4500 South (300 West to State Street) closure: the evaluation of users' impacts

Utah Department of Transportation (UDOT) identified the part of 4500 South (from 300 West to State Street) in Murray City, Utah as a bottleneck. UDOT decided to add an additional lane in each direction (on previously a two-lane section). Three possible alternatives on how this work should be done were developed: (1) complete closure for 8 weeks, (2) closure during the night for 6 months, and (3) closing one direction at a time for 6 weeks in each direction. The goal of this study was to examine the impact of the alternative construction methods for these alternatives on road user delay and emission using macro-simulation. After the geometry of the model was improved and the model was calibrated, three alternatives (besides no-build and after-implementation) were developed and tested. Observed measures of effectiveness were costs of users' delays, levels of emission (Carbon Monoxide, Nitrogen Oxide, and Volatile Oxygen Compounds) and volume/capacity ratio. Results showed that working during nights (and leaving lanes open during the day) would have had the lowest impact on users in terms of delays. This study also concluded that emissions are insensitive to this kind of work. Volume/capacity ratio showed considerable lane efficiency improvement.