Research, Development, and Technology Turner-Fairbank Highway Research Center 300 Georgetown Pike, McLean, VA 22101-2296

www.tfhrc.gov

Crash Modification Factors Needs

Assessment Workshop

SUMMARY REPORT

Executive Summary

The Federal Highway Administration (FHWA) hosted 

a Crash Modification Factor (CMF) Stakeholder 

Meeting to provide a forum for CMF stakeholders 

to communicate ongoing efforts and identify opportunities for future collaboration. CMF stakeholders 

represent two primary groups: the CMF user community (transportation agencies and practitioners) 

and the CMF research and development community 

(individuals and agencies who plan, fund, direct, and 

carry out CMF research). Bringing these stakeholders 

together provided an opportunity to share insights 

and resources to further advance the research and 

development of CMFs and related activities.

The meeting was arranged around five primary 

topic areas. The first was current CMF-related 

activities, which allowed time for each stakeholder 

to identify their roles, responsibilities, and current 

efforts with respect to the development and application of CMFs. The second topic of discussion was 

CMF research needs, which included a summary 

of the results of a CMF gap analysis. The third topic 

focused on resources (e.g., data) to support the 

development of CMFs. The fourth topic, advancing 

highway safety, focused on research methods, technologies, and innovation. The final discussion was 

a recap of the overarching themes and focused on 

future opportunities to advance the state of the 

practice. The remainder of this section provides further details on each of the topic areas, summarizing 

current CMF development efforts and highlighting 

key opportunities for the future. 

FHWA, the Transportation Research Board (TRB), 

and State transportation departments are the 

primary sponsors of research to develop CMFs. 

CMFs are developed through individual research 

projects, such as those under the National Cooperative Highway Research Program (NCHRP), 

which is a division of TRB. CMFs are also developed 

under a large FHWA effort, the Development of 

Crash Modification Factors (DCMF) Program. Most 

individual projects are subject-specific; CMFs are 

developed for a particular strategy or set of 

strategies. The objective of the DCMF Program is to 

develop numerous CMFs for diverse strategies. 

There is an opportunity for better coordination 

among these groups to avoid duplication of efforts.

Several other groups conduct crash-based research 

that may or may not result in the development of 

CMFs. These groups include the AAA Foundation 

for Traffic Safety (AAA-FTS), Insurance Institute for 

Highway Safety (IIHS), National Highway Traffic 

Safety Administration (NHTSA), and Federal Motor 

Carrier Safety Administration (FMCSA). For example, 

the IIHS has conducted several studies to estimate 

the safety effectiveness (i.e., CMFs) of strategies 

such as speed enforcement cameras, roundabouts, 

centerline rumble strips, and red-light-running 

cameras. The AAA-FTS developed the U.S. Road 

Assessment Program (usRAP), which includes “risk 

factors” to estimate the safety performance of a 

roadway based on the design and operational 

characteristics of that specific road.

FHWA Publication No.: FHWA-HRT-15-020

FHWA Contact: Roya Amjadi, HRDS-20, 202-493-3383, roya.amjadi@dot.gov
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CMFs serve a similar function as the risk factors 

in usRAP. There may be future opportunities 

to coordinate efforts with these groups to develop 

CMFs. There may also be opportunities to coordinate with or use the results of other safety or 

operational effectiveness studies to develop 

specific CMFs. The ultimate goal is for these groups 

to develop CMFs as part of their research to expand 

the use of their results. 

Outreach to safety stakeholders, particularly decisionmakers for planning and funding research, 

was identified as a critical component to advancing 

the development, use, and understanding of the 

importance of CMFs. FHWA, TRB, the Institute of 

Transportation Engineers (ITE), the Roadway Safety 

Foundation (RSF), and others currently play an 

active role in stakeholder outreach through various 

initiatives such as conferences, journals, webinars, 

and workshops. For example, ITE leadership has 

identified CMF needs through informal conversations with their members. There is an opportunity 

to expand and formalize ITE’s efforts, including 

coordination with FHWA and TRB. There is also a 

need to coordinate the prioritization of CMF needs, 

identification of training needs, identification of 

proper training mechanisms, and dissemination 

of results. RSF could be engaged to coordinate 

with decisionmakers on the need for and importance of CMFs.

The development and advancement of CMFs is 

dependent on the availability of quality data. Several 

databases are currently used to develop CMFs, 

including the Highway Safety Information System 

(HSIS), the Fatality Analysis Reporting System 

(FARS), and State and local roadway and crash 

databases. Other existing data sets may serve as 

resources, including the FMCSA analysis and information (A&I) online database and IIHS insurance 

data. There are also new and forthcoming databases 

that hold promise for developing CMFs, such as the 

Strategic Highway Research Program 2 (SHRP2) 

roadway information database and naturalistic driving data. In addition to current databases, there is a 

need for databases to support CMF development, 

including a mechanism to track new strategies and 

innovations so that CMFs can be developed in a 

timely manner.

In summary, there are many opportunities to 

advance the development, use, and understanding 

of CMFs by fostering partnerships with national 

organizations, other Federal agencies, and State 

and local partners. These partners provide an opportunity to better understand CMF needs, a source of 

data and sponsorship for research, and a mechanism for outreach to the vast CMF community.

Preface

The CMF Stakeholder Meeting was sponsored by 

FHWA’s DCMF Program. The DCMF Program was 

established in 2012 to address highway safety 

research needs for evaluating new and innovative strategies by developing reliable quantitative 

estimates of their effect on crash frequency and 

severity.

The ultimate goal of the DCMF Program is to save 

lives and reduce injuries by identifying new safety 

strategies that effectively reduce the frequency and 

severity of crashes and promote them for nationwide installation by providing measures of their 

safety effectiveness and benefit-cost ratios through 

research. As the first step toward this goal, a DCMF 

task, New Statistical Methodologies and Improving 

the Current Ones for Highway Safety Research, 

was conducted in cooperation with the American 

Statistical Association (ASA) in December 2012 to 

build a foundation for advancing research. This 

task will be continued through follow-up studies 

and by implementing a Marketing, Communication, 

and Outreach Plan targeting the statistician 

community for developing new expertise, technical 

tools, and innovative highway transportation specific methodologies.

The DCMF task CMF Gap Analysis, Research Needs, 

and Stakeholder Meeting presents the second step 

toward the overall goal of the DCMF Program. This 

effort included a gap analysis of CMFs, identification and prioritization of current and future CMF 

research needs, and a CMF Stakeholder Meeting to 
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communicate ongoing efforts and identify opportunities for future collaboration.

Background

FHWA hosted a CMF Stakeholder Meeting on May 

28, 2014, at the Turner-Fairbank Highway Research 

Center. The objectives of the CMF stakeholder meeting were as follows:

• Brief stakeholders about the DCMF Program, 

Evaluation of Low Cost Safety Improvements 

Pooled Fund Study (ELCSI-PFS), and CMF 

Clearinghouse, including activities, products, 

and how they are used.

• Brief CMF stakeholders on the FHWA findings 

of the DCMF task for identifying CMF gaps and 

research needs and seek feedback on these 

findings, current/near future related activities, 

and how stakeholders may partner and/

or share resources with FHWA for meeting 

current CMF research needs for selected high 

priority safety areas.

• Brief CMF stakeholders on the FHWA 

findings of the DCMF task New Statistical 

Methodologies and Improving the Current 

Ones for Highway Safety Research for building 

a sound foundation for advancing highway 

safety research and seek feedback on these 

needs and activities and how they may partner 

and/or share resources with FHWA for meeting 

future CMF research needs.

• Obtain information on CMF-related efforts 

being conducted by stakeholders, including: 

1) safety concerns and how they are/were 

measured or validated through data, 2) innovative approaches and tools/technologies 

implemented to address their safety 

concerns, and 3) possible future efforts 

and partnerships for advancing highway 

safetyresearch, new strategy developments, 

and technology innovations.

• Identify action items to prepare solid ground 

for future CMF research in separate categories 

(e.g., data collection and improvements, 

statistical methodologies, new strategy 

developments, innovative science and 

technologies, and technology transfers), and 

identify partners for carrying these identified 

actions forward. This objective may include 

an introduction to planned future DCMF and 

stakeholder activities.

• Encourage CMF-related communications 

and partnering that will advance these 

objectives, and include an action item for 

direct communication and its frequency for 

stakeholder’s updates/exchange to FHWA.

Working toward these objectives, the project team, 

in consultation with FHWA, planned a 1-day CMF 

stakeholder meeting to bring together members 

from both the CMF user community and CMF 

research and development community, which are 

described as follows:

• CMF User Community: This group 

includes the practitioners who incorporate 

CMFs into their safety analyses and apply 

them to their projects; personnel from State 

transportation departments are key members 

of this group. There are 38 State transportation 

departments that provide technical 

feedback on safety improvements to the 

DCMF Program and implement new safety 

improvements to facilitate evaluations. 

These States are members of the ELCSI-PFS 

that functions under the DCMF Program. 

The list of participating State transportation departments and their primary contact 

is provided in table 4 in appendix A.

• CMF Research and Development Community:

This group includes the agencies and individuals who plan, fund, direct, and carry out the 

research and development of CMFs and activities related to their application and prioritization. Each community has insight and resources 

that may be shared to further advance the 

research and development of CMFs and related 

activities. A list of United States Department of 
4

Transportation (USDOT) and partner agencies 

is provided in table 6 in appendix A, along with 

their primary contact.

Enhancing communication and collaboration 

among these groups will help streamline future 

safety efforts related to the research, development, 

and application of CMFs. Table 4 and table 6 in 

appendix A represent an initial list of CMF stakeholders. The intent is to help facilitate communication and coordination among CMF stakeholders. 

The contact lists in table 4 and table 6 in appendix A 

should be updated regularly and expanded over 

time as other stakeholders are identified. 

Organization of White Paper 

This summary report focuses on the outcomes 

and feedback from the CMF stakeholder meeting. 

The detailed agenda is included in appendix B. The 

meeting was arranged around the following topics, 

and this summary report follows a similar flow: 

• CMF-related activities.

• CMF gap analysis and research needs.

• Resources to support DCMF efforts.

• Advancing highway safety—research methods, 

technologies, innovation. 

• Looking to the future.

CMF-Related Activities

This section provides a brief summary of information exchange and related activities conducted by the 

various CMF stakeholders in the CMF Stakeholders 

Meeting.

FHWA Office of Safety Research & 

Development (R&D)

Roya Amjadi provided an overview of the CMFrelated activities conducted by the FHWA Office of 

Safety R&D. The primary efforts include hosting 

data, conducting CMF research, and encouraging 

innovation. A summary of these efforts is as follows:

• Data: The FHWA Office of Safety R&D sponsors 

and houses HSIS, a multistate database of 

select States that contains crash, roadway, 

and traffic volume data. Figure 1 identifies the 

active and historical States contributing data 

to HSIS. CMF researchers can request data 

from HSIS in support of their efforts to develop 

Figure 1. HSIS States.
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CMFs or advance the science of CMFs. The data 

are available free of charge, and additional 

information about HSIS can be found at http:// 

www.hsisinfo.org. The FHWA Office of Safety 

R&D is also establishing the Safety Training 

and Analysis Center (STAC), which will provide 

support to the research community and State 

transportation departments in using data from 

SHRP2. The SHRP2 data will be available in 

two components: 1) a Roadway Information 

Database (RID), and 2) a Naturalistic Driving 

Study (NDS) database. Additional information 

on the STAC is available at http://www.fhwa.

dot.gov/research/resources/stac.cfm. 

• CMF Research: The FHWA Office of Safety 

R&D encourages and facilitates communication, coordination, and collaboration with and 

among State transportation departments and 

other stakeholders to conduct CMF and related 

research. Specifically, they sponsor research to 

evaluate the safety effect (i.e., develop CMFs) 

of existing, new, and innovative strategies 

by working with the State transportation 

departments and researchers to collect data for 

existing strategies (retro-respective study), or 

install new safety strategies and then collect data 

for evaluations (build-to-evaluate study). They 

are the lead agency for the DCMF Program as 

well as the ELCSI-PFS, which includes 38 State 

members as shown in figure 2. At the time of 

this report, the FHWA Office of Safety R&D had 

sponsored the evaluation and development of 

CMFs for more than 40 strategies. Under efforts 

such as the DCMF Program, the FHWA Office of 

Safety R&D also sponsors research and efforts 

Figure 2. ELCSI-PFS participants. 
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to improve statistical analysis methods used 

to develop CMFs and efforts to network and 

cooperate with CMF stakeholders to advance 

safety research.

• Encourage Innovation: The FHWA Office 

of Safety R&D encourages innovation by 

supporting research and development of 

strategies before large-scale deployment. 

This is facilitated through their human factor 

labs, including a large-scale highway driving 

simulator, a mini-sim driving simulator, and 

a sign lab. The human factors lab is able to 

support research that originates within and 

outside the FHWA Office of Safety R&D. 

Additional information on the human factors 

lab is available at http://www.fhwa.dot.gov/

research/tfhrc/labs/humanfactors/index.cfm.

FHWA Office of Safety

Karen Scurry provided an overview of the CMFrelated activities conducted by the FHWA Office of 

Safety. In general, the FHWA Office of Safety sponsors activities related to both the application and 

development of CMFs, including the development 

of the CMF Clearinghouse, CMF-related guidance, 

and CMF-related training. They are also working to 

coordinate outreach efforts to improve the quality of 

CMFs. A summary of these efforts is as follows:

CMF Application Efforts

• CMF Clearinghouse: This is a one-stop shop 

for CMFs and related resources. The Web site 

shown in figure 3 was established to provide 

a regularly updated online repository of CMFs. 

It serves as a search engine, allowing users to 

search for CMFs for a specific countermeasure. 

The CMF Clearinghouse summarizes published 

information on each CMF, including how it was 

developed (e.g., study design, sample size, 

and source of data) and what its statistical 

properties are (e.g., standard error). In addition 

to the CMFs, 10 there are several CMF-related 

Figure 3. CMF Clearinghouse (http://www.cmfclearinghouse.org).
7

resources linked from the CMF Clearinghouse 

at http://www.cmfclearinghouse.org. 

• CMFs in Practice: This is a series of guides 

that illustrate the value and demonstrate the 

practical application of CMFs in the project 

development process. The CMFs in Practice

series includes five separate guides that identify 

opportunities to consider and quantify safety 

in specific activities, including: 1) Roadway 

Safety Management Processes, 2) Road Safety 

Audits, 3) Design Decisions and Exceptions, 

4) Development and Analysis of Alternatives, 

and 5) Value Engineering. Each guide includes 

a step-by-step demonstration of how CMFs 

can be applied in the specific activity, a case 

study to show real-world application of 

CMFs, discussion of potential challenges in 

applying CMFs, and opportunities to overcome 

those challenges. Additional information is 

available at http://safety.fhwa.dot.gov/tools/crf/

resources/cmfs. 

• National Highway Institute (NHI) Course 

380093 (Application of CMFs): The FHWA 

Office of Safety partnered with NHI to develop 

this introductory course on CMFs. After 

completing the course, participants should be 

able to do the following:

• Explain how CMFs are used to estimate the 

safety effects of highway improvements.

• Apply CMFs to compare and select 

highway safety improvements.

Additional information is available at http://

www.nhi.fhwa.dot.gov. 

• NHI Course 380094 (Science of CMFs): The 

FHWA Office of Safety partnered with NHI to 

develop this advanced course on CMFs. After 

completing the course, participants should be 

able to do the following:

• Explain the concepts of CMFs and the 

measurement of safety.

