U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
The report provides noteworthy examples or applications of policy or procedures statements along with the sample language. The selected State Department of Transportation (DOT) examples or applications cover specific areas in the project development process, including planning and programming, engineering and design, operations, and maintenance, and roadway safety management processes.
Federal requirements state that safety must be explicitly considered in the transportation planning process. In addition, Federal legislation requires that transportation agencies prepare strategic highway safety plans, long-range transportation plans, and other statewide plans. Integrating safety into long-term system plans (20-year plans) provides highway agencies with the ability to set the vision, goals, and strategies to proactively develop transportation systems that will result in fewer fatalities and serious injuries. Near-term planning (5- to 10-year project planning) also provides the opportunity to plan and program projects to address known safety issues or integrate safety features into projects focused on other transportation services such as mobility, maintenance, connectivity, or access. The programming process allocates funds to projects according to an ongoing cycle–often a four-year cycle at the State level. Analysis methods identified in the Highway Safety Manual (HSM) can be used to support decisionmaking in the long-term planning process, project-planning process, and project-prioritization process.
The long-range transportation planning process can broadly be defined as having the following elements:
Data collection and analysis to identify needs, priorities, policies, programs, and projects.
Goals and objectives to frame those needs and priorities and establish evaluation criteria.
Performance measures and targets to evaluate alternatives and track progress towards the goals and objectives.
Project analysis, prioritization, and programming to identify the mix of projects that meet the goals and objectives of the plan and help to make progress towards the performance target.
Evaluation to understand the extent to which safety performance for the transportation system, modes, or behaviors is changing and where future investments can be made. (See U.S. Department of Transportation, Federal Highway Administration, Performance Based Planning and Programming Guidebook, September 2013.)
Descriptive safety data analyses can be used to establish goals, objectives, and performance measures for a long-range transportation plan. Also, safety data is an important component of the examination of current conditions for a transportation system. As explained in the HSM, descriptive analyses summarize and tabulate information about crashes such as crash frequency, severity, or type using crash counts. (American Association of State Highway and Transportation Officials, Highway Safety Manual, 1st Edition, 2010, p. 5-2.) Forecasting safety performance of a transportation network can be done using network-level safety forecasting methods provided in the HSM; however, the models would have to be very comprehensive to match the scale of most State and urban transportation networks. As planning activities become more project specific (near-term planning or programming activities), the HSM Part C predictive method and/or Crash Modification Factors (CMF) in the HSM become more relevant.
It is the policy of the Department that HSM methods shall (should/may) be used in long-range plans to identify projects, programs, or policies that support safety goals and objectives in the plan.
To implement this policy, the HSM methodologies shall (should/may) be used in the long-range transportation planning process. Descriptive analyses summarizing statewide and/or regional crash trends (e.g., crashes by type, urban or rural, behavior) can provide information about the types of projects which might drive down fatalities and serious injuries. State or regionwide safety prediction models can be developed and used to estimate future safety conditions and evaluate alternative transportation system scenarios.
In near-term transportation planning and programming, projects are assessed, project alternatives are considered and defined, project purpose and need are developed, and projects are prioritized and programmed (i.e., funding is committed for design and construction). (The section"Near-Term Transportation Planning and Programming" does not provide an exhaustive list of near-term planning and programming activities.) The HSM can be readily integrated into the near-term planning and programming process to incorporate consideration of the safety performance of various roadway features, as well as comparing one project to another for prioritization.
For example, the Illinois Department of Transportation (IDOT) Safer Roads Index (SRI) uses HSM concepts in its transportation programming process; Virginia Department of Transportation (VDOT) is using planning-level CMFs in its project funding prioritization process through its Smart Scale program; and Louisiana Department of Transportation and Development (LADOTD) has a fact sheet linking its project development process to types of safety analyses methods from the HSM.
Example Application: The Illinois Department of Transportation enhanced its approach to incorporating safety into IDOT's overall transportation management process by establishing the Safer Roads Index and Safety Tiers for State-maintained routes. The goal is to improve the integration of quantitative safety performance in transportation project planning and programming. The SRI is now being used in planning and programming and is being considered alongside pavement condition and bridge condition factors to improve selection and prioritization of transportation projects.
