Data-Driven 

Safety Analysis 

PROJECT CASE STUDY 

Minnesota’s Systemic Approach Integrates Safety Performance 

into Investment Decisions for Local Roads 

Historically, approximately 60 percent of severe (fatal and serious injury) crashes have occurred on Minnesota’s 

local road system. As the crashes occurred throughout many miles of roadways, the low crash density had 

resulted in the roads receiving minimal safety investment based on the traditional site analysis approach. To 

address this issue, the Minnesota Department of Transportation (MnDOT) assisted the counties in identifying lowcost, safety-related projects to implement on a systematic basis. The result has been far fewer fatalities on the 

county roadways. 

Project Description 

MnDOT’s approach involved developing Road Safety Plans (RSPs) for each of the state’s 87 counties, building 

on Minnesota’s Strategic Highway Safety Plan (SHSP), to identify specific safety projects that would directly 

address the factors associated with the most severe crashes on each county’s highway system. 

To develop the safety plans, MnDOT conducted a statewide, comprehensive crash analysis as documented 

in the Federal Highway Administration (FHWA) Systemic Safety 

Project Selection Tool. This helped the counties identify the SYSTEMIC SAFETY

ANALYSIS BENEFITS

Improved Safety

Systemic safety analysis helps identify

priority crash types that represent the 

greatest potential for crash reduction. 

Informed Decision-Making 

Agencies can address high-risk elements 

not typically identified through traditional 

approaches. 

Optimized Investment

Allows consideration of risk along with

crash history for a comprehensive 

approach to deploying low-cost 

countermeasures. 

proportion of crashes occurring in urban versus rural areas, 

whether they were on state or local roads, their severity, and the 

primary crash types. The analysis showed that there were more 

severe crashes on the county system than on the state system 

and that the majority of these crashes were rural, involved 

roadway departure, and occurred on curves more than 50 

percent of the time. 

They disaggregated the statewide crash data based on the 

emphasis areas designated in the American Association of 

State Highway and Transportation Officials (AASHTO) Strategic 

Highway Safety Plan. The areas identified represented the best 

opportunities for a significant reduction in the number of severe 

and fatal crashes for each county. 

MnDOT compiled an initial list of the safety countermeasures 

that had the greatest potential to address the focus crash types. 

Focus Area Risk Factors 

` Curves ` traffic volume, curve radius, presence of a visual trap, presence of an intersection, severe

crash history

` Intersections ` geometry, traffic volume, proximity to a railroad crossing, commercial development

` Segments ` traffic volume, density of roadway departure crashes, curve density, edge risk assessment,

access density
They screened the countermeasures using crash data, 

effectiveness and cost along with agency policies, 

procedures and experience. The result was a short list of 

safety strategies for each focus crash type. 

MnDOT also performed a detailed crash analysis to 

identify contributing crash factors and characteristics 

based on the findings of the initial crash analysis. This 

Key Takeaway 

` Systemic analysis includes all stakeholders and

can be accomplished through partnerships 

with local agencies. 

detailed analysis identified the high-risk locations on the 

two-lane, rural county highways (including segments, intersections and curves) based on system-wide factors 

such as the number of severe crashes, design features, traffic volumes and curve radius. 

For example, two-lane rural curves were selected as one focus crash type. In analyzing the county roadways 

and applying the risk factors for curves, MnDOT found that severe crashes were overrepresented on roadways 

with 500-1,500 in average daily traffic volume. Similarly, when comparing the percentage of both fatal and 

severe roadway departure crashes occurring on a specified curve radius, MnDOT identified curves with a 

500-1,500 foot radii as possible targets for systemic improvements. They also reviewed these locations for the 

presence of visual traps or intersections. In all, MnDOT analyzed 504 curves as part of this systemic analysis, 

resulting in the identification of 32 high-priority curves. 

The priority safety strategies eventually selected for the three focus areas included enhanced road edges 

with rumble strips and 6-inch edge lines, enhanced curve delineation (chevrons), and upgraded traffic signs 

and streetlights for intersections. MnDOT added this systemic component to its Highway Safety Improvement 

Program (HSIP) in order to fund the projects that the RSP program helped the counties identify. 

Conclusions 

MnDOT’s systemic analysis used a data-driven, systematic process to develop specific safety projects for each 

site targeted for investment. It provided a decision-making process for countermeasure selection that allowed 

county engineers the opportunity to identify treatment preferences while selecting projects for MnDOT funding. 

In addition, developing the RSPs increased general awareness and familiarity among the local agencies in 

identifying safety issues on their roadways and suitable countermeasures to address them. 

ADDITIONAL RESOURCES 

` Additional details on this project and on FHWA’s Systemic Safety Project Selection Tool are available at: 

http://safety.fhwa.dot.gov/systemic/fhwasa13019/sspst.pdf 

` A brief description of the data analysis for the Road Safety Plans is available at: 

http://safety.fhwa.dot.gov/hsip/resources/fhwasa1102/data_mn.cfm 

` More information on Data-Driven Safety Analysis is available on the Every Day Counts website: 

http://www.fhwa.dot.gov/everydaycounts/edc-3/analysis.cfm 

For additional Jerry Roche John McFadden 

information, FHWA Office of Safety FHWA Resource Center 

please contact: 515-233-7323 410-962-0982 

Jerry.Roche@dot.gov John.Mcfadden@dot.gov

Every Day Counts (EDC), a State-based initiative of FHWA’s Center for Accelerating 

Innovation, works with State, local and private sector partners to encourage the adoption of 

proven technologies and innovations aimed at shortening and enhancing project delivery FHWA-14-CAI-057 

www.fhwa.dot.gov/everydaycounts