• List and describe important statistical 

issues that affect safety research.

• Describe and compare three methodologies

for evaluating the safety effect of a 

countermeasure.

• Select the most appropriate CMF for a 

given application.

Additional information is available at: http://

www.nhi.fhwa.dot.gov. 

CMF Development Efforts

• A Guide to Developing Quality CMFs: This 

guide provides direction to those interested 

in developing CMFs. It opens with a general 

discussion of CMFs, including definitions, 

purpose and application, and general issues 

related to CMFs. The document identifies 

several methodologies for developing CMFs, 

including an overview of each method, sample 

size considerations, strengths, and weaknesses. 

It also provides a process for selecting the most 

appropriate method. The guide is shown in 

figure 4, and additional information is available 

at http://www.cmfclearinghouse.org/collateral/

CMFGuide.pdf.(1)

Figure 4. A Guide to Developing Quality Crash 

Modification Factors.
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• CMF Development Training: The FHWA 

Office of Safety is again partnering with NHI 

to develop a course that will guide participants 

through the CMF development process. At the 

time of this report, the course development had 

just started, and the final course is expected 

by June 2015. After completing the course, 

participants should be able to do the following:

• Identify the various study designs used 

to develop CMFs, their data needs, and 

associated strengths and limitations.

• Select an appropriate study design based 

on the resources and quantity/quality of 

data available.

• Apply various methodologies to develop 

CMFs and assess the quality of the results.

• Document the appropriate elements of a 

CMF development effort.

• Coordinating Outreach Efforts: The FHWA 

Office of Safety is currently working to improve 

the quality of CMFs by coordinating outreach 

efforts. In support of this effort, they are working 

to develop a draft outreach strategy that will 

include standardized Request for Proposal (RFP) 

language for CMF research sponsors, sharing 

guidelines for developing CMFs, sharing 

information on paper reviewers and research 

sponsors, hosting TRB/NCHRP webinars, and 

providing training and technical assistance. 

FHWA Resource Center

Patrick Hasson provided an overview of the CMFrelated activities conducted by the FHWA Resource 

Center Safety and Design Technical Service Team. 

In general, the FHWA Resource Center assists with 

technology deployment and provides technical assistance. The following is a summary of these efforts:

• Technology Deployment: This includes 

packaging new information and delivering 

it to customers and partners. Examples 

include Highway Safety Manual (HSM) training courses such as the HSM for locals, 

incorporating CMFs into existing courses, and 

promoting technologies and strategies such 

as roundabouts.

• Technical Assistance: This involves 

responding to requests and special needs of 

customers and partners. For example, the 

Resource Center may be called upon to help 

examine alternatives that will provide the best 

safety results from investment.

The FHWA Resource Center works in close partnership with FHWA Headquarters and Office of Safety 

R&D to develop and deliver the best products and 

services possible to meet the safety challenges in 

the United States. Examples of coordination efforts 

include the Joint Strategic Plan and tactical roadmaps and spending plans.

FMCSA

William Bannister provided an overview of the 

CMF-related activities conducted by the FMCSA. In 

general, the FMCSA has not developed CMFs 

in the past because their safety initiatives are 

not roadway-specific but company-, vehicle-, and 

driver operation-related. They do, however, collect 

and analyze data to evaluate crash risk factors. The 

following is a summary of their efforts:

• Data: There are more than 500,000 interstate 

freight carriers, 12,000 interstate passenger 

carriers, and 15,000 intrastate hazardous 

materials carriers registered with FMCSA, with 

more than 3 million drivers and 4 million trucks 

and buses. Data are collected annually from 

nearly 4 million annual roadside inspections, 

mostly by State personnel; 10,000 to 30,000 

warning letters and 18,000 to 20,000 motor 

carrier investigations, mostly done by FMCSA 

safety investigators; and 130,000 FMCSAreportable crashes, submitted by States from 

police accident reports. They have established 

a robust data quality program to continually 

evaluate and improve the data, including a 

State Safety Data Quality (SSDQ) map. 

Specifically, FMCSA uses nine data quality 

performance measures to assess the timeliness, 

completeness, and accuracy of inspection and 

crash data reported by the States. The SSDQ 

map has been a real incentive to the States to 

achieve and maintain “green” status.
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• Data Analysis: FMCSA uses data to identify

individual commercial motor carriers (companies) who present a safety risk. Their 

enforcement program—Compliance, Safety, 

Accountability (CSA)—uses data to prioritize 

individual carriers for inspections or investigations. FMCSA also conducts extensive 

analysis to determine which violations of the 

Federal Motor Carrier Safety Regulations have 

the strongest relationship to crash risk, as well 

as the relationship between past crashes and 

future crash risk. Similar to safety performance 

functions, they have developed algorithms 

with weights assigned to each violation or 

crash type and further weighting based on 

how “old” the data are to produce a scoring 

system to rank carrier safety performance 

with respect to their “peers.” The data analysis 

is used to support rulemaking, performance 

measurement, and outreach programs.

• Reporting: FMCSA compiles data in their 

Safety Measurement System (SMS) and publishes analysis results on their A&I Web site, 

where it is publicly available. The motor carriers 

have access to their respective detailed data, 

including personal identifying information such 

as driver license numbers. Other users such as 

shippers, freight brokers, insurance companies, 

safety advocacy groups, the press, and the 

general public can view the SMS data on all 

carriers in the system.

More in line with CMFs, FMCSA has developed the 

following two models to assess the effectiveness of 

its safety programs:

• Roadside Intervention Effectiveness 

Model: For all motor carriers that received a 

roadside inspection, this model estimates 

crash reduction to determine the impact of the 

intervention. Different types of violations are 

assigned different crash risks, time periods of 

effectiveness, and correction rates based on a 

violation severity assessment. The reductions 

in crashes are combined for all carriers, and 

an estimate of crashes avoided, injuries 

prevented, and lives saved are calculated.

• Carrier Intervention Effectiveness Model:

This model employs a before-after comparison 

of crash rates for motor carriers receiving 

any one of the types of CSA enforcement 

investigations or warning letters employed by 

FMCSA. The carriers are grouped by size to 

account for differences in operations. All data 

are assessed for errors and outliers, which are 

removed. Results are then tested for statistical 

significance. The model calculates the change 

in crash rates for all carriers not receiving an 

intervention and subtracts any improvement 

in crash rates for this comparison group from 

the change calculated for those getting an 

intervention in an attempt to isolate the change 

attributable to the interventions. This modified 

change in crash rates for those receiving an 

intervention is used to then calculate crashes 

avoided, injuries prevented, and lives saved.

NHTSA

Kristie Johnson provided input for the meeting, 

highlighting NHTSA’s related efforts. In general, 

NHTSA focuses on countermeasures to address 

driver behavior issues. While they do not develop 

CMFs per se, there is an opportunity to coordinate 

efforts and promote effective strategies along with 

the associated safety impact (CMF or otherwise). The 

following is a summary of NHTSA’s related efforts:

• Countermeasures that Work: This guide 

is published biennially and serves as a basic 

reference to assist State Highway Safety Offices 

(SHSO) in selecting effective, evidence-based 

behavioral countermeasures for traffic safety 

problem areas. The safety problem areas 

include alcohol-impaired and drugged driving; 

seat belts and child restraints; aggressive 

driving and speeding; distracted and drowsy 

driving; motorcycle safety; young drivers; older 

drivers; pedestrians; and bicycles. The guide 

serves the following purposes:

• Describes major strategies and countermeasures that are relevant to SHSOs.

• Summarizes countermeasure use, effectiveness, costs, and implementation time.
10

• Provides references to the most important

research summaries and individual 

studies.

• Pedestrian and Bicyclist Countermeasure 

Primer for SHSOs: Countermeasures that 

Work is limited to behavior-focused countermeasures that States can fund with grant funds 

distributed by NHTSA. While it is appropriate 

for SHSOs to focus on behavior-based 

countermeasures eligible for funding, the most 

effective safety programs are comprehensive, 

integrating infrastructure and engineering 

countermeasures with outreach, education, 

and enforcement. This guide helps raise 

awareness of engineering strategies targeting 

pedestrians and bicyclists that are proven 

to be effective at reducing pedestrian and 

bicyclist injuries and fatalities. Having a basic 

knowledge and awareness of engineering 

countermeasures and relevant jargon allows 

decision makers to be mindful of what is 

already in place in their community and permits 

more effective communication among safety 

professionals. 

• Effect of Electronic Device Use on Pedestrian Safety: This study will quantify the 

impacts of electronic device use on pedestrian 

safety. At the time of this report, the study was 

underway and included the following tasks:

• Review literature on pedestrian and driver 

device use and distraction as it relates 

to pedestrians’ risk of injury or death in 

traffic conflicts with motor vehicles.

• Collect naturalistic observations to 

quantify distraction related to drivers’ 

and pedestrians’ use of electronic devices 

during pedestrian-vehicle interactions.

• Collect and analyze data from pedestrianvehicle crashes to quantify the frequency 

and severity of crashes that involve 

pedestrians’ and drivers’ use of electronic 

devices.

National Academies of Sciences (NAS)

Bernardo Kleiner and David Plazak provided an 

overview of the CMF-related activities conducted 

by NAS. TRB is the primary division associated with 

CMF-related activities within NAS. TRB provides 

leadership in transportation innovation and 

progress through research and information 

exchange. TRB is supported by State transportation 

departments, Federal agencies, and other organizations and individuals interested in the development of transportation. The following is a summary 

of TRB’s CMF-related efforts:

• Technical Activities: The TRB Technical 

Activities Division supports standing 

committees and task forces, organizes the 

TRB Annual Meeting and other conferences 

and workshops, and conducts field visits to 

transportation agencies, organizations, and 

research institutions. There are two standing 

committees that are heavily involved in CMFrelated activities: 1) ANB20: Safety Data, 

Analysis, and Evaluation, and 2) ANB25: 

Highway Safety Performance. These committees are involved in the identification 

and prioritization of research needs, the 

development of research needs statements, 

and the marketing of completed research.

• Studies and Special Programs: The TRB 

Studies and Special Programs Division 

convenes specially appointed expert committees to conduct policy studies and program reviews, maintains the Transportation 

Research Information Services database, provides library services, prepares synthesis 

reports on behalf of the Cooperative Research 

Programs, and manages the Innovations 

Deserving Exploratory Analysis programs.

• Cooperative Research Programs: The TRB 

Cooperative Research Programs Division 

manages NCHRP, the Transit Cooperative 

Research Program (TCRP), the Airport Cooperative Research Program, the National 

Cooperative Freight Research Program, and 
11

the Hazardous Materials Cooperative Research 

Program. Many CMF development efforts 

and related research are funded through 

NCHRP projects.

• SHRP2: The TRB SHRP2 Division manages a 

targeted, short-term, results-oriented program 

of contract research, designed to advance 

highway performance and safety for U.S. 

highway users. Two databases are being 

developed under SHRP2: the RID and the NDS 

databases. The RID contains existing data taken 

from Esri and State roadway inventories, as 

well as data recently collected on approximately 

12,500 centerline mi from six study States. 

The NDS database includes data representing 

normal driving habits from more than 

3,100 participants of various ages across the 

country. Included in the NDS database are more 

than 5 million trips, 49 million travel miles, and 

1.4 million driving hours, making this the largest 

naturalistic driving study ever undertaken. 

These databases are further described in 

table 6 through table 9 in appendix C and 

will be used to support future research related 

to CMF development and improvement. 

American Association of State Highway 

Transportation Officials (AASHTO) 

Kelly Hardy provided an overview of the CMFrelated activities conducted by AASHTO. In general, 

AASHTO represents highway and transportation departments in the 50 States, the District of 

Columbia, and Puerto Rico, serving as a liaison 

between State transportation departments and 

the Federal government. AASHTO is a standardssetting body that publishes specifications, test 

protocols, and guidelines that are used in highway design and construction throughout the United 

States. The following is a summary of CMF-related 

efforts:

• HSM: The HSM is an AASHTO publication, 

but AASHTO works closely with the FHWA 

Office of Safety and the TRB Highway Safety 

Performance Committee on issues related 

to the HSM. The HSM presents a variety of 

methods for quantitatively estimating crash 

frequency or severity on various facility types. 

CMFs are used in the predictive methods from 

part C of the HSM, and there is an entire section 

of the HSM (part D) that presents CMFs for 

various countermeasures. Part D is divided into 

five chapters, presenting CMFs separately for 

roadway segments, intersections, interchanges, 

special facilities, and road networks. 

• Standing Committee on Highway Traffic 

Safety (SCOHTS): SCOHTS and the associated 

Subcommittee on Safety Management 

(SCOSM) identify and prioritize safety research 

needs, including research related to CMF 

development. Specifically, research needs 

statements are developed by members of the 

research community (within and outside of 

SCOHTS), and members of SCOSM review and 

assess the merit of those statements. The topranking statements are then submitted to the 

AASHTO Standing Committee on Research for 

funding. Those statements selected for funding 

are then included in the next cycle of NCHRP 

projects.

• AASHTO Innovation Initiative: This initiative 

was formerly known as the Technology 

Implementation Group (TIG). Members 

involved in this initiative identify products or 

processes likely to yield significant economic 

or qualitative benefits. It is a systematic 

approach for putting new technologies into 

day-to-day practice, similar to the FHWA 

Every Day Counts (EDC) initiative and FHWA 

Proven Countermeasures. Specifically, this 

initiative designates “champions” to promote 

technologies, which can then be implemented 

and evaluated. Examples of technologies 

promoted under the former TIG include severeduty crash attenuators, sequential flashing 

warning lights for work zones, grade crossing 

electronic document management systems, 

linear referencing systems, cable median 

barriers, road safety audits, and intelligent 

transportation systems in work zones.
12

AAA-FTS 

Doug Hardwood, MRI Global, provided an overview 

of AAA-FTS’s efforts on behalf of Peter Kissinger 

from AAA-FTS. While AAA-FTS has not developed 

CMFs by name, they have developed usRAP, which 

is a planning-level tool to help highway agencies 

better understand the risk of crashes on specific road 

segments. The usRAP tool incorporates risk factors, 

which are equated to CMFs, to quantify the change 

in risk associated with a change in a given roadway 

characteristic. The following is a summary of two 

components of the usRAP tool:

• Risk Mapping: The usRAP risk mapping 

protocol assists highway agencies in 

characterizing the risk of crashes on specific 

road segments based on crash and traffic 

volume data. Agencies can use the usRAP 

risk maps to see how well their road system 

is performing and direct resources rationally 

toward systematic improvement of their road 

system. 

• Safer Roads Investment Protocol: The 

usRAP safer roads investment protocol is 

available to help plan a cost-effective program 

of highway infrastructure improvements to 

enhance safety. The safer roads investment 

plan provides preliminary recommendations 

of countermeasures for implementation at 

specific locations to improve safety. An advantage of the usRAP Tools software is that 

the safety plans are based on roadway characteristics data and do not require detailed, 

site-specific crash data. 