Example Application: The Virginia Department of Transportation's Smart Scale established a project prioritization and scoring process to improve transparency of projects selected for funding. Safety is one of six factors and each factor has several measures. The safety measures identify the number of fatal and severe injury crashes and rate of fatal and severe injury crashes. VDOT developed a set of planning-level CMFs for use in the prioritization process. A presentation about the planning-level CMFs used in the prioritization is also available.
Example Application: The Louisiana Department of Transportation and Development has a "Highway Safety Manual Project Applications" fact sheet containing guidance regarding which methods from the HSM should be used for different parts for the LADOTD project development process. Among other items, the fact sheet recommends the HSM Part C predictive method or CMFs for planning-level project or corridor studies to evaluate alternatives.
It is the policy of the Department to select and implement projects that help the State achieve its safety goals with consideration given to the cost effectiveness of the potential projects and funding constraints. The HSM shall (should/may) be used to evaluate project alternatives and prioritize projects to quantitatively consider safety performance in the near-term planning and programming process.
To implement this policy, the HSM methodologies shall (should/may) be used to integrate quantitative safety analysis in the near-term planning and programming of funding for transportation projects. Quantitative safety analysis allows for safety performance to be estimated and therefore tradeoffs between alternatives or across projects defined. Safety (i.e., number and severity of crashes) can be considered alongside other performance measures such as capacity, environmental impacts, right-of-way impacts, or construction costs. The HSM Part C predictive method and/or CMFs can be used to estimate the changes in crash frequency or severity associated with different roadway alternatives. The tradeoffs can be considered in the form of the number of crashes, the number of fatalities or severe injuries, or the economic costs of the crashes.
The National Environmental Policy Act (NEPA) requires examination of potential impacts to the social and natural environment when considering proposed transportation projects involving Federal funds or requiring Federal approval. (U.S. Department of Transportation, Federal Highway Administration,"Integrating Road Safety Into NEPA Analysis; A Practitioners Primer," June 2011, page 3). There are three major categories of NEPA assessment: Categorical Exclusions (listed or documented), Environment Assessments, and Environmental Impact Statements. (U.S. Department of Transportation, Federal Highway Administration,"Integrating Road Safety Into NEPA Analysis; A Practitioners Primer," June 2011, page 4). The HSM Part C predictive method and CMFs readily support the evaluation of alternatives that are under consideration in the NEPA process. Examples of HSM-related language in State DOT NEPA procedures were not identified in this project; possible language is presented below.
It is the policy of the Department that safety shall be a consideration in the NEPA project alternatives evaluation and documentation. The existing crash conditions and estimated number and severity of crashes associated with the no-build and build alternatives shall (should/may) be estimated using HSM methods. The outcomes of the quantitative safety analyses shall be considered and documented.
To implement this policy, safety can be meaningfully integrated into the NEPA process by estimating changes in crash frequency or severity associated with different alternatives being investigated. Changes in crash frequency or severity due to different roadway features shall (should/may) be estimated using the HSM Part C predictive method and/or CMFs.
Within the process of delivering a roadway project for construction, engineering-and more specifically engineering design–consumes a large share of the effort and time required. The design process can be an iterative effort starting from a high-level concept to more detailed design and analysis, resulting in a complete final design of the facility. This report focuses on integrating the HSM into three categories of engineering and design:
Preliminary engineering encompasses a wide range of practices with a roadway project. In this informational report, preliminary engineering is narrowly centered on activities that would be considered during the concept or scoping phases of a project prior to design. Example language related to preliminary engineering was discovered through the research for this report only in the following areas:
As part of the preliminary engineering process, project-level traffic impact analyses are an excellent opportunity to use the HSM to evaluate safety performance.
It is the policy of the Department for traffic impact analyses to include a safety performance assessment. For the decisionmaking process within preliminary engineering activities, these analyses provide valuable information to evaluate the safety performance regarding changes to access the roadway system, the roadway design, and the resulting traffic impacts. The HSM shall (should/may) be used in traffic impact analyses to evaluate the safety performance associated with modifications to the roadway.
