Documentation was done on the effect of a raised median, signalized and redesigned intersections, curbs, and sidewalks on vehicle speed, pedestrian exposure risk, driver predictability, and vehicle volume along a four-lane suburban roadway in central New Jersey. The analysis used both quantitative tools (speed and volume counts, timing runs) and qualitative methods (pedestrian tracking, video, before-and-after photography). The results are that the 85th-percentile vehicle speed fell by 2 mi/h and pedestrian exposure risk decreased by 28%. Also, the median allows pedestrians to cross one direction of traffic at a time and signals, curbs, median, redesigned intersections, and striping patterns work together to manage driver behavior. In regard to vehicles, it was found that vehicle volumes were not affected and that vehicle speeds acted independently of vehicle volumes. A collision analysis projected a savings of $1.7 million over the next 3 years in direct and indirect costs. The goal of the report was to produce a simple and straightforward analysis tool for similar projects in the area. Some of the benefits of roadway projects such as these can be quantified numerically, whereas others rely on qualitative analyses. For example, before-and-after speeds are easily gathered and compared, whereas before-and-after pedestrian behavior at the raised median requires a more in-depth approach made easier by digital cameras. Together, before-and-after data and before-and-after imaging present a more holistic picture of the benefits and limitations of a project.
Abstract