Improving the Design and Operation of Highway Intersections

Although intersections only constitute a small percentage of the overall roadway system in Delaware, intersections are one of the most complex traffic situations that motorists encounter and should be considered a priority area in addressing fatal crashes in the state and nationwide. Both signalized and unsignalized intersections involve multiple turning and crossing maneuvers that create numerous conflict points and crash potentials between vehicles, pedestrians and bicyclists. Intersection fatalities have been increasing in Delaware in recent years; therefore the 2010 Delaware SHSP includes intersection safety as an emphasis area to reduce overall fatal crashes. Although improving intersection safety was not included as an emphasis area in previous versions of the Delaware SHSP, DelDOT has several established safety programs in place to identify safety and operational improvements at high crash locations, many of which include intersections

Improvement Program - Dark Criteria Studies

Thirty-three (33) percent of fatal intersection crashes occurred under dark/unlit conditions from 2007 through 2009 according to the Delaware SHSP. DelDOT, using its Crash Analysis Reporting System, recently began a program to rank high crash locations based on specific crash types or crash circumstances. Crash types include roadway departure or intersection crashes. Crash circumstances include crashes occurring under dark/unlit conditions or crashes occurring on wet pavement conditions. Through the review of more specific crash data, DelDOT developed a ranking of high crash locations involve crashes under dark/unlit conditions (dark criteria). The top ten locations from the initial rankings were selected for study to determine the need for safety improvements to address not only dark/unlit condition crashes, but total crashes overall. The ten locations studied and the resultant evaluation reports and improvement recommendations are provided in the table below. Moving forward, evaluations of high crash locations based on dark/unlit crash conditions will be undertaken every five years. The goal of this program is to identify those intersections or corridors that would benefit the most from intersection or roadway lighting or other safety countermeasures that can reduce the frequency of dark/unlit condition crashes. Besides intersection or roadway lighting, improvements could include the installation of recessed pavement markings, upgrade of existing pavement markings, tree trimming to improve intersection visibility and enhanced signage approaching intersections.