IIHS

Wen Hu provided an overview of the CMF-related 

activities conducted by IIHS. In general, IIHS is 

dedicated to reducing losses—deaths, injuries, and 

property damage—from crashes on the Nation’s 

highways. Their sister organization, the Highway 

Loss Data Institute, shares and supports the mission 

through scientific studies of insurance data representing the human and economic losses resulting 

from the ownership and operation of different types 

of vehicles and by publishing insurance loss results 

by vehicle make and model. Both organizations are 

wholly supported by auto insurers and guided by the 

Haddon Matrix, which identifies interactions among 

the driver, vehicle, and environment during precrash, crash, and post-crash events. CMFs are most 

directly applicable to the environment during the 

pre-crash and crash stages. For example, roundabouts, posted speeds, and other design features 

affect the likelihood of a crash. Roadside features 

such as breakaway devices and roadside barriers 

affect the severity of a crash. The following is a summary of CMF-related efforts:

• Roundabouts: IIHS conducted a comprehensive safety evaluation of roundabouts 

and concluded that the conversion of 

stop- and signal-controlled intersections 

to roundabouts could result in a 40 percent 

reduction in all crashes, an 80 percent reduction 

in injury crashes, and a 90 percent reduction in 

fatal and incapacitating injury crashes at the 

treated locations. Furthermore, they noted that

if 10 percent of signalized intersections in the 

United States were converted to roundabouts, 

then the following changes would occur:

• Approximately 46,000 crashes would have 

been prevented in 2012, including 184 fatal 

crashes and 31,000 injury crashes.

• Vehicle delays would have been reduced 

by more than 900 million h.

• Fuel consumption would have been 

reduced by more than 600 million gal.

• Red Light Cameras: IIHS conducted a study of 

red-light cameras in Arlington, VA, to evaluate 

their safety effectiveness. They observed large 

reductions in red-light violations that occur 

late in the red interval (i.e., 1.5 s or longer after 

onset of red light) compared to the number 

of expected violations without cameras. They 

also conducted a study of red-light cameras in 

Oxnard, CA. They reported reductions in total, 

injury, and right-angle crashes, with substantial 

reductions (nearly 70 percent) in right-angle 

injury crashes.

• Speed Cameras: IIHS studied the safety 

effects of speed cameras in 2003 and 

2008, including the cities of Scottsdale, AZ; 
13

Montgomery County, MD; and Washington, DC. 

In all three locations, they observed reductions 

in the proportion of vehicles exceeding the 

speed limit by more than 10 mi/h after camera 

enforcement. Compared to other sites, there 

was an 88 percent reduction in Scottsdale, a 

70 percent reduction in Montgomery County, 

and an 82 percent reduction in Washington, DC.

• Speed Limits: In 1999, IIHS published a study 

on the safety impacts of the repeal of the 

national maximum speed limit. 

• Ongoing Research: Other ongoing research 

topics related to the roadway environment 

include the following:

• A national study of the effects of speed 

limit changes on fatal crash rates.

• A study of the effects of stop-sign cameras 

and crosswalk cameras on violations.

ITE

Ed Stollof provided an overview of the CMF-related 

activities conducted by ITE, an international educational and scientific association of transportation 

professionals who are responsible for meeting 

mobility and safety needs. Its members represent a 

wide cross-section of CMF stakeholders, including 

academia/education, consultants, the Federal government, State governments, and local governments. These members conduct CMF-related 

research, develop and distribute CMFs, and use 

CMFs on a daily basis. The following is a summary 

of CMF-related efforts:

• Education: Through surveys and existing 

professional development/training, ITE has 

determined that many practitioners and 

younger members lack knowledge of basic 

statistics, appropriate methodologies, and how 

to use CMFs.

• CMF Distribution: ITE shares information on 

CMFs through ITE Journal articles and HSIS 

supplements; the Journal of Transportation of 

the Institute of Transportation of Engineers; 

training and workshops; professional 

development; district, section and chapter 

meetings; and its annual meetings. Examples 

include the following:

• ITE Alaska Section Transportation Safety 

Committee: Focuses on best practices that 

incorporate the HSM, CMF development, 

and safety performance function 

calibration. This provides a forum for 

discussion.

• FHWA-MODOT-LTAP-KCITE-OCITECMCITE: Workshop on the Missouri 

Guidebook updating Introduction to Traffic 

Practices: A Guidebook for Local Agencies 

(2013). Included section on HSM and use 

of CMFs. 

• CITE Chapter (Toronto, Canada, Workshop): University of Manitoba ITE Chapter 

hosted a CMF Clearinghouse seminar.

• Everyday Practice: ITE members use CMFs 

in all phases of the project development 

process, including transportation planning, 

environmental documentation, alternatives 

analysis, investment decisions and cost benefit/

analysis, preliminary engineering and design, 

and road safety audits.

• Identifying CMF Needs: ITE has compiled a 

list of CMF needs based on years of member 

conversations. The following is a summary of 

identified CMF-related needs.

• Context matters: CMF users are not only 

designing curves or alternative intersections. They are planning, designing, and 

operating facilities within the context 

of communities. They are designing for 

Complete Streets and Sustainable 

Communities. Therefore, CMFs with 

appropriate detail to describe the context 

would be most beneficial. Applicable 

context may include area-type (e.g., 

urban/downtown core, urban, suburban 

town center, suburban low density, rural/

suburban transition, and rural), land use 

patterns, regional differences, traffic safety 

culture/cultural differences (e.g., differences 
14

in seatbelt laws, alcohol laws, and posted 

speeds), and sociodemographic factors.

• CMFs are needed for many more 

pedestrian, bicycle, and multimodal 

strategies, including bicycle lanes, cycle 

tracks (one- and two-way), mid-block 

pedestrian crossings, by area-type, by type 

(e.g., basic painted crosswalk, pedestrian 

hybrid beacon, median refuges), addition 

of “x” bus stops with safe pedestrian 

crossings within “x” mile segment, and 

transit signal priority systems (intelligent 

transportation systems (ITS) operations).

• CMFs are needed for design elements 

related to Complete Streets and 

Sustainable Communities.

• CMFs are needed for additional traffic 

engineering/operational features, including adaptive signal control technology, 

traffic signal optimization/retiming, 

illumination by area type (e.g., increase 

from base to point 1 or increase from 

base to point 2), speed reduction (by area 

type) such as urban centers on main streets 

(e.g., from 30 to 20 mi/h, from 35 to 25 mi/h), 

and access management (e.g., reduction in 

density of unprotected left turns or reduction in density of driveways).

• CMFs are needed for ITS/technology 

strategies, including speed cameras by 

area type (e.g., schools versus other 

urban, suburban, freeways, arterials), redlight cameras, road weather information/

management systems, and dynamic 

message signs.

• Future research may include the 

development of CMFs for vehicle-toinfrastructure (V2I) and vehicle-tovehicle (V2V) technologies. Cooperative 

Intersection Collision Avoidance Systems 

is an example of V2I technology. Examples 

of V2V include blind-spot warnings, 

do-not-pass warnings, intersection 

warnings, forward-collision warnings, and 

rollover warnings.

International Efforts

Patrick Hasson provided an overview of international 

CMF-related activities. In general, the international 

community is actively developing CMFs and 

conducting CMF-related research. Many countries 

are facing similar issues in terms of methodology, 

transferability, and applicability of CMFs. The following is a summary of CMF-related efforts:

• International Transport Forum (ITF): The 

ITF is a forum at the Organization for Economic 

Cooperation and Development, an intergovernmental organization with 54 member 

countries. ITF acts as a strategic think tank 

that convenes at an annual summit of ministers along with leading representatives 

from industry, government, and academia. 

ITF’s Research Centre gathers statistics and 

conducts cooperative research programs, 

and the research findings are discussed at the 

annual summit and widely disseminated to 

support policymaking in member countries. 

In 2012, ITF published Sharing Road Safety: 

Developing an International Framework for 

Crash Modification Functions.(2) This report 

focuses on international collaboration to 

promote the rigorous development of 

CMFs and increase the potential for transferability of CMFs among countries. The 

report does the following: 1) identifies 

issues related to the development and 

application of CMFs, 2) evaluates obstacles 

related to international collaboration on 

the development of CMFs, 3) identifies 

opportunities to promote collaboration, 

4) examines the international transferability 

of CMFs, and 5) presents a theoretical basis 

for assessing countermeasure effectiveness 

in a framework that is based on the quality 

and consistency of individual studies. 

• International CMF Clearinghouse: Hasson 

noted that the international safety community 

is interested in developing an International 

CMF Clearinghouse, similar to the one 

developed in the United States.
15

State Transportation Department Efforts

State transportation departments are actively 

involved in the entire spectrum of CMF-related 

activities. The following is a high-level overview 

of State transportation department involvement in 

CMF-related activities:

• State transportation departments help identify 

and prioritize CMF development needs.

• State transportation departments implement 

strategies and collect data that can then be 

used to support the development of CMFs and 

CMF-related research.

• State transportation departments provide 

funding through their Strategic Planning and 

Research funds to support NCHRP projects 

to develop national CMFs and conduct CMFrelated research.

• State transportation departments serve on 

NCHRP panels to oversee and guide CMFrelated research projects.

• State transportation departments fund other 

research projects to develop state-specific CMFs.

• State transportation departments develop 

CMFs in-house.

• State transportation departments apply CMFs 

throughout the project development process 

to support decisionmaking.

CMF Gap Analysis and ResearchNeeds Prioritization

Daniel Carter and Frank Gross presented the results 

of a CMF gap analysis and research-needs prioritization. The gap analysis and prioritization was a 

multistep process, including an inventory of existing CMFs and ongoing research, the identification 

of research needs, and the prioritization of research 

needs. These three steps are described below.

Inventory of Existing CMFs and Ongoing 

Research

In order to identify the gaps in CMF research, it is 

crucial to begin with a firm understanding of what 

CMF knowledge currently exists and what research 

is in progress to develop additional CMFs. This effort 

included a detailed query of the CMF Clearinghouse 

and TRB’s Research in Progress (RiP) database. 

Using these two sources, a comprehensive database of existing and forthcoming CMF knowledge 

was developed. 

The applicability of CMFs is an important consideration in the identification of knowledge gaps. For 

example, a CMF may be available for roundabouts, 

but if that CMF only applies to the conversion of rural, 

stop-controlled intersections to roundabouts, then 

there are clear gaps (e.g., a CMF would be needed 

for urban, stop-controlled conversions as well as 

rural and urban signalized conversions). As such, 

the inventory of existing and ongoing CMF research 

included several details related to the applicability. 

Where available and applicable, the following details 

were identified and included in the inventory:

• CMF identification number.

• Star quality rating.

• Countermeasure category.

• Countermeasure subcategory.

• Countermeasure name.

• Combined countermeasure name.

• CMF or CMFunction.

• Cost/benefit ratio or other benefit.

• Crash type.

• Crash severity.

• Crash time of day.

• Roadway type.

• Number of lanes.

• Area type.

• Intersection type.

• Intersection geometry.

• Traffic control type.

• Prior condition.

• Inclusion in HSM.
16

• State/municipality.

• Country.

• Type of study methodology.

• Standard error.

• Sample size (total).

• Sample size (before).

• Sample size (after).

In total, more than 4,700 existing/forthcoming CMFs 

were identified for the inventory. The inventory provided a starting point for identifying and prioritizing 

CMF research needs. Beyond this effort, the inventory of CMFs provides a structure and template for 

tracking ongoing CMF-related research. It will be 

important to update this resource periodically to 

assist with future CMF prioritization efforts.

Identification of Research Needs and Gaps

Current CMF research needs were identified by 

examining a variety of sources. A recent NCHRP 

study, NCHRP Project 17-48: Highway Infrastructure 

and Operations Safety Research Needs, provided a 

starting point.(3) The NCHRP study developed a list 

of general safety research needs, including CMF 

research needs, based on a review of the sources 

identified in table 1. Note that several of the sources 

have not been updated since the time of the study, 

while others had to be re-reviewed for the latest 

CMF-related needs.

The CMF-related research needs were extracted from 

the list developed under NCHRP Project 17-48 and 

supplemented with additional needs based on a 

review of the following sources: 

• CMF Most Wanted List (based on searches 

made on the CMF Clearinghouse Web site).

• Feedback from CMF Clearinghouse focus 

groups and webinars.

• Emails from CMF Clearinghouse users.

• Lists of experimental installations (Manual on 

Uniform Traffic Control Devices (MUTCD) and 

the National Association of City Transportation 

Officials).

• Countermeasures not evaluated in 

research studies (i.e., NCHRP 17-56 had 10 

countermeasures on their initial list but only 

sufficient budget to evaluate 4).

• States using CMFs that have little or no research 

backing (i.e., investigate State Web sites for 

their published list of CMFs used in the State).

• Past input and questions from practitioners 

(National Safety Engineers Listserv, AASHTO/

HSM online forum).

• International CMF-related research needs based 

on input from Pat Hassan. 

In the future, there is a need to consult ITE for a list of 

CMF needs. Ed Stollof presented a list of CMF needs 

based on input from ITE members.

The CMF research needs identified from these 

various sources were compiled into a database 

for comparison with the inventory of existing/

forthcoming CMFs. This step was necessary to 

identify and remove research needs that were 

already addressed or are being addressed through 

ongoing research. Table 2 illustrates the general 

structure for comparing identified CMF research 

needs with the existing/forthcoming CMFs. In this 

way, potential gaps were identified and carried 

forward for prioritization. The columns under 

“Perceived Need” identify the countermeasure 

category, specific countermeasures, and applicable 

scenario based on the identified research needs. 

The “Source” notes where the CMF research need 

was identified, and it is possible that multiple 

sources identified the same research need. The final 

set of columns under “Comparison to Resource 

Database” indicates whether existing/forthcoming 

CMFs are available to address the need. Note again 

the importance of proper details to define the specific CMF gap as indicated by the applicable crash 

type, crash severity, and area type. The star quality 

rating is also noted for reasons explained previously.

Prioritization of Research Needs 

The final step included a preliminary prioritization 

of research needs to identify high-priority countermeasure categories and individual countermeasures 

within the categories. A prioritization scheme was 
17

Table 1. Sources of research needs for NCHRP Project 17-48.

Source of Research Topics Mechanism for Extracting Topics

Research needs, as defined in Toward Zero Deaths: A 

National Strategy on Highway Safety.(4) Review of plan and review of topic-area white papers.

Knowledge gaps identified in the HSM.

At end of each chapter in part D of the HSM, there is a 

section on treatments where more research is needed. In 

addition, several CMFs in the HSM are not supported by 

details about their source studies such as exposure, target 

crash, site and roadway specification, and area type. These 

were also considered and developed for different scenarios 

of applications (e.g., two lane-rural roads and urban 

arterials). 

Knowledge gaps identified in work plan for 2nd edition 

of the HSM (NCHRP 20-07(279)) Contact Dr. Dan Turner, principal investigator. 

High-priority knowledge gaps identified in NCHRP 

Report 617, Accident Modification Factors for Traffic 

Engineering and ITS Improvements.(5)

Review of report. Note that this project included a survey 

of State transportation department safety engineers for 

research topic ideas. Responses were from 34 States. 

Research needs identified by States. Ballot results from previous ELCSI-PFS Technical Advisory 

Committee ballots. 

Research Problem Statements from key TRB 

Committees.

Problem statements from committees are located at 

http://rns.trb.org/. 

Unfunded high-priority NCHRP projects. Obtain from TRB staff (e.g., Mark Bush). 

Input from FHWA’s EAR Program.

Contact David Kuehn (david.kuehn@dot.gov), EAR 

program manager, and Kunik Lee (kunik.lee@dot.gov), EAR 

program coordinator in Safety R&D. 

Input from FHWA Office of Safety and Office of Safety 

R&D on unfunded needs.