To implement this policy a Traffic Impact Analysis shall be prepared during the preliminary engineering phase of a project and shall include an assessment of safety performance as a key component of the TIA. In this analysis, CMFs are a useful tool that shall (should/may) be used to estimate the anticipated safety impacts of the proposed roadway modifications or design.
In addition to the CMFs, the HSM Part C predictive method is a valuable tool in this assessment process and shall (should/may) be used to compare the safety performance with or without proposed modifications for the design of the highway.
As part of the process to change access to the Interstate highway system, the FHWA's decision to approve new or revised access points to the Interstate highway system requires documentation of the impacts of the proposed access. The Interstate System Access Change Request is used to describe the formal request made to FHWA by a State DOT. With this process, the FHWA's interest is to ensure all new or revised access points:
Are considered using a decisionmaking process that is based on information and analysis of the planning, environmental, design, safety, and operational affects [sic] of the proposed change.
Do not have an adverse impact on the safety or operations of the Interstate System and connecting local roadway network or other elements of the transportation system.
As part of this FHWA policy, requests for a proposed change in access must include a description and assessment of the impacts and ability of the proposed changes to safely and efficiently collect, distribute and accommodate traffic. (FHWA Access Guide, p. 82.) The HSM can be used to complete the required safety performance assessment.
Example Language: Florida Department of Transportation (FDOT)–The objective of this safety analysis is to examine the effects of the proposed new access or modified access on the performance of the facility. As such, the safety analysis should proactively aim at reducing or correcting potential safety problems in the planning and design phase of the projects before they are constructed. For build alternatives analysis the Requester may use new tools for quantitative analysis of safety performance to predict crashes and compare the safety performance of the alternatives. Safety analysis tools that may be used are the Highway Safety Manual published in 2010 and enhanced Interchange Safety Analysis Tool (ISATe). Additional tools that can be used to perform Safety Analysis are Interactive Highway Safety Design Model (IHSDM) and SafetyAnalyst. (“SafetyAnalyst" refers to AASHTOWare Safety Analyst.) Source: Florida Department of Transportation,"FDOT Interchange Access Request–User's Guide," 2013.
Example Language: Illinois Department of Transportation (IDOT)–The Access Justification Report (AJR) should include the following: Highway Safety Analysis. Use the 2014 Supplement to the Highway Safety Manual (HSM), or the Enhanced Interchange Safety Analysis Tool (ISATe), for the needed safety analysis. Source: Illinois Department of Transportation,"New or Revised Interstate Access Approval," 2015.
Example Language: Washington State Department of Transportation–Identify and document the predicted safety performance of the proposed access point revision proposal(s), including the freeway section, speed change lanes, ramps, collector/distributor (c-d) lanes, ramp terminal intersections, and the adjacent affected local surface system, including segments and intersections. Document the predicted safety performance of the freeway section using the Highway Safety Manual (to access ISATe), speed change lanes, ramps, c-d lines, ramp terminal intersections, and the adjacent affected local surface system, including segments and intersections within the study limits for each of the proposed"no-build,""build," and possibly other scenarios and alternatives as determined by the support team. Source: Washington State Department of Transportation (WSDOT), Engineering and Regional Operations Development Division, Design Office,"Design Manual, Chapter 550" (M 22 01.12. November), 2015.
It is the policy of the Department to protect the functionality of the Interstate system and preserve the investment made in the system. With all proposed new or modified access to the Interstate system, an access justification report shall be completed and safety performance shall be an evaluation consideration in the report. The objective of an access justification safety analysis is to examine the effects of the proposed new access or modified access on the safety performance of the facility. This safety analysis is a proactive approach to address potential safety impacts identified in the planning and design phase of the project. When completing the safety analysis, HSM methods shall (should/may) be used to evaluate the safety performance of project design alternatives.
To implement this policy the Interstate access justification report shall include a quantitative assessment of the safety impacts of the proposed access modification. This quantitative assessment shall (should/may) use the HSM Part C predictive method to evaluate predicted safety performance of the proposed access change, including the freeway section, speed change lanes, ramps, collector/distributor lanes, ramp terminal intersections, and the adjacent affected local surface system, including segments and intersections.
