Road Safety Audit for Union County IA 25 from the WCL of Creston to North H-24 Intersection, 2008

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.

Road Safety Audit for US 6 from the ECL of Iowa City to the WCL of West Liberty in Johnson and Muscatine Counties, Iowa, 2008

Approximately 13.2 miles of US 6 in eastern Iowa extends from the east corporate limits of Iowa City, Iowa, to the west corporate limits of West Liberty, Iowa. This segment of US 6 is a service level B primary highway, with an annual daily traffic volume varying from 3,480 vehicles per day (vpd) to 5,700 vpd. According to 2001–2007 crash density data from the Iowa Department of Transportation (Iowa DOT), the corridor is currently listed among the top 5% of non-freeway Iowa DOT roads in several crash categories, including crashes involving excessive speed, impaired drivers, single-vehicle run-off-road, and multiple-vehicle crossed centerline. A road safety audit of this corridor was deemed appropriate by the Iowa Department of Transportation’s Office of Traffic and Safety. Staff and officials from the Iowa DOT, Iowa State Patrol, Governor’s Traffic Safety Bureau, Federal Highway Administration, Center for Transportation Research and Education, and several local law enforcement and transportation agencies met to review crash data and discuss potential safety improvements to this segment of US 6. This report outlines the findings and recommendations of the road safety audit team to address the safety concerns on this US 6 corridor and explains several selected mitigation strategies.

Road Safety Audit Report for US 61 from the ECL of Muscatine to the WCL of, 2008

U.S. Highway 61 between Muscatine and Davenport, Iowa, is a four-lane divided section of road approximately 21 miles in length. This section was found to be among the top 5% of Iowa roadways for single-vehicle run-off-road, impaired driver, unbelted driver, and speed-related crashes for the period of 2001 through 2005. A road safety audit of this corridor was deemed appropriate by the Iowa Department of Transportation’s Office of Traffic and Safety. Staff and officials from the Iowa Department of Transportation (Iowa DOT), Iowa State Patrol, Governor’s Traffic Safety Bureau, Federal Highway Administration, Center for Transportation Research and Education, and several local law enforcement and transportation agencies met to review crash data and discuss potential safety improvements to US 61. This report outlines the findings and recommendations of the road safety audit team to address the safety concerns on this US 61 corridor and explains several selected mitigation strategies.

Road Safety Audit for the US 61/Harrison Street and West Locust Street Intersection in Davenport-Scott County, Iowa, 2008

On the October 7 and 8, 2008, a road safety audit was conducted for the intersection of US 61/Harrison Street and West Locust Street in Davenport, Iowa. US 61/Harrison Street is a one-way street and a principal arterial route through Davenport, with three southbound lanes. Locust Street is a four-lane, two-way minor arterial running across the city from west to east. The last major improvement at this intersection was implemented approximately 20 years ago. The Iowa Department of Transportation requested a safety audit of this intersection in response to a high incidence of crashes at the location over the past several years, in view of the fact that no major improvements are anticipated for this intersection in the immediate future. The road safety audit team discussed current conditions at the intersection and reviewed the last seven years of crash data. The team also made daytime and nighttime field visits to the intersection to examine field conditions and observe traffic flow and crossing guard operations with younger pedestrians. After discussing key issues, the road safety audit team drew conclusions and suggested possible enforcement, engineering, public information, and educational strategies for mitigation.

Road Safety Audit for County Road X-37, from the Intersection of G-62 to the East Corporate Limits of Columbus City in Louisa County, Iowa, 2009

A road safety audit was conducted for a 7.75 mile section of County Road X-37 in Louisa County, Iowa. In 2006, the average annual daily traffic on this roadway was found to be 680 vehicles per day. Using crash data from 2001 to 2007, the Iowa Department of Transportation (Iowa DOT) has identified this roadway as being in the highest 5% of local rural roads in Iowa for single-vehicle runoff- road crashes. Considering these safety data, the Louisa County Engineer requested that a road safety audit be conducted to identify areas of safety concerns and recommend low-cost mitigation to address those concerns. Staff and officials from the Iowa DOT, Governor’s Traffic Safety Bureau, Federal Highway Administration, Institute for Transportation, and local law enforcement and transportation agencies met to review crash data and discuss potential safety improvements to this segment of X-37. This report outlines the findings and recommendations of the road safety audit team to address the safety concerns on this X-37 corridor and explain several selected mitigation strategies.

