Safety Analysis & Programs

Safety Analysis & Programs

Photo by Shane Chevalier, CDOT R1

Safety Analysis Information | Highway Safety Improvement Program | FASTER Safety Mitigation Program | Events

The Safety Analysis & Programs group is responsible for supporting the ongoing statewide efforts to improve traffic safety along all public roadways in Colorado through strategic data-driven approaches. Highway Safety Manual concepts are frequently applied by the group through the use of predictive crash models and crash modification factors. The group administers two major programs (Highway Safety Improvement Program and FASTER Safety Mitigation Program) that are devoted to improving safety through the reduction of crashes, most notably those that cause serious injuries or fatalities.

Safety Analysis Information

How is Safety Defined?

The efficient and responsible investment of resources in addressing safety problems is a difficult task. Since crashes occur on all highways in use, it is inappropriate to say of any highway that is safety or unsafe as road safety is a matter of degree. We have refined the assessment of the magnitude of safety problems through the use of Safety Performance Functions (SPF). The SPF reflects the complex relationship between traffic exposure measured in Average Daily Traffic (ADT), and crash count measured in crashes per year. The SPF models provide an estimate of the expected crash frequency and severity for a range of ADT among similar facilities.

Colorado Safety Performance Functions (SPF)

All dataset preparation was performed using CDOT's crash database. Crash history for each facility was prepared using the most recent five to ten years of available crash data. The ADT for each roadway and/or intersection approach (major and minor) over the five to ten years was entered into the same dataset. Each dataset is corrected for the regression to the mean bias using the Empirical Bayes (EB) procedure. This resulted in the SPF models for highway segments, intersections, ramp intersections. CDOT has developed maps to display the safety performance of our roadways, which could be found here.

Normative Baselines

The roadways and intersections were tested for the presence of patterns related to crash type, severity, direction of travel, road conditions, spatial distribution of crashes, time of day, and behavioral attributes. Pattern-recognition analysis is performed using normative percentages for diagnostics of safety problems for comparable roadways and intersections. These diagnostic norms were developed using the same data points as the SPF analysis.

Highway Safety Improvement Program (HSIP)

This federal aid program funds safety improvement projects that can achieve a significant reduction in traffic fatalities and serious injuries on all public roads. This program operates through data-driven analysis to support strategies with a goal toward zero deaths on Colorado roadways. 

FASTER Safety Mitigation (FSM) Program

On March 2, 2009, Colorado Gov. Bill Ritter signed SB09-108 into law. The Funding Advancement for Surface Transportation and Economic Recovery (FASTER) provides needed funds to address safety issues on Colorado roadways. As directed by the Colorado Transportation Commission, CDOT is responsible for implementing road safety projects on state highways using funds credited to the Highway User Tax Fund and allocated to the State Highway Fund. CDOT receives roughly 60% of the FASTER fines, fees, and surcharges that are maintained in the Highway User Tax Fund.

The commission directed CDOT to deliver a FASTER program, which is divided into the bridge, transit and safety. Safety is subdivided into the asset management use of FASTER safety funds and the FASTER Safety Mitigation (FSM) program. The FSM program is focused on mitigating documented safety hazards and preventing future crashes with specific goals of reducing highway crashes and the severity of highway crashes. 

Upcoming Traffic & Safety Engineering Branch Events

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Mission & Vision
  • Our mission is to strategically reduce traffic crashes and resulting deaths, injuries, and property damage, and improve the flow of traffic via traffic engineering principles.

  • Our vision is to become the state agency sought-out leader for applying traffic engineering principles to improve traffic safety and maximize the operations of the highway system, and the foremost resource for crash data, analysis, and engineering strategies - and mitigation for improving highway safety and operational efficiency.
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