Data-Driven Safety

Analysis (DDSA) 

Using evidence-based tools to evaluate the current and future safety performance of 

roadways allows agencies to target investments with more confidence and reduce 

severe crashes on their system. 

Traditional crash and roadway analysis methods 

mostly rely on subjective or limited quantitative 

measures of safety performance. This makes it difficult 

to calculate safety impacts alongside other criteria 

when planning projects. Data-driven safety analysis 

(DDSA) employs newer, evidence-based models that 

provide state and local agencies with the means to 

quantify safety impacts similar to the way they do 

other impacts such as environmental effects, traffic 

operations and pavement life. 

The analyses provide scientifically sound, data-driven 

approaches to identifying locations and features 

with the highest potential for safety improvement. 

Agencies then execute the most beneficial projects 

with available resources to achieve fewer fatal and 

serious injury crashes. 

DDSA provides more reliable analysis than previous 

methods through the application of predictive and 

systemic tools for analyzing crash and roadway data. 

Through round four of Every Day Counts (EDC-4), 

this effort focuses on both predictive and systemic 

analyses—two types of data-driven approaches that 

state and local agencies can implement individually 

or in combination. 

Predictive analysis helps identify roadway sites with 

the greatest potential for improvement and quantify 

the expected safety performance of different project 

alternatives. 

Predictive approaches combine crash, roadway 

inventory and traffic volume data to provide 

more reliable estimates of an existing or proposed 

roadway’s expected safety performance. The results 

inform roadway safety management and project 

development decision-making. The data not only 

help agencies make better decisions, but also inform 

the public as to what safety benefits they can expect 

from their investment. 

Systemic analysis uses crash and roadway data 

in combination to identify roadway factors that 

correlate with particular crash types. 

Agencies have traditionally relied on crash history 

data to identify “hot spots,” or sites with high crash 

frequency. However, severe crashes are widely 

dispersed over road networks, and their location 

and frequency fluctuate over time. Systemic analysis 

identifies locations that have the greatest potential 
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.

www.fhwa.dot.gov/everydaycounts

Data-Driven Safety

Analysis (DDSA) 

for severe crashes, even if there is not a high crash 

frequency. Practitioners can then proactively apply 

low-cost countermeasures to those locations. The 

benefit is wider, but more targeted, safety investment. 

STATE OF THE PRACTICE 

To date, 75 percent of states are applying DDSA in 

one or more of their project development processes. 

This effort is a result of collaborative work by AASHTO, 

FHWA, the Transportation Research Board and industry 

over the past two decades. DDSA was originally 

promoted under the third round of EDC (EDC-3), and 

it continues under the fourth round (EDC-4) with an 

additional focus on broadening use among local 

agencies. 

BENEFITS 

` Informed Decision-Making. Predictive and systemic 

analyses improve on traditional decision-making 

approaches that rely on subjective and limited 

quantitative measures of safety performance. 

` Targeted Investment. Agencies use the analyses to 

optimize funding by selecting the most appropriate 

roadway features and project sites. 

` Improved Safety. DDSA offers a scientifically sound, 

data-driven approach to allocating resources that 

results in fewer fatal and serious injury crashes on 

the Nation’s roadways. 

For additional Jerry Roche 

information, FHWA Office of Safety please contact: 515-233-7323 

Jerry.Roche@dot.gov

DDSA TOOLBOX* 

Supporting information, informational videos and 

more can be found at the DDSA webpage: 

https://www.fhwa.dot.gov/innovation/

everydaycounts/edc_4/ddsa.cfm

EDC-4 Summit Breakout Session: Fall 2016 

https://www.youtube.com/watch?v=KH3QpnyJCN0

Predictive Analysis 

AASHTO Highway Safety Manual 

http://www.highwaysafetymanual.org

AASHTOWare Safety Analyst software 

http://www.safetyanalyst.org

Agile Assets Safety Analyst software 

https://www.agileassets.com/products/safety-analyst/

Crash Modification Factors Clearinghouse 

http://www.cmfclearinghouse.org

FHWA Interactive Highway Safety Design Model 

http://www.fhwa.dot.gov/research/tfhrc/projects/

safety/comprehensive/ihsdm/index.cfm

SPF Tool http://spftool.com/

Spreadsheet tools, including the Enhanced 

Interchange Safety Analysis Tool (ISATe) 

http://www.highwaysafetymanual.org/Pages/Tools.

aspx

Systemic Analysis 

FHWA Systemic Safety Project Selection Tool 

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

Roadway Safety Foundation United States Road 

Assessment Program (usRAP) software 

http://www.usrap.org/

*FHWA cites specific tools as examples, not as an endorsement of these tools 

over others. 

John McFadden 

FHWA Resource Center 

410-962-0982 

John.McFadden@dot.gov

www.fhwa.dot.gov/everydaycounts FHWA-16-CAI-013