Contact FHWA Safety R&D and FHWA Office of Safety for 

information and additional contacts. 

Input from FHWA Safety R&D ITS Safety Program on 

unfunded needs.

Contact Greg Davis (gregory.davis@dot.gov), ITS Safety 

Program Manager. 

Research topics identified in FHWA’s Pedestrian 

Strategic Safety Plan (draft).(6)

Obtain report from author (and 17-48 principal investigator) 

Charlie Zegeer. 

Topics identified by the National Highway Research and 

Technology Partnership.(7)

Review of Highway Research and Technology—The 

Need for Greater Investment (2002), including “Highway 

Infrastructure and Operations” section of appendix, 

available at http://onlinepubs.trb.org/onlinepubs/rtforum/

safety_agenda_july_2001.pdf. 

AAA-FTS’s Traffic Safety Issues of the Future: A Long 

Range Research Agenda, (2006).(8)

Review of report, available at http://www.aaafoundation.

org/pdf/FuturesReport.pdf. 

Knowledge gaps identified in Special Report 292 review 

of white papers.(9)

Review appendix B, Comments on Individual Projects 

Described in White Papers Commissioned by the Federal 

Highway Administration. 

Research needs identified in FHWA’s HSIS project for 

potential internal research (unpublished). Review listing prepared by HSIS project staff. 

SHRP2 prioritized listing of run-off-road and intersection 

research topics.

Review draft report: S02 Integration of Analysis Methods 

and Development of Analysis Plan. Phase 1 Report.(10)

Knowledge gaps identified by international research 

organizations.

Contact staff at institutes in Australia, Canada, France, 

Germany, Netherlands, New Zealand, Norway, Sweden, 

and the United Kingdom.

Contact staff at multinational sites—OECD, International 

Transport Forum/ Joint Transport Research Centre), World 

Health Organization, others. 

EAR = Exploratory Advanced Research.

OECD = Office of Economic Development.
18

developed based on how many sources identified 

a particular need and whether there is existing/

forthcoming information on the topic. The prioritization also considered the quality of existing CMFs. 

For example, a gap may be identified where the 

only available CMF is based on a simple before-after 

study with limited data. This type of gap, however, 

would be less of a priority than a gap in which there 

are no CMFs currently available. The preliminary prioritization scheme is represented by a simple tiered 

structure, arranging the research needs as follows:

• Research needs identified by multiple sources 

and have no existing/forthcoming CMFs.

• Research needs identified by multiple sources 

and have limited existing/forthcoming CMFs.

• Research needs identified by one source and 

have no existing/forthcoming CMFs.

• Research needs identified by one source and 

have limited existing/forthcoming CMFs.

• Research needs that have fairly complete or 

high quality existing/forthcoming CMFs.

The high-level results of the gap analysis and prioritization were shared with the participants during 

the CMF stakeholder meeting. The results were also 

shared with those involved with the international 

effort on the joint transferability of CMFs. 

Resources to Support DCMF Efforts

In addition to CMF-related research needs, it is important to understand the availability of resources to 

support CMF development efforts. As such, several 

safety databases were identified that could be used 

to help CMF stakeholders accomplish the following 

tasks:

• Identify and prioritize current CMF research 

needs (i.e., those already proposed).

• Identify, prioritize, and coordinate future CMF 

research that will yield more reliable CMFs 

and may be more cost-effective than current 

practices. The relevant questions for future 

research needs include the following:

• What resources are available and how can 

they be used?

• What parties can be involved?

• What tools are available and do better 

ones exist or can improvements be made 

to existing tools?

• What are the methodological needs and 

what efforts are needed or underway to 

meet those needs?

• Support and advance innovation in safety 

countermeasures to further reduce crash 

Table 2. General structure for identifying gaps.

Perceived Need Comparison to Resource Database

Category Countermeasure Applicable

Scenario Source

Existing/

Forthcoming

CMFs

Applicability

Star 

Rating

Crash

Type

 Crash

Severity

Area 

Type

Pedestrian

Rectangular 

rapid

flashing 

beacons

Urban and

Rural

CMF

Most

Wanted

List

Yes Unknown Unknown Unknown Unknown

Countdown

signals Urban

CMF

Most

Wanted

List

Yes Unknown Unknown Unknown Unknown
19

fatalities and severe injuries associated with 

prioritized safety needs.

• Identify current FHWA efforts and emerging 

statistical methodologies (e.g., those discussed 

at the recent Technical Experts Meeting for 

statisticians held under a separate DCMF task) 

that may support current needs, identify appropriate stakeholders that could be involved in 

promoting this effort, and determine priority 

research needs that have not been identified.

There are several existing databases to support the 

development of CMFs, but most provide crash-based 

data. The following databases were identified, under 

the DCMF task to identify CMF research needs, as relevant to supporting the four tasks listed previously:

• FARS.

• General Estimates System.

• Crashworthiness Data System.

• National Motor Vehicles Crash Causation Study 

(NMVCCS).

• Crash Injury Research and Engineering Network.

• Motor Carriers Management Information 

System.

• Federal Transit Administration National Transit 

Database.

• National Emergency Medical Services Information System.

• SHRP2 RID and NDS.

• National Park Service Service-wide Traffic 

Accident Reporting System.

• HSIS.

Table 6 through table 9 in appendix C provide a 

summary of these databases, including critical 

aspects of each database with respect to CMF 

development. Specifically, table 6 through table 9 in 

appendix C provide summary information such as 

the sponsoring agency, data coverage, data years, 

data availability, and database content. The last 

row of each table identifies the applicability to 

Tasks A–D. 

Advancing Highway Safety

The majority of the discussion during the CMF 

Stakeholder Meeting was focused on sharing current 

efforts in the interest of advancing highway safety. 

Specific discussions on advancing highway safety 

included research methods, technologies, and innovations. The following is a summary of the related 

presentations and discussion.

Current Predominant Methodologies for CMF 

Development

Study designs can be classified as experimental or 

observational studies based on cross-sectional or 

before-after data. In an experimental study, sites 

are identified for some treatment and randomly 

assigned to either a treatment or control group 

that is left untreated. The treatment and control 

groups are identified before implementation of the 

treatment. In an observational study, the treatment 

is implemented at some sites, not on the basis 

of a planned experiment but on engineering 

considerations, including safety. While experimental studies are common in other fields such as 

medicine, observational studies are more common 

in road safety research in view of the ethical 

concerns with experimentation in road safety.

For both experimental and observational studies, a 

before-after design is usually preferred to a crosssectional design. For the before-after design, the 

CMF is estimated from the change in crash frequency 

between the periods before and after the implementation of a treatment at a given site or group or sites. 

For the cross-sectional design, the CMF is estimated 

by comparing crash frequency across sites with 

different characteristics (i.e., with and without treatments). In either case, there is a need to account 

for changes in safety due to factors other than the 

treatment of interest.

There are several types of potential bias that may 

arise in before-after and cross-sectional studies. In a 

before-after study, it is necessary to account for other 

changes over time (e.g., changes in traffic volume, 

weather, demographics, and vehicle characteristics). 

It is also necessary to either dismiss or account for 

changes related to regression-to-the-mean, which 

is related to the random variation in crashes over 
20

time. In a cross-sectional study, it is necessary 

to account for differences among the sites with 

and without treatment. Potential biases related to 

before-after and cross-sectional studies are described in the NCHRP 20-7(314) Final Report, 

Recommended Protocols for Developing Crash 

Modification Factors.(11)

FHWA’s A Guide to Developing Quality CMFs further describes the variations of before-after and 

cross-sectional methods that are commonly used to 

develop CMFs.(1) Types of before-after studies include 

the simple, comparison group, and Empirical Bayes 

before-after methods. Cross-sectional methods 

include simple cross-tabulation and regressionbased modeling. The key takeaway is that not all 

methods are created equal, where some are better 

than others at accounting for potential biases. For 

example, the simple before-after method does not 

account for changes in traffic volume, regression-tothe-mean, or other temporal trends. In general, the 

Empirical Bayes (or Full Bayes) before-after method 

is the current gold standard for developing CMFs. 

Identifying Opportunities to Advance Current 

Methods 

The TRB Annual Meeting provides a forum for 

researchers and practitioners from all sectors (public, 

private, industry, and academia) to share their 

research needs and latest advancements. In total, 

there are 480 committees and panels with 4,600 committee members. Several standing committees work 

to advance the science of highway safety, including 

ANB10 (Transportation Safety Management), ANB20 

(Safety Data, Analysis, and Evaluation), and ANB25 

(Highway Safety Performance). Other committees 

support the advancement of the science of safety 

(e.g., ABJ80: Statistical Methods) although their 

primary mission is not focused on highway safety. 

These committees and their members work to 

identify research needs, conduct research, and 

disseminate research findings through the TRB 

annual and mid-year meetings. 

There is an opportunity to develop a compendium 

of TRB papers that focus on statistical methodologies applicable to highway safety evaluations under 

the DCMF program in the near future. In 2015, it is 

expected that more than 4,500 papers will be presented at the TRB Annual Meeting. These papers, 

some seemingly unrelated, represent incremental 

advances in the science of safety. Advances may 

include refinements to an existing process, testing 

of statistical distributions, and specific applications 

to data. The compendium of TRB papers on 

statistical methodologies for highway safety evaluations would identify and make recommendations 

for reliable and advanced methodologies, and 

highlight opportunities and areas of need so that 

CMF stakeholders, researchers, academics, and 

other interested parties can advance highway safety 

research. 

Advancing Methods in Transportation 

Statistics

The use of statistics has advanced in highway safety 

over the last 20 years. Methodologies have been 

borrowed from various statistical fields and adapted 

for use in highway safety analysis. Some methods 

have very specific and limited applications (e.g., 

Empirical Bayes before-after method) while others 

are applied more generally (e.g., tests of proportions 

and significance). While there have been substantial 

advancements in the science of safety, many of these 

methods have limitations in capability and applicability when used for highway safety research.

There is a need to develop new highway-specific 

statistical methodologies and to further tailor existing statistical methodologies to highway safety 

application. Specifically, there is an immediate need 

for methodologies to advance the development of 

CMFs, CMFunctions, and safety performance functions (SPF). Another short- to long-term need is to 

develop more statistical tools for effective use of 

available data resources.

Until recently, limited data have been a primary challenge in highway safety analysis. In response, FHWA 

and others have worked to improve data capabilities through guidance such as the Model Minimum 

Uniform Crash Criteria and the Model Inventory of 

Roadway Elements, as well as technical assistance 

efforts such as the crash data improvement 

program, roadway data improvement program, and 

the roadway safety data program. As data become 
21

more robust, reliable, and readily available, there 

will be a similar advancement in the development 

and improvement of analytical tools.

FHWA is making a concerted effort to enhance statistical methodologies for highway safety research. 

Roya Amjadi presented on the related FHWA efforts, 

including the assessment and use of statistical methodologies under the DCMF Program. As part of the 

DCMF Program, FHWA hosted a technical experts 

meeting of statisticians from various fields to help 

assess existing methods in highway safety analysis. 

FHWA is also working to sustain this effort through 

better coordination with ASA. The results of the 

technical experts meeting is documented in a 

separate white paper, Enhancing Statistical 

Methodologies for Highway Safety Research—

Impetus from FHWA.(12)

Tracking Technologies and New Strategies

The acceptance and implementation of a new strategy is not a trivial process. To accept a new strategy, 

practitioners must have sufficient knowledge of the 

strategy and confidence that it will result in a safety 

benefit (i.e., credible CMF). Practitioners must also 

have approval, funds, and expertise to implement a 

new strategy. The lifecycle of a strategy includes the 

following steps:

1. Early Development: In the early development 

phase, a concept or initial product is developed 

based on an expressed need or idea. This may 

result in simulator testing or closed environment 

deployment (i.e., test track). 

2. Introduction to Market: The introduction to 

market includes pilot field implementations, 

analysis of small-scale implementations based 

on safety surrogate measures (e.g., speed, lane 

keeping, road user opinion surveys), and anecdotal evidence (e.g., discussions with agencies 

to collect information on ease of implementation, treatment cost, durability, and level of 

effectiveness). The limited introduction to market 

helps to verify acceptance before deploying on a 

larger scale.

3. Evolution of Knowledge: The evolution 

of knowledge begins with the analysis of 

small-scale implementations when the strategy 

is introduced to the market. As a strategy gains 

acceptance, there may be additional implementations by the pilot agency with additional analysis

to update the previous results. Over time, implementations may spread to other agencies and 

provide an opportunity to evaluate the effectiveness under different conditions (e.g., urban/rural, 

different traffic volumes). Eventually, the goal 

is to conduct a statistically rigorous evaluation 

of the safety performance of the strategy based 

on multiple sites in multiple States/regions. The 

evolution of knowledge is satisfied when the 

safety performance is quantified with confidence.

4. Dissemination of Knowledge: The lifecycle 

does not end with evaluation. Instead, it is 

important to communicate the results of the 

evaluation so that others can use the information to improve future decisions.

The speed at which a strategy progresses through 

the lifecycle depends on a number of factors, including how well the strategy is tracked. For example, 

the early development depends on how well an idea 

or need is conveyed to those responsible for further 

developing those ideas. The introduction to market 

depends on how well the strategy performs in the 

pilot tests and how well the results of those tests are 

communicated. The evolution of knowledge depends 

on data from sites where the strategy is implemented, so it is critical for agencies to track where and 

when they implement safety improvements. 

To increase the speed at which a strategy progresses 

through the lifecycle, there is a need for increased 

information sharing throughout the process. 

Specifically, a method is needed to track new 

strategies and technologies as they are developed 

and deployed on the Nation’s roadways. The 

recommended process for tracking new strategies 

and technologies would include a single entity 

performing the search and maintaining a database, 

but in cooperation and coordination with other 

stakeholders. The leadership of a single entity will 

help avoid duplication of efforts. Table 3 presents 

a simplified layout for a recommended tracking 

mechanism. 
22

The recommended tracking mechanism would identify each new strategy or technology along with 

specific information related to the potential opportunity, implementation status, and current monitoring. 

The potential opportunity describes the intended 

use of the strategy (targeted safety issue). The implementation status helps define the point at which the 

strategy is in the lifecycle process (e.g., idea, concept, 

pilot, wide-scale deployment, or acceptance). 

Information related to current monitoring would 

help identify the level of evaluation and recent/

ongoing efforts to evaluate and disseminate the 

results.

Information on the current state of new strategies 

and technologies is held by somewhat disparate 

groups, including vendors, State and local practitioners, university researchers, private consultants, 

and several Federal agencies. A successful tracking 

process must access and assemble information from 

this wide range of sources. Again, it is recommended 

that a single entity lead the tracking effort with support from other stakeholders.

Potential venues or sources of information to populate the tracking database include the following:

• Trade shows and expositions at major conferences, including the American Traffic Safety 

Services Association (ATSSA) meeting, TRB 

annual meeting, and ITE annual meeting, 

among others. There is great potential for 

future coordination with ATSSA, and it may 

be possible to initiate conversations regarding a roundtable discussion at the ATSSA 2015 

annual meeting. ATSSA has an invited the Circle 

of Innovation portion to their annual meeting 

that may be appropriate.

• Listservs that are used by practitioners to 

discuss their experiences with safety strategies 

and technologies.

• FHWA Request to Experiment Database maintained by the FHWA MUTCD Team.

• Vendor product and technology marketing 

material made publicly available for marketing 

purposes.

