Practices for Balancing Safety Investments in a Comprehensive Safety Program (2022)

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65   This chapter provides a summary of the synthesis findings as well as gaps in current practice and opportunities to overcome these gaps through future research, technical assistance, and training. Summary This synthesis effort documents current state DOT practices for identifying, prioritizing, and evaluating HSIP projects. The study employed a multifaceted approach to document state DOT practices, including (a) a literature review, (b) a survey of state HSIP practices, and (c) a series of interviews with state DOT personnel. The literature review included a review of 36 state HSIP and Safety Program manuals along with other federal and state resources that describe methods to identify, prioritize, and evaluate HSIP projects. The survey of state DOTs consisted of 24 questions and was sent to the HSIP annual report contact person in all 50 states, the District of Columbia, and Puerto Rico. A total of 42 state DOTs (40 states, the District of Columbia, and Puerto Rico) responded. In-depth interviews focused on select state DOTs to serve as case examples in the synthesis. The project team selected four state DOTs (Maine, North Carolina, Oregon, and Pennsylvania) based on the results of the literature review and survey to solicit details on specific aspects of HSIP project identification, prioritization, and evaluation. The results of the literature review and survey are consistent, which helps to validate the infor- mation obtained from both sources. The following sections highlight key takeaways related to each area (project identification, prioritization, and evaluation). Project Identification • The process to identify, prioritize, and evaluate spot HSIP projects is fairly well established, as evidenced by the HSIP documentation in most state DOTs. • There are fewer state DOTs with a documented approach to systemic HSIP projects. • A limited number of state HSIP manuals include a documented approach on how to identify systematic projects. • Traditional network screening performance measures (e.g., crash frequency and crash rate) are most common for spot projects, but there are several state DOTs that have implemented more rigorous and contemporary methods from the HSM (e.g., LOSS, excess predicted, expected, and excess expected crashes). • Systemic methods range from basic to advanced, with the majority of state DOTs using more basic approaches to systemic analysis. • Nearly all state DOTs use more in-depth investigations to diagnose the crash patterns and underlying crash contributing factors, particularly for potential spot project locations. C H A P T E R 5 Summary of Findings

66 Practices for Balancing Safety Investments in a Comprehensive Safety Program • Diagnostic methods for spot locations range from basic crash summaries and collision dia- grams to the tests of proportions and multidisciplinary site investigation teams. • Some state DOTs provide further guidance and resources for countermeasure selection, including an approved list of countermeasures and a list of applicable CMFs for use in benefit- cost analysis. • For both spot and systemic approaches, most state DOTs use the same method to identify potential projects on state and local roads. • Many state DOTs supplement quantitative approaches with qualitative input from stake- holders (e.g., public inputs, police requests, or observations by district or regional staff) to identify potential project locations. Project Prioritization • The most common quantitative approach to project prioritization is the benefit-cost ratio. • Most state DOTs that compute the benefit-cost ratio base the estimate on expected reductions in total crashes. • Some state DOTs use variations, such as benefits based on expected reductions in fatal and serious injury crashes. • Many state DOTs incorporate one or more qualitative or non-crash-based factors to prioritize projects. • Some state DOTs prioritize all candidate projects together, and some have set-aside funding for state and local projects, spot and systemic projects, or specific emphasis areas (e.g., road- way departure, intersection, pedestrian, bicycle). • Some state DOTs split funding between spot and systemic projects or state and local projects, but few of the reviewed state DOTs have a formula to allocate funding between these projects. • The most common quantitative approaches to allocating funding are based on the distribu- tion of fatal and serious injury crashes. • Other state DOTs have established funding allocation goals based on qualitative assessments and professional judgment. Project Evaluation • State DOT guidance on project evaluations ranges from detailed procedures to acknowledg- ment of an evaluation process to no reference of evaluations at all. • The simple before–after study design without traffic volume correction is the most common project evaluation method. • Relatively few state DOTs use anything more rigorous for project-level evaluations. • Some state DOTs use more reliable methods to develop CMFs based on countermeasure-level evaluations. • State DOTs typically evaluate all projects in a similar framework regardless of how the projects are identified or prioritized (e.g., spot versus systemic or state versus local road). Gaps Based on the results of the synthesis, there are apparent gaps related to methods, data, and project implementation. The following sections discuss each of these three categories. Gaps in Methods There are gaps in methods throughout the process to identify, prioritize, and evaluate HSIP projects. For spot projects, the basic network screening performance measures (e.g., crash frequency

