A synthesized traffic impact analysis of post-World's Fair site development

Travel demand estimation is necessary to assess the traffic impact of a new development project on its surrounding streets. There are several different techniques currently available for the purpose of estimating future traffic volumes. The most widely used approach is the conventional four-step traffic estimation procedure. But a rigorous application of this comprehensive procedure is time consuming and expensive, and it requires considerable manpower and the use of a large computer. Thus the traditional procedure is not suitable for a quick response to local traffic issues. The objectives of the study were to explore simplified procedures and use a suitable approach in an actual case to quickly generate useful information for resolving a local traffic issue. The case chosen for this purpose involves the traffic impacts of the post-World's Fair site development on the surrounding streets in the Fort Sanders area in Knoxville, Tennessee.

The actual procedure used for this study is a simplified, manual-oriented technique that relies on synthesized trip generation and trip distribution models. Simplification is built on the basic structure of the conventional stepwise process. The primary means used in gathering the data for this study included manual traffic counts, small sample home interviews and business surveys, published materials from studies and reports, and data from local government agencies.

The local traffic issues involved two locations providing access to Fort Sanders area: (1) intersection of Forest Avenue and Summit Hill Drive, and (2) the Clinch Avenue viaduct. The questions raised were whether to close both access points or keep one of them open. Three alternative situations were examined by this study: (1) both locations closed; (2) both locations open; and (3) Forest Avenue and Summit Hill Drive intersection open and Clinch Avenue viaduct closed.

The findings of the study were that it was not desirable to close both access locations and virtually create a peninsula of the Fort Sanders area. The other two options did vary with respect to the generated traffic pattern. In both cases the traffic on the existing streets in the Fort Sanders area can be handled with improvements of certain key intersections. The quantifiable project costs for the two alternative options of reopening or closing permanently the Clinch Avenue viaduct did not differ significantly. The major differences of the two options lie in nonquantifiable factors including environmental impacts. As such the final decision on which option to adopt must be made by the decision maker, based on given objectives and his judgment.

The study demonstrated that the simplified technique can be used to estimate the future traffic volumes quickly and at a low cost. Consequently, this approach would enable policymakers to seek technical assistance from planners and traffic engineers and use factual information in decision making.