• Annual Highway Safety Improvement Program 

(HSIP) reports. HSIP reports are submitted 

annually by each State to describe progress 

in implementing highway safety improvement projects, including project effectiveness. 

The reports include a general listing of projects, such as the improvement category/

subcategory, project output (e.g., miles of 

rumble strips), project cost (HSIP cost and total 

cost), funding category, roadway characteristics 

(e.g., functional classification, annual average

Table 3. Potential structure for tracking mechanism.

Strategy Potential Opportunity Implementation Status Current Monitoring

Strategy A

Strategy is designed 

to prevent run-off-road 

crashes.

Strategy implemented in one 

State (NC) at five sites.

NCDOT is conducting a beforeafter study of the impact of the 

strategy on speeds. Results 

expected in August 2014.

Strategy B

Strategy is designed to 

increase the visibility of 

pedestrians at midblock 

crossings.

Strategy was demonstrated 

at ATSSA meeting. It has not 

been installed in the United 

States.

Vendor has kept in 

communication with FHWA 

regarding U.S. installations.

Strategy C

Strategy is designed to 

increase the conspicuity 

of traffic signals.

Strategy is installed in five 

States (TX, NC, SC, PA, and 

MI), totaling 450 deployments.

Wayne State University is 

conducting a rigorous EB 

evaluation. Results expected in 

January 2015.

ATSSA = American Traffic Safety Services Association.

EB = Empirical Bayes.

NCDOT = North Carolina Department of Transportation.
23

daily traffic, and posted speed), roadway 

ownership, and relationship to the State’s strategic highway safety plan. Benefits include the 

collection of all HSIP projects in one location, 

and the States are required to report projects 

that have been funded. Potential challenges 

are that only HSIP projects are reported, projects are only associated with one improvement 

category, and improvement categories are not 

specific enough to identify specific strategies.

• Anecdotal information reported by States on 

their experiences and media requests.

• Research findings presented at conferences 

or published in leading journals. Because 

the tracking is focused on new technology, 

these findings would not include CMF 

research. Instead, the research of interest 

would include non-crash-based studies of 

the new technology, such as studies of the 

effect on operations (e.g., speed) and other 

surrogate measures (e.g., conflicts) through 

simulation, pilot demonstrations, or limited 

field implementation.

The tracking mechanism could be populated with 

the information from the following sources using 

one or more methods (e.g., having a single entity 

provide oversight and quality control of the database 

and employing crowdsourcing to help input strategies and using technical support contractors to track 

known strategies and implementations):

• DCMF Program: The selected project team 

would explore each of the potential sources 

to identify this information. For example, a 

member of the project team would attend one 

or more national trade shows (such as ATSSA) 

and actively pursue this information from the 

exhibit floor, visiting vendors to discuss their 

new strategies and technologies and collecting 

ancillary product material. The findings would 

be populated into the tracking mechanism and 

date stamped. This could be supplemented by 

reviews of publicly available vendor marketing 

materials such as Web sites and product 

brochures. Implementation information would 

be collected concurrently from practitioners 

by querying listservs or conducting surveys. 

The advantages of this method are that there 

is an existing contract mechanism in place, 

the task is related to the overall goals of the 

contract, and the contract team has extensive 

contacts in the community that would support 

this work. The disadvantage is that it might 

need to include a survey, which would require 

Office of Management and Budget approval. 

Additionally, the information collected would 

need to be maintained after the task and 

contract ended.

• FHWA or NCHPR Initiative: Similar to the 

DCMF method, another FHWA contract or 

NCHRP initiative could be used to collect 

the information using a similar method. The 

advantage of this approach is that there may be 

an opportunity to tie into other related efforts. 

The disadvantages are that it might require a 

new contract mechanism, a survey may also be 

needed, and, again, the information will need to 

be maintained after the contract ends. 

• Crowdsourcing: Crowdsourcing is the 

practice of obtaining needed services, ideas, 

or content by soliciting contributions from 

a large group of people (especially from an 

online community) rather than from traditional 

employees or suppliers. Using this method, 

an editable version of the tracking table would 

be posted in a publicly available location such 

as on a Wikipage or similar. The advantages 

of this method are that it casts the widest 

possible net and may be very inexpensive. 

The disadvantages are that the quality of the 

information may be lower and there is no 

incentive to populate the data.

Looking to the Future

Through the course of the CMF stakeholder meeting, there were several underlying themes around 

which the conversation revolved. Four specific 

themes were included: 1) CMF Opportunities, 2) Data 

and Methods, 3) Coordination and Training, and 

4) Innovation, Technology, and Other. The remainder of this section provides a summary of the discussion related to the four overarching themes, 

focusing on short- and long-term efforts to advance 

CMF developments. 
24

CMF Opportunities

The following is a summary of existing CMF efforts 

and future opportunities:

• Identifying CMF Needs: The CMF Needs 

Assessment and Gap Analysis identified and 

prioritized CMFs for future development. The 

primary needs were related to pedestrians, 

access management, alignment, bicyclists, 

intersection geometry, and on-street parking. 

The following are additional CMF needs and 

opportunities: 

• These needs were confirmed by Ed Stollof 

of ITE, who presented the CMF needs 

from the ITE community. Other highpriority CMF needs identified by the ITE 

community include CMFs for multi-modal, 

complete streets, and ITS/technologyrelated strategies. Beyond specific CMFs, 

there is a need to identify and consider the 

context in the CMF development process. 

For example, there could be CMFs for 

various land use and area types (e.g., 

urban central business district, low-density 

suburban, high-density suburban). It may 

be possible to get this information now if 

there is a concerted effort to promote the 

proper documentation of CMFs. There is 

an opportunity to incorporate advice from 

the ITE community in future CMF needs 

assessments and prioritization efforts.

• Topics of interest identified by the HSM 

community include speed, vulnerable 

users, and roadside hazards (trees). 

Behavioral countermeasures will also be 

included in the next edition of the HSM. 

There is a need for more comprehensive 

outreach to help with the prioritization 

of CMF research needs. Specifically, the 

AASHTO SCOHTS, Subcommittee on 

Traffic Engineering, and Subcommittee on 

Design would likely have input on CMF 

needs and priorities.

• There is the potential to incorporate CMF 

needs from FMCSA. FMCSA would like 

to develop a priority list of needs after 

seeing the list created under this effort, 

including the safety effects of a Smart 

Park truck parking tool (i.e., what is the 

safety risk associated with large trucks 

parked at the on/off ramps at rest areas or 

other highway locations?). In conjunction 

with the Smart Park initiative, another 

CMF could potentially be developed for 

crashes involving large, parked trucks 

and buses. More research is needed to 

determine the feasibility of this CMF, as 

well as coordination to identify potential 

partners and funding sources. 

• Disseminating CMF Needs: There were 

several sources of CMF needs identified 

in this paper. Beyond the identification and 

prioritization of CMF needs, there is a need to 

communicate the prioritized list to the CMF 

stakeholder community. There is an opportunity 

to post the results of the CMF Needs Assessment and Gap Analysis to the CMF 

Clearinghouse. This would help researchers 

and research sponsors as they allocate funding 

to various research programs and projects. A 

related effort is needed to communicate the 

status and details of ongoing CMF research to 

minimize duplication of efforts.

• Tracking Ongoing CMF Research: There is 

a need for researchers, research sponsors, and 

other CMF stakeholders to understand ongoing 

efforts with respect to advancing the science 

of CMFs. Better tracking and coordination of 

efforts will help minimize redundancies and 

duplication of effort, allowing funding to be 

spent to address other CMF needs. The TRB 

RiP database is an existing resource that could 

help with this issue. One limitation of the RiP 

database is that it relies on stakeholders to 

enter and update information on their respective studies. As such, the completeness and 

quality of the database is dependent on the 

participation and thoroughness of stakeholders.

• Improving CMF Research: The FHWA Office 

of Safety is currently working to improve the 

quality of CMFs by coordinating outreach 

efforts. In support of this effort, they are 

working to develop a draft outreach strategy 

as discussed previously. It will be important to 
25

target the potential audiences with the correct 

message. CMF research sponsors will need to be 

informed of the standardized RFP language and 

the advantages of including it in their scope of 

work. CMF developers will need to be aware of 

the various guidelines and training courses for 

developing CMFs. There may be an opportunity 

to change the layout and/or functionality of 

the Clearinghouse to raise awareness of the 

situational use of CMFs. Specifically, the user 

would be asked to identify the specific context 

of their scenario (e.g., area type, intersection 

type) to help convey the importance of context. 

• Relationship between Speed and Safety:

There is a need to incorporate or better 

account for speed in the development of 

CMFs. Specifically, there is the potential for 

some strategies to affect vehicle speeds either 

positively or negatively, which can affect the 

potential safety effectiveness. For example, 

traffic-calming measures are intended to 

reduce traffic speeds and volumes. As vehicle 

speeds are reduced, there is a potential safety 

benefit related to increased time for recovery, 

reduced stopping distances, and improved 

survivability (i.e., reduced risk of injury/fatality 

given a crash). In other cases, there is the 

potential for vehicle speeds to increase with 

the installation of certain strategies due to 

increased driver comfort and confidence. For 

example, repaving roadways and the installation of raised pavement markers would 

be expected to improve safety, but studies 

have shown safety disbenefits in some 

cases. There is a need to better quantify the 

relationship between speed and safety and 

how this relationship translates to the safety 

effectiveness of strategies that can affect speed.

• Combining Multiple CMFs: There is a need 

for a method to combine individual CMFs to 

better understand the safety effectiveness 

of multiple treatments. A current study is 

underway (NCHRP Project 17-63) to develop 

such a method, but further research may be 

necessary to fully understand or separate 

individual effects of multiple treatments.

• Transferability of CMFs: There is a need to 

better understand the transferability of CMFs 

within and among States. CMFs are developed 

for specific scenarios (e.g., urban, four-legged, 

signalized intersections). It is necessary to 

understand if the CMF value would change 

if the specific scenario changes. It is also necessary to understand if CMFs change among 

States where there are other notable differences in characteristics such as climate, terrain, 

driver populations, and overall safety culture 

(e.g., seatbelt laws, alcohol laws, and posted 

speeds). A related question that may deserve 

further exploration is the development and use 

of CMFs for different purposes (e.g., planning 

versus design). There is a current study underway (NCHRP Project 17-63) to better understand 

the transferability of CMFs, including the typical 

roadway characteristics and other factors that 

would affect transferability. One component 

of transferability is understanding the specific 

scenario under which the CMF was developed. 

As such, proper documentation is a critical 

first step toward understanding transferability. 

Guidance on the proper documentation of CMF 

development efforts is provided in the NCHRP 

report Recommended Protocols for Developing 

CMFs.(11) Further effort is needed to promote 

the use of that guidance.

Data and Methods

The following is a summary of issues and opportunities related to data and methods used in the development of CMFs:

• Quality Data: There is a need for new sources 

of data and more complete and higher-quality 

data across the board, including better data 

for local roads and better tracking of safety 

improvements. The quality of CMFs and 

potential to develop more advanced 

statistical methods depends on the quality 

and completeness of the underlying data. 

Many of the CMF stakeholders confirmed the 

need for data, including FMCSA, which uses 

microdata (i.e., detailed information about 

drivers, vehicles, and companies) to support 

day-to-day operational decision-making. 

William Bannister of FMCSA noted that 
26

high-quality data are necessary to ensure the 

correct identification of motor carriers and 

drivers who present the greatest safety risk. 

The same can be said with respect to the 

identification of road segments, curves, and 

intersections.

• Supplemental and Emerging Databases:

Several data resources were identified and summarized as part of this effort (see appendix C). 

Additional databases and potential resources 

were identified during the CMF stakeholder 

meeting, including the SHRP2 data and FMCSA 

databases (i.e., SMS and A&I online), which 

were described previously. Other potential 

databases include the following:

• Large Truck Crash Causation Study:

This study was the predecessor to 

NMVCCS, and there is the potential for 

an update to these databases in the near 

future.

• NHTSA’s State Data System (SDS):

SDS is maintained by NHTSA’s National 

Center for Statistics and Analysis. There 

are currently 32 States providing electronic 

crash data files to NHTSA for SDS. The 

objective of SDS is to fully develop the 

analytic potential of all State data of 

relevance to highway safety. A potential 

limitation of this dataset is that there is 

no quality control; SDS is based on data 

reported directly from the States.

• Nationwide Inpatient Sample (NIS): 

The NIS database is part of a family of 

databases and software tools developed 

for the Healthcare Cost and Utilization 

Project (HCUP). NIS is the largest all-payer 

inpatient health care database in the 

United States, yielding national estimates 

of hospital inpatient stays. Sampled from 

the State Inpatient Databases, HCUP’s NIS 

contains all discharge data from more 

than 1,000 short-term and non-Federal 

hospitals each year, which approximates 

a 20 percent stratified sample of U.S. 

community hospitals. It contains data from 

approximately 8 million hospital stays 

each year. Specific data include charge 

information on all patients, including 

individuals covered by Medicare, 

Medicaid, or private insurance, as well 

as those who are uninsured. These data 

can be used to identify, track, and analyze 

national trends in health care utilization, 

access, charges, quality, and outcomes.

• National Trauma Data Bank (NTDB): 

NTDB is the largest aggregation of trauma 

registry data ever assembled. The data may 

be obtained and used for informational 

and research purposes with approval 

from the American College of Surgeons 

Committee on Trauma. The goal of NTDB 

is to inform the medical community, the 

public, and decisionmakers about issues 

that characterize the current state of care 

for injured persons. Additional information 

is available at http://www.facs.org/trauma/

ntdb/index.html.

• IIHS: There is the potential to use 

insurance data to obtain information such 

as exposure by various groups.

• Assessment Methods: There are various 

methods to assess and evaluate the safety 

performance of a roadway facility, vehicle, or 

driver. Some methods are site-specific while 

others are more systemic. Some methods are 

crash-based and rely on the crash history from 

specific sites to help estimate future safety 

performance. Others are risk-based and rely 

on the site characteristics to estimate potential 

crash risk. There is value to all of these methods, 

and they are not mutually exclusive. In some 

cases, an agency may combine output from all 

of the methods to develop a safety program. 

In other cases, an agency may be confined 

to specific methods based on the availability 

of data. The following is a brief summary of 

some of the methods discussed during the CMF 

Stakeholder Meeting:

• usRAP: One of the objectives of this 

program is to promote the assessment of 

risk as a major part of strategic decisions 

on roadway improvements. One aspect 
27

of the program is crash-based, while 

the other is risk-based. The crash-based 

component uses crash data to develop 

risk maps, which can be used to document 

the risk of fatal and serious injury crashes 

and show where risk is high and low. 

The risk-based component uses roadway 

characteristics to determine star ratings 

and examine how well they protect users 

from crashes and from deaths and serious 

injuries when crashes occur.

• FMCSA Risk Models: FMCSA develops 

models to assist in various aspects of 

their safety program. For example, they 

develop algorithms to relate risk factors 

(e.g., hours of service, vehicle type) to 

crash risks. These models are essentially 

SPFs that can be used to identify highrisk drivers and carriers. FMCSA is also 

developing models to assess the benefits 

of their programs and determine the 

success of their interventions, similar to 

CMFs.

