Issaquah Highlands is a unique, fast track development that is currently under construction in Issaquah, Washington, a suburban community in the Seattle region. A traffic study was prepared to analyze and refine the proposed roadway plan for the Town Center area of the development. While the preparation of a traffic study can be a fairly routine task, the project history, the development size, the project pace, the variable land uses, and the developer's need to maintain land use flexibility added to the project's complexity. The proposed mixed land use development includes over 3.5 million square feet (sf) of retail and office space, as well as a 1,000-stall park-and-ride and over 3,000 homes. The project area includes 14 town blocks and 12 major intersections forming a one-way couplet. Two key factors or "tools" led to the success of this project and will be discussed in this paper: the project team's communication and inclusive process, and, the combined use, flexibility and application of various traffic software packages. Project stakeholders for this study included four agencies, two non-transportation developer/owner representatives, and independent traffic engineers representing two Cities and one owner. Coordination and communication among all these stakeholders and decision makers was vital to the project's success. In order to fully study and evaluate the options that were brought forward during this project, a variety of planning, macroscopic simulation and microscopic simulation tools were used in combination. The integration of four software packages allowed some flexibility and time savings, and also provided a variety of data analysis and presentation methods. The combined process of clear communication and software integration helped ultimately gain City Council approval of the project, and provided some lessons for use on future projects of any scale.
Abstract