The Interactive Highway Safety Design Model (IHSDM), Enhanced Interchange Safety Analysis Tool (ISATe), and/or HSM spreadsheets are available tools that can be used to support this safety performance assessment. In addition, CMFs from the CMF Clearinghouse and/or State-specific CMFs developed by the Department can be used in the safety performance assessment.
Design manuals provide the practices and methods for developing and documenting the design of improvements to the transportation network. The highway design process involves the application of engineering principles to meet each project's objectives in the best overall public interest. Application of these principles requires considering and balancing social, economic, and environmental issues to achieve a safe and efficient transportation system. The design manual supplements the engineering analyses and judgment that is applied to project design. It provides uniform procedures for documenting and implementing design decisions.
Example Language: Washington State Department of Transportation–The HSM and associated analysis tools have been developed to aid decisionmaking and documentation in the project development process. It helps quantify safety performance implications of decisions in project development and provides a basis for predicting and documenting the potential safety performance of those decisions. Safety analysis tools may be appropriate for design decisions to analyze and document the safety performance of design alternatives and design element dimensioning decisions, including cross section design element dimensioning and other countermeasures treatment options. Source: Washington State Department of Transportation, Engineering and Regional Operations Development Division, Design Office,"Design Manual, Chapter 321" (M 22 01.12. 321.06 November), 2015.
Example Language: Pennsylvania Department of Transportation (PennDOT)–A safety assessment, including the potential safety benefits shall be discussed if the proposed improvements will contribute to a reduced number and/or severity of crashes. Consider using American Association of State Highway Transportation Officials' (AASHTO) Highway Safety Manual (HSM) to calculate crash frequencies to quantify the substantive safety performance of the alternatives. Source: Pennsylvania Department of Transportation,"District Highway Safety Guidance Manual," (Publication PUB 638 (12-14)). December 2014.
Example Language: Georgia Department of Transportation (GDOT)–“Design Policy Manual 2015–Roundabout Feasibility Study." A feasibility study must be prepared for all proposed roundabouts. The objective of the feasibility study is to document the decisionmaking process which demonstrates that a roundabout is (or is not) the most appropriate intersection control form. A feasibility study should include the following components: section 2, Safety Assessment: include a tabulated analysis of intersection crash data for the five most recent years for which data is available and a comparison to statewide intersection averages. Crash reductions factors should be obtained either from the FHWA Report No. FHWA-SA-08-01,1 Desktop Reference for Crash Reduction Factors or the Crash Modification Factors Clearinghouse Web site. Further information regarding safety and roundabouts is presented in chapter 5 of NCHRP 672 and in the AASHTO Highway Safety Manual. Source: Georgia Department of Transportation,"Design Policy Manual," 2015.
It is the policy of the Department that the HSM shall (should/may) be used to evaluate the safety performance of the roadway design. Using the HSM to determine design tradeoffs (higher-than-minimum standards or lower-than-full standards) will meet the intent of the design manual for determining recommended values or range of values for the roadway design.
To implement this policy, the designer shall (should/may) evaluate using the HSM the safety performance of the proposed design elements as part of the decisionmaking process determining the presence and dimensions of the proposed design features. The HSM Part C predictive method and/or CMFs are resources available to complete this assessment. The sources of CMFs are the HSM Part D, the CMF Clearinghouse, and/or State-specific CMFs developed by the Department.
The documentation of safety analyses supporting (or informing) design decisions is the responsibility of the office completing the design. Components of this documentation include the safety analyses used, and a safety impact comparison of design alternatives. Also, by performing predictive safety analysis and incorporating existing crash history when appropriate, the designer shall (should/may) conduct a safety performance assessment to identify the contributing factors and determine the appropriate countermeasures to include in the design based on these factors.
The Interactive Highway Safety Design Model (IHSDM), Enhanced Interchange Safety Analysis Tool (ISATe), and/or HSM spreadsheets are available tools that can be used to support the safety performance assessment.
