significantly changed and are continuing to evolve in the post-Interstate era. There is a very critical need to provide land-use impact information and analysis tools to help decision makers meet the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991 planning requirements. Decision makers must be able to certify that land-use impacts have been considered in their transportation plans.

ISTEA calls for joint decision making on a metropolitan level in conducting transportation and land-use planning. MPOs and state departments of transportation (DOTs) are required to consider land-use alternatives to transportation solutions such as those required by management systems and major investment studies.

The success of transportation capacity improvements, travel demand reduction measures, and the use of alternative modes all depends in part on the land use. Rural, suburban, and urban land-use patterns including issues such as renewal, sprawl, environmental concerns, and economic growth are all affected by transportation strategies. Better coordination of regional transportation planning with local land-use planning can help to optimize the timing of investments, help to identify transportation facilities and services needed to serve or modify land uses, and help to coordinate the nature and pattern of land development with available transportation modes. As a result, it is essential that these coordination activities be supported by an accurate, consensus-based analytical process. Research is needed to develop analytical tools for use by transportation and land-use planners and decision makers at federal, state, MPO, and local levels of government.

The objective of this research is to provide planners and decision makers with effective analytical tools that describe and measure the interrelationships between transportation facilities and services and land-use on a regional and project-level basis. More specifically, this research will accomplish the following: (1) define appropriate methods and procedures for quantifying transportation and land-use effects; (2) describe how transportation investments (such as, transit and highways) and strategies (for example, Transportation Control Measures and Transportation Demand Management) influence land use; (3) identify the sensitivity of different land-use patterns to transportation; and (4) develop analytical tools to enable transportation planners and land-use planners to jointly implement transportation and land development goals.

To accomplish these objectives, the following tasks will be performed: (1) Conduct a critical literature review that will describe the interrelationships between transportation investments and strategies and land-use decisions. Conduct a state-of-the-practice review and evaluation of available analytical tools for measuring transportation and land-use interrelationships. (The contractor shall include an international perspective as part of this task.) (2) Identify the interrelationships of land-use intensity and mix with various transportation investments and strategies, both short and long term. Define appropriate methods and procedures for quantifying transportation and land-use effects. Develop a common measurement format to quantify these interrelationships. The contractor will look beyond existing measurement formats for this task. The contractor will submit an interim report within 6 months for NCHRP review. This report will include the results of Tasks 1 and 2 and a revised work plan for Tasks 3, 4, and 5. The panel will meet with the contractor to discuss the interim report and approve the remaining work on this project. (3) Develop analytical tools for use by planning professionals for analysis of transportation investments and strategies and land development goals. (4) Develop a guidance document for federal, state, regional, and local planners and decision makers that identifies the interrelationships between land-use patterns and transportation investment strategies. This document shall also contain analytical tools that can be used to quantify the impacts of the interrelationships. The guidance and tools contained in this document should be usable in the planning process in response to the ISTEA requirements. (5) Develop recommendations and cost estimates for case studies and data that will be needed to test the analytical tools identified. These recommendations will address impacts of transportation on land use and impacts of land use on transportation. These recommendations will also serve as the work plan for an anticipated second phase of this research effort to be done under a separate contract. (6) Prepare a final report on the findings of the research. The report shall also contain recommendations for further research.

Status: The project has been completed. A summary NCHRP research results digest will be prepared to refer to a contractor-maintained website for the latest version of the UrbanSim Land Use Model.

Product Availability: The final report has been published as NCHRP Report 423A, "Land Use Impacts of Transportation: A Guidebook." The UrbanSim model and the latest information regarding its development can be obtained through the website (www.urbansim.org).