Road Safety Audit for County Road W-55 in Washington County, Iowa, 2009

A road safety audit was conducted for a seven-mile section of County Road W-55 in Washington County, Iowa. In 2006, the average annual daily traffic on this roadway was found to be 1,290 vehicles per day. Using crash data from 2001 to 2007, the Iowa Department of Transportation (Iowa DOT) has identified this roadway as being in the top 5% of Iowa secondary rural roads with the highest density of serious (fatal and major injury) crashes for single-vehicle run-off-road incidents. Considering these safety data, the Washington County Engineer requested that a road safety audit be conducted to identify areas with safety concerns and to recommend low-cost mitigation to address those concerns. Staff and officials from the Iowa DOT, Iowa State Patrol, Governor’s Traffic Safety Bureau, Federal Highway Administration, Institute for Transportation, and local law enforcement and transportation agencies met to review crash data and discuss potential safety improvements to this segment of W-55. This report outlines the findings and recommendations of the road safety audit team to address the safety concerns on this W-55 corridor and explain several selected mitigation strategies.

Road Safety Audit for Intersection of US 218 and County Road C-57 (West Cedar Wapsi Road) in Black Hawk County, Iowa, 2009

Beginning on June 22, 2009, a road safety audit was initiated for the intersection of US 218 and County Road C-57 in Black Hawk County, Iowa. Due to the traffic volumes and the number of conflicting traffic movements on these two roadways, this intersection has developed a crash history that concerns the Iowa Department of Transportation (Iowa DOT), Iowa State Patrol, and local agencies. This intersection is ranked seventh in Iowa for the highest number of at-grade expressway intersection crashes. Considering this, Black Hawk County and the Iowa DOT requested that a road safety audit be conducted to address the safety concerns and recommend possible mitigation strategies.

Road Safety Audit for Intersection of IA 1 and County Road R-67 in Johnson County, Iowa, 2009

On August 3, 2009, a road safety audit was initiated for the intersection of IA 1 and County Road F-67 in Johnson County, Iowa. Due to the high volume of traffic accessing the cheese producing plant (Twin County Dairy, Inc.), a grocery store east of the intersection, and a large Amish community with horse-drawn wagons and carriages frequently sharing the roads with motorized vehicles, this intersection has developed a crash history that concerns the Iowa Department of Transportation (Iowa DOT), Iowa State Patrol, and local agencies. Considering this, Johnson County and the Iowa DOT requested that a road safety audit be conducted to address the safety concerns and recommend possible mitigation strategies.

Road Safety Audit for IA 150/US 52 from I-380 to the Minnesota Border, 2009

On June 9, 2009, the Northeast Iowa Highway 150/52 Coalition met with the Iowa Department of Transportation (Iowa DOT) in Cedar Falls, Iowa to discuss concerns regarding roadway conditions and safety which has become a concern because of the potential economic development in the area. In response to the issues raised by the coalition, the Iowa DOT requested that a road safety audit be conducted on the corridor to identify where low-cost improvements could be beneficially applied to address safety concerns.

Road Safety Audit for I-380 through the Cities of Cedar Rapids and Hiawatha in Linn County, Iowa, 2009

Interstate 380 (I-380) through Cedar Rapids and Hiawatha, Iowa, is a multilane divided urban freeway that was constructed in 1976 to the Cedar River and in 1981 from that point northerly. Traffic volumes vary from 47,000 to 83,500 vehicles per day, with about 8%–15% trucks and buses. Based on concern for the high number of crash incidents, particularly serious crashes, and increased traffic volumes on this roadway, the City of Cedar Rapids and the Iowa Department of Transportation (Iowa DOT) District 6 Office requested that a road safety audit be conducted for this roadway section. Representatives from the Iowa DOT, Federal Highway Administration, Center for Transportation Research and Education, local law enforcement, local government, and area businesses met to review crash data and discuss potential safety improvements to this segment of I-380. This report outlines the findings and recommendations of the road safety audit team for addressing the safety concerns on this I-380 corridor and explains several selected mitigation strategies.

Spatial Scale of Clustering of Motor Vehicle Crash Types and Appropriate Countermeasures, 2009

This project analyzes the characteristics and spatial distributions of motor vehicle crash types in order to evaluate the degree and scale of their spatial clustering. Crashes occur as the result of a variety of vehicle, roadway, and human factors and thus vary in their clustering behavior. Clustering can occur at a variety of scales, from the intersection level, to the corridor level, to the area level. Conversely, other crash types are less linked to geographic factors and are more spatially “random.” The degree and scale of clustering have implications for the use of strategies to promote transportation safety. In this project, Iowa's crash database, geographic information systems, and recent advances in spatial statistics methodologies and software tools were used to analyze the degree and spatial scale of clustering for several crash types within the counties of the Iowa Northland Regional Council of Governments. A statistical measure called the K function was used to analyze the clustering behavior of crashes. Several methodological issues, related to the application of this spatial statistical technique in the context of motor vehicle crashes on a road network, were identified and addressed. These methods facilitated the identification of crash clusters at appropriate scales of analysis for each crash type. This clustering information is useful for improving transportation safety through focused countermeasures directly linked to crash causes and the spatial extent of identified problem locations, as well as through the identification of less location-based crash types better suited to non-spatial countermeasures. The results of the K function analysis point to the usefulness of the procedure in identifying the degree and scale at which crashes cluster, or do not cluster, relative to each other. Moreover, for many individual crash types, different patterns and processes and potentially different countermeasures appeared at different scales of analysis. This finding highlights the importance of scale considerations in problem identification and countermeasure formulation.