As a component of the safety analysis documentation, the designer shall (should/may) complete an economic assessment to support evaluation of different design alternatives. For this documentation, the HSM chapter 7–Economic Appraisal identifies various methods that shall (should/may) be used for the economic analysis, including benefit/cost (B/C), net present value, and cost effectiveness analysis.
The design exception process provides an excellent opportunity to expand HSM policy and guidance/procedure language as well as overall HSM implementation outside of the Highway Safety Improvement Process or other typical safety programs. This"process" term should be considered to be inclusive of design exceptions, design variances, design waivers, or other terms used in State DOT documents.
Example Language: Ohio Department of Transportation (ODOT)–Design exception documentation will be based upon the analysis of the three-year crash history performed at the time of scoping. Projects can use the Safety Analyst Locations for Design Exception Process Maps or Spreadsheet to perform this analysis. Alternatively, one may complete the calculations included in AASHTO's Highway Safety Manual with Ohio-specific proportional tables and calibration factors. ODOT has developed a spreadsheet tool to aid in completing the HSM calculations called the Economic Crash Analysis Tool (ECAT). Source: Ohio Department of Transportation,"Design Controls and Exceptions," January 2014.
Example Language: Missouri Department of Transportation (MoDOT)–If the design exception request involves safety-related features that are adequately addressed in the AASHTO Highway Safety Manual, then documentation of the exception should include a safety analysis as described in the manual. In general, this safety analysis should compare the expected number of crashes for the facility with the design exception to the expected number of crashes of the facility without the design exception. Currently, not all safety-related features are explicitly addressed in the Highway Safety Manual. A list of features currently addressed by the manual include: lane width, shoulder width, shoulder type, center line rumble strips, horizontal alignment (length, radius), grade, roadside hazard rating, fixed objects, driveway density, median width, side slope, lighting, intersection skew angle, and turn lanes. Not all features in the manual are addressed for each facility type. Source: Missouri Department of Transportation,"Design Exception Process," 2015.
Example Language: Pennsylvania Department of Transportation–Confidential Safety Study. The purpose is to evaluate the traffic crash history within the project limits to determine what, if any, existing highway safety concerns are present, and then identify how these safety concerns would be addressed by the proposed project using the design exception and by using full-design criteria. Refer to Publication 638, District Highway Safety Guidance Manual for information on the Highway Safety Manual (HSM) and evaluating the impact of changes in design elements on safety performance. Source: Pennsylvania Department of Transportation (PennDOT), Publication 10X (DM-1X); Appendix P–Design Exceptions, 2015.
It is the policy of the Department that all projects will be designed to meet the existing and future traffic needs in the most economical manner with emphasis on safety, operations, and maintainability. Particular attention with project design must be given to the controlling criteria for design. If any of the controlling design criteria cannot be met, a formal design exception is required. If the design exception involves features that are adequately addressed in the HSM, then the evaluation analysis and documentation shall (should/may) be completed using the methodologies described in the HSM.
To implement this policy the HSM shall (should/may) be used to evaluate the safety performance of a design modification to controlling design criteria. Documentation of the safety performance is key in addressing this policy for the design exception process. From a safety perspective, this documentation should examine contributing factors of crashes as well as the relationship between the roadway features being considered in the design exception and these contributing factors. The design exception documentation using the HSM is intended to discuss the safety performance of the full design feature versus the feature designed as indicated in the design exception.
The safety assessment included in the documentation shall include, at a minimum, a crash history, crash rates, and crash frequencies of the project location. The HSM is an excellent resource for evaluating the impact to safety performance of changes in the controlling design criteria. The HSM Part C predictive method and/or CMFs shall (should/may) be used in a comparative analysis of the predicted crash frequency with or without the proposed change in project design.
To support the safety performance evaluation, a number of commercially available products and tools developed by State DOTs or by the FHWA are available. The Interactive Highway Safety Design Model (IHSDM) and/or HSM spreadsheets are examples of available tools that can be used for the safety performance assessment. Also, Safety Performance Functions (SPF) and CMFs from the CMF Clearinghouse and/or State-specific CMFs developed by the Department can be used in the safety performance assessment.
