Systemic Safety Project Selection Tool

FIGURE 11. Illinois Department of Transportation Illustration of Cable Median Barrier Program Results for Treated Locations – Long Description

Figure 11 is a graph displaying the relationship between the number of Cross-Median Crashes and the number of miles of Cable Median Barriers. The horizontal axis unit is the year, ranging from 2001 to 2008. There are two vertical axes: Cross-Median Crashes with an axis range from zero to 18, and Cable Median Barrier Installed (miles), ranging from zero to 270. The Total cross-median crashes are presented alongside fatal cross-median crashes.

From 2001 through 2004 there were zero miles of cable median barrier installed. In 2001 there were 10 cross-median crashes, three of which were fatal. In 2002 there were six cross-median crashes, two of which were fatal. In 2003, there were 11 cross-median crashes, none of which were fatal. In 2004, there were 13 cross-median crashes, eight of which were fatal.

In 2004, the Department of Transportation started installing cable median barrier. In 2005, a peak of 16 cross-median crashes occurred, five of which were fatal. In 2005 there were 32 miles of cable median barrier installed, increasing to 108 in 2006, 185 in 2007, and 210 in 2008, demonstrating a steady increase across this time period. In both 2006 and 2007, there were four cross-median crashes with two fatalities. In 2008, there were zero cross-median crashes.

The graph suggests an inverse relationship between the number of cross-median crashes and number of miles of cable median barriers.