Communities want large tourist attractions that bring millions of visitors and dollars to their economy. Once the opportunity presents itself, how does a community, particularly a small one, measure the demands placed on the infrastructure with very little details about the proposed developments? A commitment must often be made before the necessary details are worked out. It is possible to measure likely impacts using speculative information as long as all parties understand the opportunities and limitations of the information and understand and agree with the assumptions and processes used in identifying the impacts. The City of Coralville, IA has been selected as the future sight of a large environmental learning center that will bring an estimated 1.5 million annual visitors to the area. The city is also developing an additional 1.5 million square feet of commercial, retail, and residential land use in the proposed area along with a large hotel and conference center. All of this development is planned for a 146 acre redevelopment parcel with only one roadway providing access. A traffic study was initiated to measure the impacts of the individual uses, and then organize them into logical development patterns. The scenarios where used to identify the roadway improvements required at various stages and whether the existing system could accommodate the "full-build" without major improvements. The study faced a challenge of being as accurate as possible while using only projected traffic and land use information for the proposed developments. The charge was also placed to identify opportunities for alternative modes and remote parking scenarios. Methods and assumptions were established at the beginning to prevent the project from getting mired in issues that were not relative to the project and to prevent the study from being completed around the answer. The study looked at the large attraction and the proposed surrounding uses and identified by parcel the amount, types, and time of day characteristics of traffic to measure the peak hour demand on the corridor intersections and what the impacts will be. The result was a summary of scenarios and a timeline for the needed improvements to be used in the decision process.
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