Additionally, to document the economic assessment of the design change, chapter 7 of the HSM contains methods, including benefit/cost (B/C), net present value, and cost effectiveness, that can be used for the economic analysis documentation.
There are some specific areas within Operations and Maintenance where the HSM can be applied; however, there are limited specific examples that are available to develop sample policy or guidance language. Noteworthy examples along with sample language within each of the following areas are presented:
The objective of traffic operations activities is to optimize the performance of existing infrastructure through implementation of processes and projects to preserve capacity and address safety performance of the transportation system. This report focuses on integrating the HSM into two categories of traffic operations activities:
State and local transportation agencies are actively implementing intersection designs beyond the conventional signalized intersection or stop-controlled intersection. A few examples of these designs are roundabouts, diverging diamond interchanges, and continuous flow intersections. To address the need to provide an objective process to evaluate and select between intersection control alternatives, a number of State DOTs are developing Intersection Control Evaluation (ICE) policies and procedures. The goal of ICE is to provide a performance-based decisionmaking process, and the HSM is a valuable resource to complete the safety performance analysis within the ICE process. California, Georgia, Indiana, Minnesota, Washington, and Wisconsin all have developed ICE policies and procedures.
Specific to traffic signals, the Delaware Department of Transportation (DelDOT) Traffic Design Manual (2015) requires that a Traffic Signal Justification Study include an assessment of the safety implications of installing a new traffic signal, modifying an existing traffic signal, or removing an existing traffic signal.
Example Application: The Washington State Department of Transportation includes in its Intersection Control Analysis (ICA) an assessment of current conditions associated with the project location. A component of this assessment is an analysis of crash history using the HSM methodologies to determine the expected and predicted crash frequencies of the proposed intersection alternatives. Source: Washington State Department of Transportation (WSDOT), Engineering and Regional Operations Development Division, Design Office,"Design Manual, Chapter 1300" (M 22 01.12. November), 2015.
Example Language: Delaware Department of Transportation–A Traffic Signal Justification Study should include an assessment of the safety implications of installing a new traffic signal, modifying an existing traffic signal, or removing an existing traffic signal. The HSM should be consulted to assist in performing the safety assessment. DelDOT's preferred method for conducting the safety assessment is to use the"predictive method" from the HSM to estimate anticipated crash frequency. It is DelDOT's preference that a comparative analysis be performed using SPF's to compare the base (no improvements) scenario with the scenario that considers all proposed improvements. Additionally, the analyst should compare the SPF results with actual crash data, if available. Source: Delaware Department of Transportation,"Traffic Design Manual," 2015.
It is the policy of the Department to use the Intersection Control Evaluation (ICE) to assess intersection alternatives and according to the most recent adopted edition of the Manual on Uniform Traffic Control Devices (MUTCD). The ICE shall include an assessment of the safety performance of the intersection alternatives. The HSM shall (should/may) be used to assist in performing the safety assessment.
To implement this policy, when completing the ICE process, the HSM Part C predictive method and/or CMFs shall (should/may) be used to evaluate the safety performance of the proposed intersection projects and to provide better decisionmaking information for project selection and funding prioritization.
In addition, when considering operational changes such as signal timing or modifying intersections to include left-turn and/or right-right turn lanes or lighting upgrades, the HSM Part C predictive method and/or CMFs shall (should/may) be used to evaluate the safety performance of these modifications.
According to the Traffic Engineering Handbook, traffic impact analyses (TIA), also known as traffic impact studies, are widely used to estimate the travel impacts of new or expanded land development as part of the approvals process. (Institute of Traffic Engineers,"Traffic Engineering Handbook, Seventh Edition," January 2016, page 188.)
It is the policy of the Department that requests for roadway access connections include a traffic impact analysis (TIA). The TIA shall include a safety performance assessment. These analyses provide essential information for the decisionmaking process to evaluate the safety performance regarding changes to access the roadway system and the resulting traffic impacts. The HSM shall (should/may) be used to evaluate the safety performance associated with modifications to the roadway.