Summary of Findings 67   and crash rate) are most common. Similarly, for systemic projects, the basic methods (e.g., sum- mary statistics and crash trees) are most common. By using more reliable methods to identify sites with potential for safety improvement and to confirm the underlying crash contributing factors and risk factors, there is an opportunity to better target investments and improve the effectiveness of the HSIP. This gap also relates to countermeasure selection and economic analysis. Many state DOTs are using CMFs to support these steps, but the methods are based on observed crash history in many state DOTs. There is a need to expand the use of the predictive method. There is also a need to expand the use of the predictive method for systemic projects. It was clear from the synthesis results that more state DOTs quantify the expected safety benefits for spot projects compared to systemic projects. Gaps in Data Some of the gaps in methods discussed previously are related to gaps in data. For example, as opposed to the more traditional network screening performance measures (e.g., crash fre- quency) that only require crash data, the more reliable network screening performance mea- sures (e.g., expected or excess expected crashes) require more data (2). This is a particular gap for local roads where some state DOTs noted differences in practice because of differences in data availability and quality on state and local roads. Gaps in Project Implementation One of the areas the survey tried to uncover was efficiencies in the project development and implementation process. A majority of state DOTs do not allow for shortcuts when imple- menting spot or systemic HSIP projects. Others allow for some efficiencies, such as stream- lining the typical project planning and development process for certain safety projects or purchasing products to be installed by public agency forces, which is more cost-effective and timelier than letting projects to bid for construction. Although relatively few examples of effi- ciencies were uncovered, this was mentioned by several state DOTs during the interviews as an area of need. For instance, Pennsylvania noted that one challenge has been implementing projects on the local system due to the level of effort needed to apply for and manage federal- aid highway projects. Future Research Following the discussion of apparent gaps, this section describes opportunities for future research related to methods, data, and project implementation. Future Research in Methods There is an opportunity to further demonstrate the value of using more reliable methods throughout the HSIP process. There are a few select resources on this topic (2, 23–27), but there is the potential to continue to show the differences between traditional and rigorous methods. Several state DOTs have implemented more rigorous and contemporary methods from the HSM (e.g., LOSS, excess predicted, expected, and excess expected crashes) in network screening. These state DOTs could serve as the basis for case studies to demonstrate the differences in state DOT practices and the change/improvement in the overall effectiveness of the HSIP. The related research could investigate the change in benefit-cost over time as agencies transitioned from tra- ditional to more reliable methods.

68 Practices for Balancing Safety Investments in a Comprehensive Safety Program Specific to the systemic approach, there is an opportunity to advance the state-of-the-practice on risk factor identification and project prioritization. For example, many state DOTs are using basic risk-based analysis methods, such as crash summaries and crash trees, to identify and assess potential risk factors, and there is an opportunity to advance the practice to either use more rigorous methods to analyze state-specific data or apply the results from reputable national research, including NCHRP Research Report 955: Guide for Quantitative Approaches to Systemic Safety Analysis (28). With respect to funding allocation, there is an opportunity to investigate the relative strengths and limitations of different options. Although there are a variety of existing methods for allo- cating funding among project types and initiatives, few are based on a documented process. It would be useful to know if certain funding allocation methods result in a more effective or efficient return on investment and then share the results with the state DOTs. Related to the application of CMFs in countermeasure selection and economic analysis, there is an opportunity to increase the use of the predictive method, including the use of SPFs and CMFs. Some clarification is needed on when to use crash history, SPFs, CMFs, or combi- nations. Although this is documented in FHWA’s guide, Scale and Scope of Safety Assessment Methods in the Project Development Process (29), there is an apparent lack of implementation. As such, there may be a need to further market existing resources related to the use of the pre- dictive method and other reliable methods for identifying and prioritizing countermeasures and projects. There is also an opportunity to develop guidance or training on how to estimate the expected safety benefits of systemic improvements, as many of the current resources focus on the spot approach. Future Research in Data Data improvements are a work in progress. MAP-21 and the FAST Act required the Secretary to establish a subset of the Model Inventory of Roadway Elements (MIRE) that are useful for roadway safety analysis [23 U.S.C. 148(f)(2)]. FHWA established the MIRE fundamental data elements (FDEs) as part of the HSIP Final Rule changes to 23 CFR Part 924, effective April 14, 2016. All state DOTs are required to collect the MIRE FDEs on all state, local, and tribal roads by September 30, 2026. With these efforts, the state DOTs should have the data required to employ more reliable methods. Other related challenges may be related to data quality and maintaining the data set over time. In addition, there will be a need to provide access to the data set for those that need to use it for safety management purposes. Future Research in Project Implementation There are opportunities to develop case studies and noteworthy practices on how to improve project implementation. Local projects are typically lower cost, and it can be more efficient to select higher-cost projects, bundle smaller projects, or utilize indefinite delivery, indefinite quan- tity (IDIQ) contract mechanisms to gain efficiencies during project delivery. This helps to ensure that most of the budget is spent on implementing countermeasures as opposed to project management. FHWA’s Every Day Counts Round 5 includes a project bundling initiative; however, future research could include factors related to timeliness, cost overruns, and proj- ect implementation on local roads. FHWA published an interim final rule in November 2020 to allow state DOTs to use IDIQ contracting methods, including job order contracting, on federal-aid highway projects under certain circumstances on a permanent basis (30). There is an opportunity for state DOTs to implement this contracting mechanism to expedite project delivery, increase administrative efficiency, reduce project costs, and increase flexibility in the use federal-aid funds on certain projects (30).