, Former Research Associate Professor, Civil, Environmental and Geo-Engineering
Gary Davis, Professor, Civil, Environmental and Geo-Engineering
Transportation professionals are sensitive to public dissatisfaction with work- zone congestion, delay, and safety, and continually develop new approaches to improve traffic operations in and around work zones. Transportation agencies must take into account both the need for work zones and mobility and safety concerns expressed by the public and government agencies. Full-road closure is one method that is increasingly being considered during project planning and design as a potential way to balance conflicting needs.This study analyzed the effects and measured the benefits of full-closure construction. It had the unique advantage of using an actual ongoing project as a test case; Metro District selected the full closure of Trunk Highway (T.H.) 36 to construct a project in North St. Paul. Researchers evaluated traffic operations and extracted performance measures from the four basic alternatives: no-build, build, non-full-closure construction, and full-road closure construction. This provided valuable data for the cost/benefit analysis, as well as effective traffic management on future full-road closure projects. The study culminated in the creation of a guide for engineers considering full road closure as a construction alternative in future projects. Evaluating the T.H.-36 full-road closure was accomplished two ways: 1) detector and other measurements were retrieved and analyzed for the time periods before, during, and after the full-road closure, and 2) a comprehensive microscopic model of the area of influence of the T.H.-36 construction project was built and used to quantify the traffic operations performance during the full-road closure, as well as the alternative partial closure. Field measurements showed a larger-than-anticipated area of influence for the full closure and suggested that road users did not always follow prescribed alternative routes serving the area. In addition, a number of local streets around the project area showed higher than expected traffic patterns, but without leading to major congestion problems.