• Systemic Safety Analysis: FHWA has 

developed the Systemic Safety Project 

Selection Tool, but there is an opportunity to 

further advance the state of the practice in 

systemic safety analysis. One opportunity 

is to identify States that are currently 

implementing systemic treatments to fasttrack the evaluation of those treatments 

and dissemination of results. (Note that 

Louisiana is implementing systemic 

treatments and would be happy to share 

data.) Another opportunity is to apply 

the systemic approach to support the 

FHWA Focused Approach to Safety. The 

objective would be to conduct an analysis 

of nationally representative data and 

provide the results to the FHWA focus 

States to support their safety efforts. 

The analysis would help State and local 

agencies better understand how risk 

factors relate to specific crash types and 

how these relationships may differ across 

various facility types. One product of this 

effort could be a matrix of risk factors 

by focus group (i.e., roadway departure, 

intersections, and pedestrians) by facility 

type (e.g., 2-lane rural, multilane rural, 

urban/suburban arterial). 

• Value of Advanced Methods: There is a need 

to promote the use of scientifically rigorous 

methods by demonstrating the value of these 

methods compared to traditional methods. 

There is a current effort underway through the 

FHWA Office of Safety to develop a Safety Data 

and Analysis Toolbox. As part of this effort, 

select new tools will be developed, including 

a tool (i.e., guide) to articulate and hopefully 

demonstrate the value of rigorous methods 

throughout the safety management process 

(from network screening to project evaluation).

Communication and Coordination

There is a need to enhance communication and 

coordination among CMF stakeholders. In general, 

the message and content should be appropriate 

for the target audience. For example, decisionmakers are not likely to read a research report. Instead, 

TechBriefs are appropriate to inform decisionmakers and communities of the safety effects of new 

and innovative strategies. The following is a list of 

potential opportunities to enhance communication 

and coordination of CMF-related efforts through new 

and existing mechanisms:

• CMF Clearinghouse: The CMF Clearinghouse 

is one opportunity to facilitate enhanced communication. Currently, the CMF Clearinghouse 

is the go-to resource for CMFs and CMF-related 

resources. As such, it might be a natural choice 

for providing information related to CMF 

needs, ongoing CMF research, and a forum for 

collecting CMF-related research needs (in 

addition to the Most Wanted List). As identified 

by Ed Stollof from ITE, users will want to 

obtain the majority of CMF information from a 

single source; they will not click multiple links 

to search multiple sites.

• RiP Database: There is the potential to utilize 

the existing TRB RiP database to track ongoing 

research. A benefit of this option is that the 
28

database is already established. A potential 

limitation is that the database is underutilized, 

and it may continue to be underutilized unless 

there is an effort to improve the functionality 

or increase awareness to encourage consistent use.

• TRB Annual and Midyear Meetings: TRB 

committee meetings, particularly ANB20 and 

ANB25, provide an opportunity to advance 

CMF-related research needs as well as ideas 

developed in the CMF Stakeholder Meeting. 

In general, TRB is an opportunity to coordinate 

research surrounding a given topic. For 

example, roundabouts are a cross-cutting issue 

that could touch safety, operations, design, 

pedestrians, and bicyclists. TRB hosts regular 

meetings, workshops, and webinars to allow 

communities to communicate and coordinate.

• SHRP2: There is an opportunity to communicate the list of CMF needs and priorities on the 

SHRP2 Web site. Researchers could then use 

the SHRP2 data to address the pressing needs. 

These data may also provide an opportunity for 

students looking for research topics for their 

thesis or dissertation. There is also a potential 

to list or identify common pitfalls and potential 

issues related to the use of the SHRP2 data, 

which will allow users to learn from others’ past 

experiences and help advance the methods 

and analysis.

• ITE: ITE could serve as a forum or distribution 

network at the grass roots level because 

their membership includes all levels of CMF 

stakeholders and users.

• AASHTO Innovation Initiative (former 

TIG): This initiative designates “champions” 

to promote technologies, which can then 

be implemented and evaluated. It will be 

important for the CMF community at large to 

understand which technologies the AASHTO 

group is promoting. It will also be important 

for the AASHTO group to understand the 

safety effectiveness (i.e., CMFs) related to the 

technologies they are promoting. The AASHTO 

group could also establish a formal link with 

other similar efforts such as the FHWA EDC 

initiative, FHWA Proven Countermeasures, 

and the ATSSA Circle of Innovation. Currently, 

FHWA develops a list of technologies that 

could/should be accelerated and sends the list 

to AASHTO asking for feedback on priorities. 

• Review of Research: Despite the development of several guides related to development 

of CMFs (e.g., FHWA’s A Guide to Developing 

Quality CMFs and NCHRP’s Recommended 

Protocols for Developing CMFs), the quality 

of CMFs continues to be an issue. One challenge to improving the quality of CMFs is the 

need to inform all CMF research sponsors and 

developers. This report has outlined several 

different CMF development efforts and funding agencies. The next step is to promote the 

use of existing guides to improve the quality 

of CMFs. There is also the potential to establish 

a mechanism to cross-examine CMF-related 

research. For example, IIHS is planning to conduct a study on the safety effects of changes 

in speed limits. Other CMF stakeholders may 

have suggestions on factors to consider during 

the research, but there is not currently a forum 

or mechanism to provide that feedback. There 

may be an opportunity to investigate how the 

CMF stakeholder community can help guide 

research from both a needs perspective and an 

existing knowledge perspective.

Training

There were several training-related needs and 

opportunities identified during the CMF Stakeholder 

Meeting. The primary concern was that CMFs are 

crucial components of the decisionmaking process, 

but there is still a lack of understanding and proper 

use of CMFs, particularly at the local level. Training 

opportunities include:

• Promotion: There is the potential to increase 

attendance in existing CMF-related courses by 

better promoting these events and opening the 

training to all safety stakeholders rather than 

focusing on States (if this is in fact the current 

practice). One hook to promote training is with 

professional development hours.

• Expansion: There is a need to integrate 

transportation-specific exercises and 
29

assignments in existing statistics courses. 

Universities across the country offer both 

transportation and statistics courses, which 

present opportunities to cross-educate transportation engineers and statisticians.

• Refreshers: Training is not a “one-and-done” 

exercise; it is an ongoing process. As the 

science and practice of CMFs develop, it will be 

important to convey any changes to the CMF 

community, particularly those that have already 

been trained. There is a need to reinforce old 

concepts and identify recent developments. For 

some users, it will be necessary to understand 

the statistics and methodologies, but for most, 

it will be sufficient to understand the selection 

and appropriate use of CMFs.

There were also several potential training-related 

challenges identified during the meeting. The primary challenge is that CMF users come from all 

strata, from the local level practitioner to consultants 

to the Federal government. In this regard, not all 

individuals have the same technical or time capacity to understand and apply CMFs. In some cases, 

users may be tempted to rely solely on the CMF 

Clearinghouse as a quick reference tool because of 

resources, immediate responses needed for investment, and other decisions or other factors. It is 

important for CMF stakeholders to understand that 

CMFs are just one component of a quantitative 

safety management process.

Innovation, Technology, and Other

The following programs and tools will be useful for 

individuals developing CMFs:

• usRAP and International Road Assessment 

Program (iRAP): The new version of usRAP 

(version 3.0) is about to be released. This version 

will include a video tool for data coding. iRAP 

has also released information on the underlying 

methods and risk factors incorporated in the 

tool. This information is available at http://www.

irap.net/en/about-irap-3/methodology. There is 

the potential to link to usRAP and iRAP from the 

CMF Clearinghouse. The common link between 

the CMF Clearinghouse and usRAP is the section 

on risk factors. While usRAP is more complex 

than the CMF Clearinghouse, it would position 

agencies for longer-term investment decisions. 

It also includes a method for assessing risk to 

pedestrians and bicyclists, which is not wellcovered in other tools.

• FMCSA Tools and Technology: FMCSA has 

continued to innovate in the name of safety by 

developing the following tools and technology: 

• Smart Infrared Inspection System 

(SIRIS): FMCSA launched a project to 

demonstrate SIRIS, which uses state-of-theart thermal imagery technology, integrated 

with signature recognition software, to 

identify faults and impending failures in 

tires, brakes, and bearings mounted on 

large trucks and motor coaches and to alert 

roadside inspectors in real time. 

• Wireless Roadside Inspections: FMCSA 

is testing a wireless roadside inspection 

system that will automatically gather 

information about trucks, drivers, and 

carriers without stopping vehicles. The 

goal is to use commercial mobile radio 

service technology to conduct inspections 

as trucks travel along the highway. 

• Bus Safety App: FMCSA has developed 

the Saferbus mobile app to help 

consumers identify the risk and track 

record of a carrier. This app could be used 

by insurance companies or the general 

public.

• AASHTO Innovation Initiative: This 

initiative is a systematic approach for moving 

new technology into day-to-day practice. 

Opportunities to track and coordinate efforts 

were discussed previously in this report.

• Strategy Tracking: There is a need for better 

mechanisms to track strategies from concept 

to CMF. A potential framework for a tracking 

mechanism was described in this report, 

but further research is needed to refine and 

populate such a tool. 
30

State Contact Organization Email 

Alabama

Timothy Barnett Alabama Department of 

Transportation barnettt@dot.state.al.us

Linda Guin FHWA Alabama Division linda.guin@dot.gov

Sonya Baker Alabama Department of 

Transportation bakers@dot.state.al.us

Arizona Kohinoor Kar Arizona Department of 

Transportation kkar@azdot.gov

Arkansas Adnan Qazi Arkansas State Highway and 

Transportation Department adnan.oazi@ahtd.ar.gov

California Thomas Schriber California Department of 

Transportation thomas.schriber@dot.ca.gov

Colorado

Alisa Babler

Colorado Department of 

Transportation

alisa.babler@state.co.us

Charles Meyer charles.e.meyer@state.co.us

David Swenka david.swenka@state.co.us

Connecticut Joe Ouellette Connecticut Department of 

Transportation joseph.ouellette@ct.gov

Florida Joe Santos Florida Department of 

Transportation joseph.santos@dot.state.fl.us

Georgia Michael Turpeau Georgia Department of 

Transportation mturpeau@dot.ga.gov

llinois

Priscilla Tobias

Strategy A Illinois 

Department of Transportation

priscilla.tobias@illinois.gov

Tim Sheehan

tim.sheehan@Illinois.gov

Riyad Wahab riyad.wahab@illinois.gov

Indiana Mike Holowaty Indiana Department of 

Transportation mholowaty@indot.in.gov

Iowa Jan Laaser-Webb Iowa Department of 

Transportation

jan.laaser-webb@dot.iowa.

gov

Kansas Steven Buckley Kansas Department of 

Transportation buckley@ksdot.org

Kentucky Tracy Lovell Kentucky Transportation 

Cabinet tracy.lovell@ky.gov

Louisiana April Renard

Louisiana Department 

of Transportation and 

Development

april.renard@la.gov

Maryland

Eric Tabacek Maryland State Highway 

Administration

etabacek@sha.state.md.us

Ruihua Tao rtao@sha.state.md.us

Massachusetts Lisa Schletzbaum Massachusetts Highway 

Department

lisa.schletzbaum@state.

ma.us

Michigan Mark Bott Michigan Department of 

Transportation bottm@michigan.gov

Minnesota Brad Estochen Minnesota Department of 

Transportation bradley.estochen@state.mn.us

Mississippi

Daniel Helms Traffic Engineering Division, 

Mississippi Department of 

Transportation

dhelms@mdot.ms.gov

Mark Thomas mthomas@mdot.ms.gov

Table 4. State transportation department and partner members of ELCSI-PFS.

Appendix A: CMF Stakeholders
31

State Contact Organization Email 

Missouri John Miller Missouri Department of 

Transportation john.p.miller@modot.mo.gov

Montana Kraig McLeod Montana Department of 

Transportation krmcleod@mt.gov

Nevada

PD Kiser Nevada Department of 

Transportation

pkiser@dot.state.nv.us

Ken Mammen kmammen@dot.state.nv.us

New Hampshire

Michelle Marshall

New Hampshire Department 

of Transportation

memarshall@dot.state.nh.us

Ron Grandmaison rgrandmaison@dot.state.

nh.us

New York Rob Limoges New York State Department 

of Transportation rlimoges@dot.ny.gov

North Carolina

Brian Mayhew North Carolina Department 

of Transportation

bmayhew@ncdot.gov

Shawn Troy stroy@ncdot.gov

North Dakota Shawn Kuntz 

Planning & Programming 

Division, North Dakota 

Department of Transportation

skuntz@nd.gov

Oklahoma David Glabas Oklahoma Department of 

Transportation dglabas@odot.org

Ohio Michael McNeill Ohio Department of 

Transportation

michael.mcneill@dot.state.

oh.us

Pennsylvania

Gary Modi Bureau of Highway Safety 

and Traffic Engineering, 

Pennsylvania Department of 

Transportation 

gmodi@pa.gov

Chris Speese chspeese@pa.gov

Jeff Roecker jroecker@pa.govc

Rhode Island

Bob Rocchio

Rhode Island Department of 

Transportation

brocchio@dot.ri.gov

Sean Raymond sean.raymond@dot.ri.gov

Jeffry Martins jmartins@dot.ri.gov

South Dakota Michael Behm South Dakota Department of 

Transportation michael.behm@state.sd.us

Tennessee Brian Hurst Tennessee Department of 

Transportation brian.hurst@tn.gov

Texas Brian Stanford Traffic Operations, Texas 

Department of Transportation bstanfo@dot.state.tx.us

Utah

Robert Hull Utah Department of 

Transportation

rhull@utah.govs

Scott Jones wsjones@utah.gov

Virginia Stephen Read Virginia Department of 

Transportation HSIP Manager 

stephen.read@vdot.virginia.

gov

Washington

John Milton Washington State 

Department of Transportation

miltonj@wsdot.wa.gov

Jennene Ring ringj@wsdot.wa.gov

 Wisconsin

John Bridwell Wisconsin Department of 

Transportation

john.bridwell@dot.wi.gov

Brian Porter brian.porter@dot.wi.govv

University of WisconsinAndrea Bill Madison bill@wisc.edu

Table 4. State transportation department and partner members of ELCSI-PFS (continued).
32

Agency Contact Email/Phone

FHWA Office of Safety Research and 

Development

Roya Amjadi roya.amjadi@dot.gov 

202-493-3383

Monique Evans monique.evans@dot.gov

202-493-3074

James Pol james.pol@dot.gov

FHWA Office of Safety

Karen Scurry karen.scurry@dot.gov

609-637-4207 

Ray Krammes ray.krammes@dot.gov

Cathy Satterfield cathy.satterfield@dot.gov

708-283-3552

Brian Fouch brian.fouch@dot.gov

Joseph Cheung joseph.cheung@dot.gov

FHWA Resource Center

Pat Hasson patrick.hasson@dot.gov

708-283-3595 

Andy Mergenmeier andy.mergenmeier@dot.gov

Frank Julian frank.julian@dot.gov

Gene Amparano gene.amparano@dot.gov

FHWA Office of Safety Field

Kelly Larosa (AZ Division) kelly.larosa@dot.gov

Ken Kochevar (CA Division)

Arianna Valle (CA Division)

ken.kochevar@dot.gov 

arianna.valle@dot.gov

FHWA Office of Infrastructure Michael Matzke michael.matzke@dot.gov

FHWA Office of Infrastructure R&D Katherine Petros katherine.petros@dot.gov

FHWA Office of Operation Jimmy Chu jimmy.chu@dot.gov

FHWA Office of Freight Management Caitlin Rayman caitlin.rayman@dot.gov

NHTSA

Kristie Johnsonw kristie.johnson@dot.gov

202-366-2755

Heidi Coleman heidi.coleman@dot.gov

202-366-2568

Richard Compton richard.compton@dot.gov

202-366-2699

GHSA Jonathan Adkins jadkins@ghsa.org

ITS JPO

Kate Hartman kate.hartman@dot.gov

Kevin Dopart kevin.dopart@dot.gov

Mike Pina michael.pina@dot.gov

Table 5. USDOT and partner agency contacts.
33

Agency Contact Email/Phone

FMCSA

Martin Walker martin.walker@dot.gov

William Bannister william.bannister@dot.gov

AASHTO Kelly Hardy khardy@aashto.org 

202-624-5868

NCHRP Mark Bush mbush@nas.edu

TRB Bernardo Kleiner bkleiner@nas.edu

TRB Transportation Safety 

Management Committee (ANB10)

Frank Gross (Research Coor.)