To implement this policy a traffic impact analysis shall be prepared for developments which desire access to the highway and shall include an assessment of traffic safety impact as a key component of the analysis. In this analysis, CMFs are a useful tool that shall (should/may) be used to estimate the anticipated safety impacts of the proposed roadway modifications.
In addition to the CMFs, the HSM Part C predictive method is a valuable tool in this assessment process and shall (should/may) be used to compare the safety performance with or without proposed modifications for access to the highway.
Preservation and maintenance is one of the final stages of the project development process. It is important for protecting the roadways investment and maintaining the existing transportation system in a state of good repair. Opportunities to implement the HSM methods include resurfacing, restoration, and rehabilitation (3R) projects and can include only resurfacing and/or restoration projects as well as maintenance activities. Some areas where the HSM can be used include geometric changes, shoulder and roadside improvements, traffic control, and guidance enhancement, and surface condition upgrades.
It is the policy of the Department that 3R projects are designed and constructed with due consideration of appropriate levels of traffic operations, safety, and maintenance. All 3R projects shall include an estimate of the safety benefits of the proposed treatments. The HSM shall (should/may) be used to estimate the safety impacts. The safety impacts of the treatment shall be included in the project documentation.
To implement this policy, when completing the safety assessment for the 3R project documentation and dependent on the scale of the project, the HSM Part C predictive method and/or CMFs shall (should/may) be used to evaluate the proposed project for funding.
In addition, if safety countermeasures are considered for inclusion in the 3R project, the HSM Part C predictive method and/or CMFs shall (should/may) be used to evaluate the safety performance of these countermeasures, and the results of the analysis shall be included in the project documentation.
Many if not all States have documented policies and procedures for implementing the Highway Safety Improvement Program (HSIP). These policies and procedures provide information on the State safety project selection and prioritization process, crash-cost estimates and benefit/cost analysis methodology (including project service life), and forms for applying for State HSIP funds. States also develop a variety of manuals for explaining how to conduct safety investigations that support the HSIP process. The roadway safety management process shown in figure 1 is the traditional approach taken to safety investigations. Methods in the HSM advance the roadway safety management process by providing quantifiable, repeatable, reliable results for each step in the roadway safety management process. Arizona, Illinois, Indiana, Minnesota, New Hampshire, Rhode Island, and Washington all have included HSM methods or software consistent with the HSM as part of their policy and procedures for HSIP management and implementation.
Figure 1. Chart. Roadway safety management process.
(Source: Cambridge Systematics, Inc.)
Example Application: The New Hampshire Department of Transportation (NHDOT) HSIP policy states that AASHTOWare Safety Analyst is used to prioritize HSIP projects and requires that cost effectiveness and expected reduction, in the form of a CMF or crash frequency, be tracked for all HSIP projects. Source: New Hampshire Department of Transportation,"Highway Safety Improvement Program: Manual and Guidance," December 2013.
Example Application: The Washington State Department of Transportation design manual states that the tools available for use in selecting recommended countermeasures include the HSM, AASHTOWare Safety Analyst, Road Safety Assessments (RSA), HSM prediction models, and the CMF Clearinghouse. Source: Washington State Department of Transportation, Engineering and Regional Operations Development Division, Design Office,"Design Manual, Chapter 321" (M22 01.12 November), 2015.
Example Application: The Rhode Island Department of Transportation (RIDOT) HSIP policy requires that the latest CMFs presented in the HSM and the CMF Clearinghouse be applied to estimate the expected safety benefits of various countermeasures. Source: Rhode Island Department of Transportation,"Planning, Implementation, and Program Effectiveness of Rhode Island's Highway Safety Improvement Program–Fiscal Year 2013." 2013.
Example Application: The Illinois Department of Transportation HSIP recommends the HSM Part C predictive method and CMFs as tools for evaluating safety projects. Illinois-specific safety performance functions (SPF) and calibration factors are available. Applicants must use benefit/cost analysis and CMFs from the HSM or the CMF Clearinghouse to demonstrate effectiveness of projects. Source: Illinois Department of Transportation, Highway Safety Improvement Program, 2015.
