Start date: 07/23/08
End date: 10/29/08
About the research
In April 2008 a preliminary investigation of fatal and major injury crashes on Iowa’s primary road system from 2001 through 2007 was conducted by the Iowa Department of Transportation, Office of Traffic and Safety. A mapping of these data revealed an apparent concentration of these serious crashes on a section of Iowa 25 north of Creston. Based on this information, a road safety audit of this roadway section was requested by the Office of Traffic and Safety.
Iowa 25 is a two-lane asphaltic concrete pavement roadway, 22 ft in width with approximately 6 ft wide granular shoulders. Originally constructed in 1939, the roadway was last rehabilitated in 1996 with a 4-in. asphalt overlay. Except for shoulder paving through a curve area, no additional work beyond routine maintenance has been accomplished in the section. The 2004 traffic map indicates that IA 25 has a traffic volume of approximately 2070 vehicles per day with 160 commercial vehicles. The posted speed is 55 mph.
This report contains a discussion of audit team findings, crash and roadway data, and recommendations for possible mitigation of safety concerns for this roadway section.
Report: Road Safety Audit for Union County IA 25 from the WCL of Creston to North H-24 Intersection (2.59 mb pdf) July 2008
Sponsor(s): Iowa Department of Transportation