Robert Hull (Co-Chair)

Jake Kononov (Co-Chair)

fgross@vhb.com

TRB Safety Data, Analysis, and 

Evaluation Committee (ANB20)

Kim Eccles (Secretary) 

Bhagwant Persaud (Co-Chair)

Chris Monsere (Co-Chair)

keccles@vhb.com

TRB Highway Safety Workforce 

Development Committee (ANB23)

Frank Gross (Research Coor.) 

Barbara Harsha (Co-Chair)

Terecia Wilson (Co-Chair)

fgross@vhb.com

TRB Highway Safety Performance 

Committee (ANB25) John Milton miltonj@wsdot.wa.gov

SHRP2 David Plazak dplazak@nas.edu

TCRP Dianne Schwager dschwage@nas.edu

202-334-2969

AAA-FTS Peter Kissinger pkissinger@aaafoundation.org

202-638-5944

ATSSA Roger Wentz roger.wentz@atssa.com

800-272-8772 x 120

RSF Greg Cohen info@roadwaysafety.org

CVSA Collin Mooney collinm@cvsa.org

301-830-6149 

IIHS Anne McCartt amccartt@iihs.org

703-247-1534

ITE Douglas Noble dnoble@ite.org

202-785-0060 x 148

ENTERPRISE

Bill Legg kleggb@wsdot.wa.gov

360-705-7994

Ginny Crowsont crowson@acconsultants.org

651-600-3338

Table 5. USDOT and partner agency contacts (continued).

CVSA = Commercial Vehicle Safety Alliance.

GHSA = Governors Highway Safety Association.

JPO = Joint Program Office.
34

USDOT and Partner Agencies

CMF researchers and developers include individuals from the following key partnering agencies and 

bodies:

• FHWA.

• Office of Safety.

• Office of Safety Research, Development, 

and Technology.

• Other FHWA Offices (e.g., Operations).

• Resource Center.

• Division Offices.

• NHTSA.

• Governors Highway Safety Association.

• Research and Innovative Technology Administration.

• ITS Joint Program Office.

• FMCSA.

• AASHTO.

• SCOHTS.

• SCOSM.

• TRB (e.g., representatives from related TRB 

committees and NCHRP senior program 

officers).

• ANB10–Transportation Safety Management.

• ANB20–Safety Data, Analysis, and Evaluation.

• ANB23–Highway Safety Workforce Development.

• ANB25–Highway Safety Performance.

• NCHRP.

• TCRP.

• SHRP2.

• AAA-FTS.

• TSSA.

• IIHS.

• ITE.

• Commercial Vehicle Safety Alliance.

• Other pooled fund studies (e.g., ENTERPRISE, 

Traffic Control Devices, All Roads Network Of 

Linear-referenced Data).

The contacts from each group are listed in table 5.
35

Appendix B: CMF Stakeholder Meeting 

Agenda

• 9:00 AM: Welcome, FHWA, Monique Evans and 

Patrick Hasson.

• Introductions.

• Meeting objectives and overview of 

agenda.

• Brief introduction to CMFs—application, 

market, and demand.

• 9:30 AM: USDOT Partners CMF-Related Efforts 

and Perspectives

• FHWA Office of Safety R&D, Roya Amjadi.

• FHWA Office of Safety, Karen Scurry.

• FHWA Resource Center, Patrick Hasson.

• FMCSA, William Bannister.

• NHTSA, Kristie Johnson (remote).

• Other USDOT efforts.

• 10:30 AM: Break. 

• 10:45 AM: Partner CMF-Related Efforts and 

Opportunities. 

• Partner presentations. 

• AAA-FTS, Doug Hardwood, MRI Global.

• AASHTO, Kelly Hardy.

° SCOHTS and SCOSM.

° HSM Efforts.

• IIHS, Wen Hu.

• ITE, Ed Stollof.

• NAS, Bernardo Kleiner and David 

Plazak.

• TRB.

° ANB20 Safety Data, Analysis, and 

Evaluation Committee.

° ANB25 Highway Safety Performance 

Committee.

• NCHRP.

• SHRP2.

• International efforts.

• State transportation department efforts.

• Other partners and related efforts.

• Partner discussion.

• 12:00 PM: Lunch. 

• 1:00 PM: Partner CMF-related efforts and 

opportunities (cont’d).

• 2:00 PM: CMF Gap Analysis and Research 

Needs, Frank Gross (VHB) and Daniel Carter 

(North Carolina Highway Safety Research Center).

• Summary of gap analysis and ongoing 

research.

• Summary of identified CMF research needs.

• Partner discussion. 

• 2:45 PM: Break.

• 3:00 PM: Advancing Highway Safety—Research 

Methods, Technologies, Innovation.

• Research methods.

• Overview of current predominant 

methodologies, Frank Gross (VHB).

• Compendium of TRB papers for statistical methodologies applicable to highway 

safety evaluations, Kim Eccles (VHB).

• Transportation Statistics, Roya Amjadi 

(FHWA).

° FHWA Technical Experts Mtg—white 

paper and marketing. 

° Coordination with ASA.

• Methodologies, Technologies, and 

Innovation.

° Tracking technologies and new strategies, Kim Eccles (VHB) and Karen Scurry.

° FHWA database focus State 

approach to systemic safety,

Karen Scurry.

• Partner discussion. 

• 4:00 PM: Looking to the Future, Pat Hasson.

• Future Needs for Advancing CMF 

Development.

• Communicating and Coordinating Efforts.

• Others.

• 4:30 PM: Wrap-up and Next Step.
36

FARS GES CDS NMVCCS

Who houses and maintains 

the data?

NASS; directed by NCSA, which is a component 

of Policy and Operations in NHTSA.

NASS; directed by NCSA, a component of Policy 

and Operations in NHTSA.

NASS; directed by NCSA, a component of Policy 

and Operations in NHTSA.

NASS; directed by NCSA, a component of Policy 

and Operations in NHTSA.

What is the spatial coverage of 

the data?

All qualifying fatal crashes within the 50 States, 

the District of Columbia, and Puerto Rico.

Obtained from 60 geographic sites that reflect the 

geography, roadway mileage, population, and 

traffic density of the United States; approximately 

400 police jurisdictions included in the sampling.

Obtained from 24 geographic sites that reflect the 

geography, roadway mileage, population, and 

traffic density of the United States.

Sample of crashes in 24 PSUs, centered on large 

cities/counties/metro areas; include cities and 

counties in AL, AZ, CA, CO, FL, IL, IN, MD, MI, NE, 

NJ, NY, NC, PA, TN, TX, WA.

What years of data are in the 

database? 1975 to 2012 1988 to 2012 1979 to 2012 January 2005 to December 2007

What is the general availability 

of the data? FTP site: ftp://ftp.nhtsa.dot.gov/fars/ FTP site: ftp://ftp.nhtsa.dot.gov/GES/ FTP site: ftp://ftp.nhtsa.dot.gov/NASS/ FTP site: ftp://ftp.nhtsa.dot.gov/NASS/NMVCCS/

How are the data collected? 

How are the data coded?

Cooperative agreement with agency in each State 

to provide information in standard format on 

fatal crashes in the State; data collected, coded 

and submitted into database. The data are coded 

for:

• Crash variables.

• Vehicle variables.

• Person variables.

Data collectors make weekly, biweekly, or 

monthly visits to selected police agencies, and 

randomly sample about 50,000 PARs each year; 

approximately 90 data elements; for privacy 

reasons, no personal information nor specific 

crash location is coded.

24 research teams at PSUs study between 3,000 

and 5,000 crashes a year involving passenger 

cars, light trucks, vans, and utility vehicles; 

investigators obtain data from selected police 

agencies, crash sites, and study all available 

evidence; interview crash victims and review 

medical records; more than 600 elements coded; 

for privacy reasons, no personal information nor 

specific crash location is coded.

Investigated crash locations while first 

responders were still on-site; reconstruct crash 

by collecting all available data and interviewing 

witnesses; identify critical pre-crash event, critical 

reason for crash event, and other associated 

factors; over 500 elements coded.

Does the database include all 

crashes for the coverage area 

(i.e., the population) or just a 

portion of the crashes (i.e., a 

sample)?

Includes population of crashes with fatal 

outcome; fatalities are defined as a death to an 

individual occurring within 30 days of a crash 

due to injuries sustained in the crash.

Includes only portion of crashes, sampled 

randomly from 60 geographic sites and some 

400 police agencies across the United States.

Includes only portion of crashes, sampled 

randomly from 24 geographic sites across the 

United States.

Sample of crashes from each PSU.

How are crash severity levels 

defined? KABCO KABCO KABCO and sometimes Abbreviated Injury Scale

KABCO, plus:

• Died prior to crash

• Unknown if injured

What is the vehicle type 

coverage? All vehicle types. All vehicle types. Crashes involving at least one light vehicle < 10,000 lbs.

Crashes involving at least one light vehicle 

< 10,000 lbs.

If data is just a sample, how 

was the sampling done? NA

(1) Selection of primary sampling units (PSUs).

(2) Selection of police jurisdictions.

(3) Selection of crashes.

(1) Selection of primary sampling units (PSUs).

(2) Selection of police jurisdictions.

(3) Selection of crashes.

Six-hour sampling time period (between 6AM 

and midnight) selected each week; then divided 

into sampling days with tendency to maximize 

probability of observing crash during selected 

sampling periods.

If just a sample, what (if 

any) guidance is given to 

incorporate the sampling 

procedure into data analysis?

NA

A national weight has been added to the file for 

each PAR and is called “WEIGHT.” This weight 

is the product of the inverse of the probabilities 

of selection at each of the three stages in the 

sampling process.

Data are weighted to represent all police reported 

motor vehicle crashes occurring in the United 

States during the year involving passenger cars, 

light trucks and vans that were towed due to 

damage.

A comprehensive weighting procedure, 

that makes the NMVCCS sample nationally 

representative, consists of mainly two 

phases, the design weight and its appropriate 

adjustment.

Table 6. Resource databases to support DCMF efforts (FARS, GES, CDS, NMVCCS).

Appendix C: Resource Databases to Support DCMF Efforts
37

FARS GES CDS NMVCCS

To which Tasks (A–D) is the 

database applicable?

A: Prioritize current CMF research needs based 

on magnitude of fatalities.

B: Prioritize future CMF research based on 

magnitude of fatalities.

C: Support and advance innovation in safety 

countermeasures by demonstrating the 

magnitude of related fatalities.

D: Determine priority research needs that have 

not been identified based on magnitude of 

fatalities and related factors.

A: Prioritize current CMF research needs based 

on magnitude and severity of crashes.

B: Prioritize future CMF research based on 

magnitude and severity of crashes.

C: Support and advance innovation in safety 

countermeasures by demonstrating the 

magnitude and severity of related crashes.

D: Determine priority research needs that have 

not been identified based on magnitude and 

severity of crashes and related factors.

C: Support and advance innovation in safety 

countermeasures by identifying the underlying 

crash contributing factors related to light 

vehicle crashes.

D: Determine priority research needs that have 

not been identified based on the investigation 

of crash contributing factors.

C: Support and advance innovation in safety 

countermeasures by identifying the underlying 

crash contributing factors related to light 

vehicle crashes.

D: Determine priority research needs that have 

not been identified based on the investigation 

of crash contributing factors.

CDS = Crashworthiness Data System.

FTP = File Transfer Protocol.

GES = General Estimates System.

KABCO = KABCO injury severity scale, where K = killed, A = incapacitating injury, B = non-incapacitating injury, C = possible 

injury, and O = no apparent injury.

NA = Not applicable.

NASS = National Automotive Sampling System.

NCSA = National Center for Statistics and Analysis.

PAR = Police accident report.

PSU = Primary sampling unit.

Table 6. Resource databases to support DCMF efforts (FARS, GES, CDS, NMVCCS) (continued).
38

CIREN MC STARS

Who houses and maintains the data? NHTSA FMCSA NPS

What is the spatial coverage of the data?

Sample of crashes collected by CIREN teams, which consist 

of three medical centers and three engineering centers in 

Washington, Wisconsin, Virginia, Maryland, and Alabama.

All registrations, inspections, investigations, and qualifying 

crashes involving motor carriers with USDOT numbers within 

the 50 States, the District of Columbia, and Puerto Rico.

All motor vehicle collisions that occur within NPS jurisdiction.

What years of data are in the database? 1996 to 2011 1989 to present 1990 to 2005

What is the general availability of the 

data?

Online: http://www.nhtsa.gov/Research/

Crash+Injury+Research+(CIREN)/Data

Available to the general public through the MCMIS Data 

Dissemination Program with a fee, formal request needed. 

Selected data available online at http://ai.fmcsa.dot.gov/

default.aspx.

No direct access online, formal request needed.

How are the data collected? How are the 

data coded?

Each Center collects detailed crash and medical data on 

about 50 crashes per year. Personal and location identifiers 

and highly sensitive medical information have been removed 

from the public files to protect patient confidentiality; 650 

NASS CDS data elements and 250 medical and injury data 

elements coded.

Daily updates from State and FMCSA field offices through the 

microcomputer system SAFETYNET, CAPRI, and other sources. 

The data are coded for: crash variables, census variables, and 

inspection variables. Inspection data is primarily conducted at 

the roadside by State personnel under MCSAP.

Obtained from Motor Vehicle Accident Report. The data is 

coded for crash variables.

Does the database include all crashes for 

the coverage area (i.e., the population) or 

just a portion of the crashes (i.e., a sample)?

Includes only crashes with serious injury. Includes only reported crashes involving commercial motor 

carriers (large truck & bus) and hazardous material carriers. All reported crashes.

How are crash severity levels defined? ISS/MAIS Scale

National Governors’ Association crash thresholds. 

Injury crashes: person injured is immediately taken to a 

medical facility. 

Tow-away crashes: at least one vehicle is towed from the 

scene as a result of disabling damage suffered in the crash.

Fatal, Injury, PDO

What is the vehicle type coverage? All vehicle types. Large trucks, buses, and any vehicle with a hazmat placard. All vehicle types.

If data is just a sample, how was the 

sampling done?

Admission to participating CIREN Center. Severely injured 

and transported to Level 1 trauma center. Injury required: 1) at 

least one AIS3+ injury, 2) AIS2 injury in two different AIS body 

regions, 3) significant particular injury to a lower extremity 

(AIS2). Vehicle model no older than 6 years. Restraint: 1) frontal 

crash–air bag and/or belt required, 2) side impact–unbelted is 

acceptable, 3) rollover–eject occupants are excluded.

NA NA

If just a sample, what (if any) guidance 

is given to incorporate the sampling 

procedure into data analysis?