Road Safety Audit for County Road H-46 from Redwood Avenue to the Southerly Corporate Limits of Fairfield in Jefferson County, Iowa, 2010

Jefferson County Road H-46 from Redwood Avenue to the southeast corporate limits (SCL) of Fairfield, Iowa, is a paved roadway approximately 6.5 miles long made of asphaltic concrete pavement with curvilinear alignment. The roadway consists of a 22 ft wide pavement, last overlaid in 2002, with 3 to 4 ft wide earth shoulders. Traffic estimates indicated volumes ranging from 500 to 1,590 vehicles per day, with numbers increasing as the route nears Fairfield. This roadway was found to be among the highest 5 percent of similar Iowa roadways in terms of severity of run-off-road crashes. In response, Iowa Department of Transportation (Iowa DOT) requested a road safety audit to examine the roadway and suggest possible mitigation. Representatives from the Iowa DOT, Federal Highway Administration, Institute for Transportation, local law enforcement, and local government met to review crash data and discuss potential safety improvements to this segment H-46. This report outlines the findings and recommendations of the road safety audit team for addressing the safety concerns on this roadway.

Road Safety Audits for County Road X-23 from IA 2 to the South Corporate Limits of West Point and for County Road W-62 from US 218 to IA 27 in Lee County, Iowa, 2010

On October 20–21, 2009, two road safety audits were conducted in Lee County, Iowa: one for a 6 mile section of County Road X-23 from IA 2 to the south corporate limits of West Point and one for a 9.7 mile section of County Road W-62 from US 218 to IA 27. Both roads have high severe crash histories for the years of 2001 through 2008. Using these crash data, the Iowa Department of Transportation (Iowa DOT) has identified County Road X-23 as being in the top 5 percent of similar roads for run-off-road crashes. The Iowa DOT lists County Road W-62 as a high-risk rural road that has above-average crash numbers and is eligible for funding under the Federal High-Risk Rural Road Program. Considering these issues, the Lee County Engineer and Iowa DOT requested that road safety audits be conducted to address the safety concerns and to suggest possible mitigation strategies.

Road Safety Audit for US 151 from Amana to US 30 in Cedar Rapids in Benton, Iowa and Linn Counties, Iowa, 2010

US 151 was originally constructed as IA 149 in 1931-1934 and has been rehabilitated several times. The most recent major improvements, which were completed in 2005-2006, consisted of hot mix asphalt resurfacing and partial shoulder paving. Major widening and resurfacing improvements were also completed in 2007 between Fairfax and US 30 in Cedar Rapids. According to a preliminary 2009 estimate, traffic volumes range from about 5,900 vehicles per day (vpd) north of Amana to about 14,400 vpd at the US 30 interchange in Cedar Rapids. In response to high crash densities and medium to medium-high crash rates along the route, the Iowa Department of Transportation (Iowa DOT) requested a road safety audit to examine the roadway and suggest possible mitigation. Representatives from the Iowa DOT, Federal Highway Administration, Institute for Transportation, local law enforcement, and state government met to review crash data and discuss potential safety improvements to this segment of US 151. This report outlines the findings and recommendations of the road safety audit team for addressing the safety concerns on this roadway.

Road Safety Audit for James Avenue NW and 250th Street NW, from the North Corporate Limits of Tiffin to I-380, in Johnson County, Iowa, 2010

To address safety concerns on James Avenue NW and 250th Street NW, from the North Corporate Limits (NCL) of Tiffin, north and east to I-380 (at North Liberty), the Johnson County engineer requested a road safety audit (RSA). The audit was conducted on September 1, 2010, through a program supported by the Office of Traffic and Safety at the Iowa Department of Transportation (DOT). This road is a seal-coated roadway, about 25-ft wide, but with only about 0-1 ft of earth shoulders. According to 2006 Iowa DOT estimates, traffic volume is about 820 vehicles per day, north from Tiffin to a commercial entrance on 250th Street, then increasing to 2,990 vehicles per day to the on-ramp of Interstate 380 (I-380). Local traffic uses this road as a short-cut to Cedar Rapids, North Liberty, and the I-380/I-80 interchange (to avoid congestion on IA 965). This report outlines the findings and recommendations of the road safety audit team for addressing the safety concerns on this roadway.