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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

 
SUMMARY REPORT
This summary report is an archived publication and may contain dated technical, contact, and link information
Publication Number:  FHWA-HRT-15-020    Date:  March 2015
Publication Number: FHWA-HRT-15-020
Date: March 2015

 

Crash Modification Factors Needs Assessment Workshop

 

FHWA-HRT-15-020 Header Image

Publication No. FHWA-HRT-15-020

FHWA Contact: Roya Amjadi, HRDS-20, 202-493-3383, roya.amjadi@dot.gov

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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.

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 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:

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:

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 5 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 5 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

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 CMF-related 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:

Figure 1. Illustration. HSIS States. This illustration features a map of the 48 contiguous States. All of the States are gray except for California, Washington State, Minnesota, Illinois, Ohio, North Carolina, and Maine (which are red) and Utah and Michigan (which are light pink). There is a key at the bottom of the map that indicates that the red states are active participants in the Highway Safety Information System, and the light pink states are historical participants.
Figure 1. HSIS States

FHWA Office of Safety

Karen Scurry provided an overview of the CMF-related 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 Development Efforts

FHWA Resource Center

Patrick Hasson provided an overview of the CMF-related 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:

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:

More in line with CMFs, FMCSA has developed the following two models to assess the effectiveness of its safety programs:

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:

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:

American Association of State Highway Transportation Officials (AASHTO)

Kelly Hardy provided an overview of the CMF-related 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 standards-setting 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:

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:

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 pre–crash, 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:

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:

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:

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:

CMF Gap Analysis and Research-Needs 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:

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.

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.

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:

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.

Table 2. General structure for identifying gaps.

Perceived Need

Comparison to Resource Database

Category

Countermeasure

Applicable
Scenario

Source
Existing/
Forthcoming
CMFs

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

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 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:

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:

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:

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 cross-sectional design. For the before-after design, the CMF is estimated from the change in crash frequency between the periods efore 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 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 regression-based 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-to-the-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 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.

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 before-after 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.

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:

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):

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.

CMF Opportunities

The following is a summary of existing CMF efforts and future opportunities:

Data and Methods

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

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:

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:

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:

Appendix A: CMF Stakeholders

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

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.qazi@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

Illinois

Priscilla Tobias

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

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.gov

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 Carolina

Joey Riddle

South Carolina Department of Transportation

riddlejd@scdot.org

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.gov

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.gov

Andrea Bill

University of Wisconsin-Madison

bill@wisc.edu

 

Table 5. USDOT and Partner Agencies

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 Johnson

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
202-789-0942 x130

ITS JPO

Kate Hartman

kate.hartman@dot.gov

Kevin Dopart

kevin.dopart@dot.gov

Mike Pina

michael.pina@dot.gov

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

leggb@wsdot.wa.gov
360-705-7994

Ginny Crowson

crowson@acconsultants.org
651-600-3338

CVSA = Commercial Vehicle Safety Alliance.
GHSA = Governors Highway Safety Association.
JPO = Joint Program Office.

USDOT and Partner Agencies

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

The contacts from each group are listed in table 5.

Appendix B: CMF Stakeholder Meeting Agenda

APPENDIX C: RESOURCE DATABASES TO SUPPORT DCMF EFFORTS

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

 

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.

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

 

CIREN

MCMIS

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

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 NPS safety programs and regulations.

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.

Note: the NPS STARS database may have limited potential for the DCMF project and future efforts to advance CMF development.

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.

 


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

 

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.

Events submitted by States do not necessarily represent all EMS events occurring within the State.

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.

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.

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.

 

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

 

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 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

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).

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.


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.internationaltransportforum.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.aaafoundation.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.

 

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.

Key Words—Safety, highway safety, crash modification factors, CMFs, research methods, statistical methods, needs assessment, gap analysis, stakeholders, countermeasures, strategies.

Notice—This document 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 provides high–quality 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.

 

 

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