None NA NA

Table 7. Resource databases to support DCMF efforts (CIREN, MCMIS, STARS).
39

CIREN MC STARS

To which Tasks (A–D) is the database 

applicable?

General: Conduct research related to vehicles, occupants, and 

non-motorized road users involved in a crash (e.g., identify 

motor vehicle design features that offer maximum occupant 

protection).

C: Support and advance innovation in safety countermeasures 

to further reduce crash fatalities and severe injuries 

associated with prioritized safety needs.

D: Determine priority research needs that have not been 

identified

General: Support and evaluate motor carrier safety programs 

and regulations.

C: Support and advance innovation in motor carrier-related 

safety countermeasures to further reduce crash fatalities 

and severe injuries associated with prioritized safety needs.

D: Determine priority research needs related to motor carriers 

that have not been identified.

General: Support and evaluate motor carrier safety programs 

and regulations.

C: Support and advance innovation in motor carrier-related 

safety countermeasures to further reduce crash fatalities 

and severe injuries associated with prioritized safety needs.

D: Determine priority research needs related to motor carriers 

that have not been identified.

Note: the NPS STARS database may have limited potential 

for the DCMF project and future efforts to advance CMF 

development.

Table 7. Resource databases to support DCMF efforts (CIREN, MCMIS, STARS) (continued).

AIS = Abbreviated injury scale.

CAPRI = Compliance analysis and performance review information.

CIREN = Crash Injury Research and Engineering Network.

ISS = Injury severity score.

MAIS = Modified abbreviated injury scale.

MCMIS = Motor Carriers Management Information System.

MCSAP = Motor Carrier Safety Assistance Program.

NPS = National Park Service.

PDO = Property damage only.

STARS = Service-wide Traffic Accident Reporting System.
40

NTD NEMSIS SHRP2

Who houses and maintains the data? FTA NHTSA Office of Emergency Medical Services TRB

What is the spatial coverage of the data? National transit-related reportable incidents. National repository for EMS data. As of 2012, there are 42 

States and territories that are contributing to the dataset.

The NDS data and roadway information database (RID) were 

based on data gathered in six States (FL, IN, NY, NC, PA, and WA).

What years of data are in the database? 2002 to 2013 2008 to 2012 2010 to 2013

What is the general availability of the 

data? Online: http://www.ntdprogram.gov/ntdprogram/data.htm Online request: http://www.nemsis.org/reportingTools/requestNEMSISData.html To be determined

How are the data collected? How are the 

data coded?

The system derives data from transit providers, States, or 

MPOs that are recipients and beneficiaries of grants. There 

are 55 data fields that are collected from six different forms 

for safety and security. 

The NEMSIS project was developed to help States collect 

more standardized elements and eventually submit the data 

to a national EMS database. 

The NDS data were collected by instrumenting vehicles to record 

vehicle location, forward radar, vehicle control positions (e.g., 

turn signals, brake pedal activation, ABS, gear position, speed, 

horn, and steering wheel angle), acceleration, alcohol use, cell 

phone use, and video of the forward roadway and of the driver’s 

face and hands. Crash investigations were conducted after some 

crashes to gather detailed data.

The RID contains new roadway data gathered by automated 

data collection vehicles and existing data provided by agencies 

(i.e., State transportation departments, MPOs, and counties). The 

roadway data includes roadway inventory information, crash 

histories, traffic, weather, roadway improvements, work zones, 

safety laws, and enforcement campaigns. 

Does the database include all crashes for 

the coverage area (i.e., the population) or 

just a portion of the crashes (i.e., a sample)?

The database includes transit-related reportable incidents. 

Note that not all incidents are considered to be reportable. 

If an incident is not related to and does not affect revenue 

operations, then it is considered to be non-reportable.

Includes only reported crashes involving commercial motor 

carriers (large truck & bus) and hazardous material carriers.

The NDS database includes detailed data on more than 5 million 

trips, 49 million travel miles, and 1.4 million driving hours from 

more than 3,100 participants of various ages across the country. 

The database represents continuous data from all trips taken by 

volunteer participants over one to two years. 

The RID contains approximately 12,500 centerline miles and the 

existing data contains more than 200,000 centerline miles. 

How are crash severity levels defined? Incidents, injuries, fatalities Possible injury (yes/no) Unknown

What is the vehicle type coverage?

Transit vehicles, including the following modes: Automated 

Guideway, Commuter Bus, Cable Car, Demand Response, 

Demand Response-Taxi, Ferryboat, Inclined Plane, Heavy Rail, 

Jitney, Light Rail, Motor Bus, Monorail/Guideway, Monorail, 

Público, Bus Rapid Transit, Streetcar Rail, Trolleybus, Aerial 

Tramway, Vanpool, and Hybrid Rail.

All vehicle types. Passenger vehicles, including passenger cars, minivans, SUVs, 

and pickup trucks.

If data is just a sample, how was the 

sampling done? NA States vary in criteria used to determine the types of EMS events submitted to the NEMSIS dataset.

Six locations were selected in the United States to represent 

geographic diversity and to provide a range of driver, vehicle, 

and roadway conditions.

Table 8. Resource databases to support DCMF efforts (NTD, NEMSIS, SHRP2).
41

NTD NEMSIS SHRP2

If just a sample, what (if any) guidance 

is given to incorporate the sampling 

procedure into data analysis?

NA No No

To which Tasks (A–D) is the database 

applicable?

General: United States’ primary source of transit system 

information and statistics. Investigate transit-related crashes, 

including the injuries and fatalities by type and mode.

C: Support and advance innovation in transit-related safety 

countermeasures to further reduce fatalities and severe 

injuries associated with prioritized safety needs.

D: Determine priority research needs related to transit that 

have not been identified.

General: Evaluate patient and EMS system outcomes.

General (Note: the following list provides examples of potential 

uses of SHRP2 data):

• Understand the contributing and causal factors in crashes.

• Understand how the driver interacts with and adapts to the 

vehicle, traffic, roadway characteristics, traffic control devices, 

and the environment. 

• Identify the relationship between crashes, conflicts, and crash 

surrogates. 

• Formulate exposure-based risk measures using surrogate 

measures. 

• Investigate the potential for new countermeasures related 

to the design of the roadway and vehicles as well as public 

policy and enforcement.

• Enhance driver training programs to demonstrate appropriate 

and inappropriate driver behavior.

• The RID provides a model for developing linked data sets for 

asset management purposes.

Table 8. Resource databases to support DCMF efforts (NTD, NEMSIS, SHRP2) (continued).

ABS = Anti-lock braking system.

EMS = Emergency medical services.

FTA = Federal Transit Administration.

MPO = Metropolitan Planning Organization.

NEMSIS = National Emergency Medical Services Information System.

NTD = National Transit Database.

SUV = Sport utility vehicle.
42

HSIS

California Illinois Maine Minnesota North Carolina Ohio Washington

Who houses and maintains 

the data? University of North Carolina HSRC under contract with FHWA.

What is the spatial coverage 

of the data? Statewide

What years of data are in the 

database?

1991 to present (data 

typically lag by 1–2 years) 

1985 to present (data 

typically lag by 1–2 years)

1985 to present (data 

typically lag by 1–2 years)

1985 to present (data 

typically lag by 1–2 years)

1991 to present (data 

typically lag by 1–2 years)

1997 to present (data 

typically lag by 1–2 years)

1993 to present (data 

typically lag by 1–2 years); 

1997 and 1998 crash data 

are not included

What is the general 

availability of the data? Data can be provided via different mediums (CD-ROM, FTP, email). The data can be requested by filling out an HSIS data request form online at the HSIS Web site.

How are the data collected? 

How are the data coded?

Annually derived from 

California TASAS. The 

data are coded for: crash 

variables, roadway 

variables, intersection 

variables, interchange 

variables, and traffic 

variables.

Annually derived from 

Illinois safety information 

system, which includes a 

number of data edits and 

quality checks. The data are 

coded for: crash variables, 

roadway variables, 

interchange variables, 

curve/grade variables, and 

traffic variables.

Annually derived from 

Maine TINIS. The data are 

coded for: crash variables, 

roadway variables, 

intersection variables, 

interchange variables, and 

traffic variables.

Annually derived from 

Minnesota data system. 

The data are coded for: 

crash variables, roadway 

variables, intersection 

variables, interchange 

variables, and traffic 

variables.

Annually derived from an 

Oracle database on the 

NCDMV system. Before 

2000, it was derived from 

a mainframe database 

maintained by the NCDOT. 

The data are coded for: 

crash variables, roadway 

variables, and traffic 

variables.

Annually derived from 

Ohio data system. The 

data are coded for: crash 

variables, roadway 

variables, curve and grade 

variables, and traffic 

variables.

Annually derived from 

Washington TRIPS system. 

The data are coded for: 

crash variables, roadway 

variables, interchange 

variables, curve/grade 

variables, and traffic 

variables.

Does the database include all 

crashes for the coverage area 

(i.e., the population) or just a 

portion of the crashes (i.e., a 

sample)?

All reported crashes, primarily on the State-maintained system. This varies slightly by State.

How are crash severity levels 

defined?

KABCO/five-point scale, 

plus error/other codes

KABCO, plus: not coded, 

error codes

KABCO, plus: unknown, 

error/other codes

KABCO, plus: not 

applicable, unknown if 

injured

KABCO, plus: unknown KABCO Nine-point scale

What is the vehicle type 

coverage?

All vehicle types, 

distinguished between 

vehicle makes, types and 

model years.

All vehicle types. All vehicle types. All vehicle types. All vehicle types. All vehicle types. All vehicle types.

If data is just a sample, how 

was the sampling done? NA NA NA NA NA NA NA

Table 9. Resource databases to support DCMF efforts (HSIS).
43

HSIS

California Illinois Maine Minnesota North Carolina Ohio Washington

If just a sample, what (if 

any) guidance is given to 

incorporate the sampling 

procedure into data analysis?

NA NA NA NA NA NA NA

To which Tasks (A–D) is the 

database applicable?

General: The HSIS database has numerous general applications, as do many of the databases listed in this document.

A: Prioritize current CMF research needs based on the magnitude and severity of crashes at specific locations (e.g., curves, intersections, segments).

B: Prioritize future CMF research needs based on the magnitude and severity of crashes at specific locations (e.g., curves, intersections, segments).

C: Support and advance innovation in safety countermeasures to further reduce crash fatalities and severe injuries associated with prioritized safety needs.

D: Determine priority research needs that have not been identified based on the investigation of crashes and crash severity at specific locations (e.g., curves, intersections, segments).

Table 9. Resource databases to support DCMF efforts (HSIS) (continued).

CD-ROM = Compact disc, read-only-memory.

HSRC = Highway Safety Research Center.

NCDMV = North Carolina Department of Motor Vehicles.

TASAS = Traffic Accident Surveillance and Analysis System.

TINIS = Transportation Integrated Network Information System.

TRIPS = Transportation Information and Planning Support System.
44

References

1. U.S. Department of Transportation, Crash 

Modification Factors (CMF) Clearinghouse Web 

site, Federal Highway Administration, McLean, 

VA, http://www.cmfclearinghouse.org/collateral/

CMFGuide.pdf. 

2. International Transport Forum, Sharing Road 

Safety: Developing an International Framework for 

Crash Modification Functions, OECD Publishing, 

Paris, November 2012, http://www.international

transportforum.org/Pub/pdf/12Sharing.pdf.

3. Zegeer, C., Srinivasan, R., Carter, D., Council, F., 

Gross, F., Sawyer, M., Hauer, E., Bonneson, J., 

and Bahar, G., Highway Safety Research Agenda: 

Infrastructure and Operations, NCHRP Report, 

Issue 756, 2013, 101p.

4. National Strategy on Highway Safety, Toward 

Zero Deaths: A National Strategy on Highway 

Safety, http://www.towardzerodeaths.org/

strategy.php.

5. Harkey, D., Council, F., Srinivasan, R., Lyon, 

C., Persaud, B., Eccles, K., Lefler, N., Gross, F., 

Baek, J., Hauer, E. and Bonneson, J., NCHRP 

Report 617: Accident Modification Factors for 

Traffic Engineering and ITS Improvements, 

Transportation Research Board, Washington, 

DC, 2008, http://onlinepubs.trb.org/onlinepubs/

nchrp/nchrp_rpt_617.pdf.

6. Zegeer, C., Nabors, D., Gelinne, D., Lefler, N., and 

Bushell, M., Pedestrian Safety Strategic Plan: 

Recommendations for Research and Product 

Development, Report FHWA-SA-10-035, Federal 

Highway Administration, Washington, DC, 2010.

7. National Highway Research and Technology 

(R&T) Partnership, Highway Research and 

Technology—The Need for Greater Investment, 

April 2002. 

8. AAA Foundation for Traffic Safety, Traffic Safety 

Issues of the Future: A Long Range Research 

Agenda, January 2006, https://www.aaafounda

tion.org/sites/default/files/FuturesReport.pdf.

9. Transportation Research Board, Safety Research 

on Highway Infrastructure and Operations: Improving Priorities, Coordination, and Quality, TRB 

Special Report 292, Washington, DC, 2008, http://

onlinepubs.trb.org/Onlinepubs/sr/sr292.pdf. 

10. Boyle, L. N., Hallmark, S., Lee, J. D., McGehee, D. 

V., Neyens, D. M., and Ward, N. J., Integration of 

Analysis Methods and Development of Analysis 

Plan, SHRP 2 Report S2-S02-RW-1, Transportation 

Research Board, Washington, DC, 2012, http://

www.trb.org/Publications/Blurbs/166051.aspx.

11. Carter, D., Srinivasan, R., Gross, F., and Council, 

F., Recommended Protocols for Developing Crash 

Modification Factors, NCHRP, Transportation 

Research Board, Washington, DC, February 2012, 

http://www.cmfclearinghouse.org/collateral/

CMF_Protocols.pdf.

12. Banks, D., Persaud, B., Lyon, C., Eccles, K., and 

Himes, S., Enhancing Statistical Methodologies 

for Highway Safety Research—Impetus 

from FHWA, White Paper, Federal Highway 

Administration, McLean, VA, May 2014.
45

Researchers—This study was performed by Frank Gross and Kimberly Eccles of VHB, and Daniel 

Carter of the UNC Highway Safety Research Center.

Distribution—This Summary Report is being distributed according to a standard distribution. 

Direct distribution is being made to the Divisions and Resource Center.

Availability—The report can be obtained from the FHWA Product Distribution Center by e-mail to 

report.center@dot.gov, by fax to (814) 239-2156, or by phone to (814) 239-1160. 

Key Words—Safety, highway safety, crash modification factors, CMFs, research methods, statistical 

methods, needs assessment, gap analysis, stakeholders, countermeasures, strategies.

Notice—This Summary Report is disseminated under the sponsorship of the U.S. Department of 

Transportation in the interest of information exchange. The U.S. Government assumes no liability for 

the use of the information contained in this document. The U.S. Government does not endorse 

products or manufacturers. Trademarks or manufacturers’ names appear in this Summary Report 

only because they are considered essential to the objective of the document.

Quality Assurance Statement—The Federal Highway Administration (FHWA) provides highquality information to serve Government, industry, and the public in a manner that promotes 

public understanding. Standards and policies are used to ensure and maximize the quality, 

objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and 

adjusts its programs and processes to ensure continuous quality improvement.

MARCH 2015 FHWA-HRT-15-020

HRDS-20/03-15(WEB)