Guidelines for traffic impact analysis of developments along state highways

With intensification of urban development and dwindling public resources, assessing the impacts of a new development (called impact analysis) is becoming an important planning tool for transportation engineers. The traffic impacts of new developments can be foreseen and effective mitigating measures can be planned using optimal allocation of the available funds. This study establishes a detailed and standardized methodology for traffic impact analysis along highways under the jurisdiction of the Indiana Department of Transportation. The manual produced by this study can be used by other transportation agencies as well with little or no modification. A new methodology for estimating the percentage of pass-by trips using a license plate survey (instead of the traditional interview survey) is presented. The report also demonstrates how Bayesian statistics can be used to update the national ITE Trip Generation data base with limited local data to derive more reliable local trip generation rates. A status report on traffic impact analysis and impact fees in various state transportation agencies has also been included. A brief discussion of impact fee structure has been incorporated.