The use of raised medians in urban areas has increased in recent years. Raised medians restrict access to businesses along a corridor by limiting turning movements to select mid-block locations. Therefore, a very common remark at public hearings related to the construction of raised medians is that there will be detrimental economic impacts on adjacent businesses. However, the restricted access allows more efficient signalization and traffic flow along the corridor, potentially providing more customers for the businesses.
This report presents recommended improvements for the geometric design and safety performance of at-grade intersections on expressways. In general, the operational and safety performance of these multi-lane divided highways nearly matches those of rural interstates. However, because expressways allow for stop-controlled at-grade crossings, increases in both major and minor roadway traffic volume have had a significant impact on intersection safety in recent years. The study investigated alternate safety improvements and indentified their relative effectiveness and focused on reduci
III. RESEARCH PROBLEM STATEMENT
Access management treatments inherently reduce conflict points along urban arterial roadways. The reduction in conflict has translated to a reduction in crashes that has been documented in numerous studies looking at before and after conditions when access management treatments (i.e., raised median installation, driveway consolidation) are implemented. Crash rate reductions as high as 50 percent have been reported in these analyses.
Federal Highway Administration (FHWA), Safety Benefit of Raised Medians and Pedestrian Refuge Areas, FHWA-SA-10-020, (2010) This document is an excellent summary of the safety benefits of medians for pedestrians, pedestrian access to transit stops, pedestrian crossing maneuvers, as well as benefits of medians in general. It includes several references that will be useful as well. It is of significant value to the AMM2 chapters and sections on impacts of access management techniques and pedestrians. Key findings are reproduced below.