Example Application: The Indiana Department of Transportation (INDOT) HSIP guidance recommends a B/C ratio at or above 2.0 based on acceptable CMFs and an accurate total project cost estimate. In all cases, 1.0 is the minimum acceptable B/C ratio. Source: Indiana Department of Transportation."Highway Safety Improvement Program Local Project Selection Guidance," March 2013.
Example Application: The Arizona Department of Transportation (ADOT) HSIP policy indicates before-and-after studies of safety improvement projects compare various features and characteristics of the subject location before construction and after. Information derived from the evaluation process, such as reliable CMFs and an evaluation of the efficacy and benefits of projects, are critical to the planning process and to the success of the HSIP in Arizona. Source: Arizona Department of Transportation,"Highway Safety Improvement Program Manual," May 2015.
It is the policy of the Department to use HSM methods to quantify safety performance as part of the State roadway safety management process and HSIP process to reduce fatal and serious injury crashes.
To implement this policy, activities within the HSIP process shall include network screening, diagnosis and countermeasure selection, economic appraisal, predicted changes to crash frequency and severity, and project prioritization. The HSM shall (should/may) be used to evaluate safety performance in the following manner:
HSM chapter 4 – Network Screening methods shall (should/may) be used to prioritize sites for specified safety improvements. To the extent available data permit, a network screening performance measure that accounts for regression-to-the-mean bias shall (should/may) be used.
HSM chapter 5 – Diagnosis and chapter 6–Countermeasure selection shall (should/may) be used in the improvement evaluation process to study crash patterns and contributing factors and identify potential countermeasures to reduce crash frequency or severity. When project characteristics allow, the HSM Part C predictive method shall (should/may) be used to evaluate the safety impacts of alternatives under consideration. Anticipated changes in crash frequency and severity, as determined by the HSM Part C predictive method and/or CMFs, shall be used as a factor in project selection or prioritization.
HSM chapter 7 – Economic Appraisal provides methods that shall (should/may) be used for estimating economic impacts (benefits and costs) of alternative treatments and selecting or prioritizing improvements using benefit/cost (B/C), net present value, or cost effectiveness analysis.
HSM chapter 8 – Project Prioritization methods shall (should/may) be used within this programming process if considering implementation of countermeasures over a roadway system or with multiple locations.
HSM chapter 9 – Safety Effectiveness Evaluation shall (should/may) be used to evaluate the effectiveness of improvements implemented using HSIP funds.
The Department provides safety analysis tools that shall (should/may) be used for these evaluations. The tools are consistent with the principles and methodologies within the HSM. There are a number of commercially available products, products developed by States, and products developed by FHWA that can be used.
Although State DOTs have made good progress in implementing HSM concepts and methods within the safety management processes, expanding the reach of the HSM into other DOT processes such as planning and programming, project development, operations, and maintenance has been limited. To address an identified impediment to progress, the States participating in the HSM Implementation Pooled-Fund Study identified the need for a compilation and synthesis of existing State policies and development of sample policy and procedures language covering a range of activities in which use of the HSM would be beneficial.
The sample policy and procedures language is presented as an adaptation from noteworthy examples of existing language or applications in State DOT policies and manuals. Research for this informational report identified noteworthy State DOT examples covering a wide range of agency practices. These examples do not address all of the practices where the HSM could be used in the State DOTs, however. The sample language presented is based on processes for which some States already have language and/or processes or Pooled Fund Study States specifically requested sample language.
The sample policy language within this report provides State DOTs with an opportunity to develop policy language directing the use of the HSM in specific agency activities. To further this effort, the sample procedures language contains more descriptions, advice, and information of the HSM methodologies that State DOTs can use as a template for their own procedures documents.
For States in which the process of integrating the HSM into typical agency practices has been slower than desired, the information presented will provide a starting point that can accelerate efforts to develop and adopt policies and procedures to support implementation of the HSM. The sample language is intended to serve as a template that State DOT staff could adapt for use in their policies and manuals. State DOT staff can tailor the sample language to fit their agency's goals and objectives to expand implementation of the HSM.
| << Previous | Table of Contents | Next >> |
