Every Day Counts-4: CDOT Implements Data-Driven Safety Analysis to Reduce T
By Quentin Boose, Process Improvement Intern
January 4, 2019
CDOT’s project development process includes DDSA in the planning phase
The Federal Highway Administration’s (FHWA) Center for Accelerating Innovation recently completed its fourth Every Day Counts (EDC) initiative, a state based model to accelerate the development of proven innovations across transportation departments. According to FHWA, these ideas “provide an ‘On-Ramp to Innovation’ by developing, launching, and administering strategic innovation deployment throughout the country.”
The fourth installment of EDC innovations, deployed between 2017 and 2018, included Data-Driven Safety Analysis (DDSA), an innovation focusing on cutting edge methods to analyze crash and roadway data to predict safety impacts of transportation projects. The safety analysis is two fold: it applies predictive analysis and systematic measures. Predictive analysis includes using crash, roadway characteristics, and traffic volume data to estimate a new or existing highway project’s safety performance. Systematic measures use multiple data sources to target sections of roadway with severe crash potential, an enlargement of the traditional “hot spot” tracking, which only accounts for crash volume. One such measure is the Crash Prediction Module (CPM), a program that normalizes the crash frequencies over the crash rates and severities. This tool allows the Colorado Department of Transportation (CDOT) engineers to identify facilities with the greatest potential for safety improvement and also evaluate roadway alternatives and preliminary geometry. Since the implementation of this available technology, CDOT has designed more reliable intersections on a variety of projects, including the US 160/State Highway 550 Interchange and on Interstate-70 Avon from to Vail.
The primary use of DDSA is through modeling scenarios where meeting full roadway design standards isn't practical. “Data-Driven Safety Analysis has been applied or piloted, but mostly on an ad-hoc basis for some time now. If you only apply DDSA on design exceptions, then you are missing a world of opportunities,” said Emeka Ezekwemba of FHWA. To increase the prevalence of DDSA, CDOT has conducted awareness campaigns across the state spreading the importance of DDSA within the organization and to other local agencies.
After the successful roadshows, it was determined the safety analysis would be conducted by traffic engineers who can generate forecasted crash models. These models are in the process of being institutionalized early on in the project development process, establishing Data Driven Safety Analysis as a primary step in project planning. Jerome Estes, a CDOT Design Area Engineer, states that DDSA, “has fundamentally changed the highway design process, for the better, towards increased safety and overall value.”
In spring of 2019, CDOT plans to host a National Highway Institute training on the implementation of DDSA to increase awareness and provide the knowledge needed to institutionalize the process. Once DDSA is standardized, predictive crash models will be conducted concurrent with normal project development activities during the planning and geometric design phases. DDSA is poised to make roads safer throughout the state, improving upon the core CDOT Safety value.