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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Synthesis of Information Related to Highway Practices. Topic 56-19. Practices on Coordination of HSIP and Highway Safety Office Activities</title>
      <link>https://trid.trb.org/View/2384703</link>
      <description><![CDATA[The objective of this synthesis was to document how states coordinate HSIP and HSO management, practices, and associated funding in their processes, including program structure, planning, implementation, data sharing, evaluation, and reporting.]]></description>
      <pubDate>Fri, 31 May 2024 20:36:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2384703</guid>
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      <title>Development of a Methodology to Evaluate the Highway Safety Improvement Program</title>
      <link>https://trid.trb.org/View/2229001</link>
      <description><![CDATA[The goal of this research study was to provide information and develop tools that can help the Idaho Transportation Department (ITD) conduct safety effectiveness evaluation consistently across the state, provide data-driven rationale for future investments, and to help prepare the evaluation section of the Highway Safety Improvement Program (HSIP) Annual Report. A method and a geographic information system (GIS) tool were developed to evaluate the safety effectiveness of individual projects and groups of projects. The tool uses readily available data to calculate four safety performance measures: crash frequency, crash rate, annual economic cost, and severe crash proportion. The tool output includes: an Excel file with safety performance measure data; GIS files for mapping the crash data; and a report that provides tables and charts for the safety performance measures, a Google Street View image, and crash map. In the future, ITD could implement the process through a different platform, such a web application, or modify the GIS tool for future needs. A case study evaluation was done for nineteen HSIP projects that were completed between 2014 and 2016.]]></description>
      <pubDate>Mon, 28 Aug 2023 09:29:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2229001</guid>
    </item>
    <item>
      <title>Updating 2019 Safe Corridors Reports</title>
      <link>https://trid.trb.org/View/2205272</link>
      <description><![CDATA[NJDOT, in conjunction with the Division of State Police, is required to submit a Safe Corridors Program Assessment Report annually under N.J.S.A. 39:3-20.4. Therefore, there is a need to provide results of the safe corridor areas, as well as the highway safety projects and programs paid for by the fund, within the past year to the Senate Transportation Committee and the Assembly Transportation Committee, the President and minority leader of the Senate, and the Speaker and the minority leader of the General Assembly. This research was conducted in two phases. The first phase consisted of trend analysis for overall crashes within these designated areas, changes in fatal crashes and crash rates, and how that relates to the enforcement of stricter penalties associated with various traffic violations. The second phase provided an update to the selection methodology which is driven by Equivalent Property Damage Only (EPDO) values and crash thresholds. The selection process is based on prioritizing corridors with the highest crash costs, as well as crash thresholds consistent with various department priority lists and standards. The EPDO methodology is consistent with the grant program’s method for distributing funds to municipalities through which the corridors pass.]]></description>
      <pubDate>Tue, 01 Aug 2023 09:05:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2205272</guid>
    </item>
    <item>
      <title>Review of State DOT Practices for Analyzing the Effectiveness of Completed Highway Safety Improvement Projects</title>
      <link>https://trid.trb.org/View/2174259</link>
      <description><![CDATA[The South Dakota Department of Transportation (SDDOT) sought to enhance its safety program by investigating different methods of evaluating completed highway safety improvement projects. As a first step, the researcher completed a comprehensive literature review, using the results to develop a state survey. Upon approval of the state survey by the project’s technical panel, thirteen states representing various geographic locations and population distributions were interviewed to determine which evaluation methods they are currently using or have used in the past, what data is needed to employ each method, time constraints, staffing requirements, and what modifications, if any, they have made to any of the available methods. Next, the researcher interviewed employees from various offices within SDDOT and the Department of Public Safety to determine what resources and data elements are available to the traffic safety engineers for safety analysis. With the answers provided through the state surveys and interviews, the researcher recommended using the Empirical Bayes method of evaluating completed highway safety improvements when a particular safety improvement has been installed at multiple locations and simple before and after analysis for all other situations. The researcher also recommended making changes to the existing Geographic Information System (GIS) database and roadway database, making advanced GIS training available to safety engineers, and developing a simple investigations database to make safety effectiveness evaluations more efficient regardless of the evaluation technique used.]]></description>
      <pubDate>Tue, 23 May 2023 09:27:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2174259</guid>
    </item>
    <item>
      <title>Trends of Crash Mitigations at High Crash Intersections in Nevada, US Based on Highway Safety Improvement Program</title>
      <link>https://trid.trb.org/View/1972615</link>
      <description><![CDATA[This paper compared total trends of traffic crash frequency and severity at High Crash Location (HCL) intersections during three study periods in Nevada, US. The paper provided an in-depth inspection in selecting and ranking HCL intersections by the total score and Potential for Safety Improvement (PSI). The study indicates that the rank of HCL intersections by the total score is very different from ranks by PSIs. Intersections with high PSIs might not be qualified on the list of top-ranked HCL intersections with the underestimated attention, while intersections with low PSIs, but high total scores might be paid attention overestimated. The study reflected that potential rooms for crash mitigations are limited for intersections with negative PSIs but qualified as HCL intersections by the total score. How to select and rank HCL intersections plays a very important role in directing traffic safety funding allocation and most mitigating traffic crashes.]]></description>
      <pubDate>Fri, 21 Apr 2023 09:51:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1972615</guid>
    </item>
    <item>
      <title>NJDOT Highway Safety Improvement Program Implementation Plan</title>
      <link>https://trid.trb.org/View/2150893</link>
      <description><![CDATA[The New Jersey Department of Transportation Bureau of Safety, Bicycle & Pedestrian Programs (BSBPP) engaged Cambridge Systematics (CS) to assist with the development of the current Highway Safety Improvement Program Implementation Plan, which was a necessary document that BSBPP had to develop after not meeting their Federal safety performance measure targets. The development of this HSIP Implementation Plan was data-driven with safety stakeholder input, a review of New recent fatal and serious injury crashes, and historical HSIP program expenditures and performance. As a result of this analysis, New Jersey will dedicate HSIP funds in excess of $57.3 M for safety projects to address these deficiencies. Additionally, New Jersey identified several opportunities and actions to explore and advance in an effort to address challenges, such as aligning project development and safety investments with the New Jersey 2020 SHSP, increasing the development and implementation of HSIP-funded pedestrian and bicycle projects in underserved communities, conducting annual safety summits for relevant stakeholders, engaging MPO partners to develop Local Strategic Highway Safety Plans, and streamlining the Capital Delivery Process to HSIP projects. These actions will allow New Jersey to meet their Federal safety performance targets in subsequent years.]]></description>
      <pubDate>Mon, 17 Apr 2023 09:00:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/2150893</guid>
    </item>
    <item>
      <title>Evaluate the results of FHWA Safety Program Delivery implementation efforts</title>
      <link>https://trid.trb.org/View/2096546</link>
      <description><![CDATA[This research involves (1) performing program assessments, preparing annual reports, evaluating safety products and tools to identify gaps in existing safety efforts and opportunities for improvement; (2) identifying enhancements to the HSIP online reporting tool to address user needs and requirements, ultimately yielding annual outputs and outcomes on the HSIP program; (3) developing the 2020 HSIP National Summary Report to determine the aggregate number and type of projects funded under the HSIP and cost benefit ratio; (4) continuing a program evaluation project that helps to determine how States are modifying or enhancing their safety efforts based upon FHWA’s safety program delivery efforts; (5) insuring States have due process when FHWA takes an enforcement action; (6) instituting a sound process that enables States to submit additional supporting documentation that will help to validate or invalidate an action; (7) developing the 2019 HSIP National Summary Report to determine the aggregate number and type of projects funded under the HSIP; (8) developing a program evaluation project that helps to determine how States are modifying or enhancing their safety efforts based upon FHWA’s safety program delivery efforts.]]></description>
      <pubDate>Fri, 13 Jan 2023 14:49:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/2096546</guid>
    </item>
    <item>
      <title>Design MythBusters</title>
      <link>https://trid.trb.org/View/2047171</link>
      <description><![CDATA[When highway project designs depart from design values found in the Kentucky Transportation Cabinet (KYTC) Highway Design Manual and AASHTO’s A Policy on Geometric Design of Highways and Streets, project managers at the agency must obtain either a design exception or design variance. While designers are more comfortable with exceptions and variances than they were 10 or 20 years ago, some hesitancy remains, especially among the Cabinet’s consultants. Misperceptions about what exceptions or variances entail or about their performance may underlie this reluctance. Exceptions and variances are best conceptualized as formal justifications for design decisions. Project managers merely need to describe why a design does not adhere to published guidance and illustrate that safety and mobility performance are not significantly compromised — in every instance new designs offer improvement over existing conditions. The limited number of research studies on design exceptions have found no evidence to suggest facilities where exceptions have been used have worse safety performance than those which abide by typical design values. To encourage project managers and designers to embrace cost-effective, context-adapted designs — and the role of variances and exceptions play in delivering those solutions — this report presents design axioms and case studies that document projects on which exceptions and variances have been used with success. Most of the exceptions and variances used on these projects were minor (e.g., narrowing shoulders, reducing design speeds), were critical for addressing the stated purposes and needs, and resulted in a solution that blended the improved roadway with the surrounding contexts. Additional examples of mostly Highway Safety Improvement Program (HSIP) projects are catalogued that illustrate how creative fixes can be used to mitigate safety concerns.]]></description>
      <pubDate>Mon, 28 Nov 2022 10:56:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/2047171</guid>
    </item>
    <item>
      <title>Addressing Bicyclist Safety Through the Development of Crash Modification Factors for Bikeways</title>
      <link>https://trid.trb.org/View/2023867</link>
      <description><![CDATA[According to the Texas Department of Transportation Crash Record Information System database, there have been 26,148 crashes involving bicyclists (pedal cyclists) from 2010 to 2018 in Texas, resulting in 2,885 fatalities and suspected serious injuries and 22,937 non-incapacitating and possible injuries. Overall, bicycle crashes, as well as fatal and suspected serious injury crashes involving bicyclists, have been on the rise. Bicyclist safety concerns exist not only in cities and metropolitan areas but for the overall state highway network as well. In this project, the research team developed crash reduction factors for bikeway facilities implemented on Texas roadways to assess their safety and economic effectiveness. This research addressed the development of crash reduction factors for target crash types where sufficient bicycle facility information and crash information are available. To enable future cost-benefit assessments, the research included an estimate of the service life, installation, and maintenance costs of such facilities. The findings of this project indicate that installation of bikeway facilities can significantly improve safety for bicyclists. Implementing conventional bicycle lanes can help reduce total, fatal and injury, and property-damage-only crashes by 41–49 percent. Buffered bicycle lanes can improve safety by 20–65 percent, and separated bicycle lanes can improve safety by 41–53 percent. The economic benefits of these treatments were also found to be significantly higher than the estimated cost of installing them.]]></description>
      <pubDate>Fri, 30 Sep 2022 12:03:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2023867</guid>
    </item>
    <item>
      <title>Improving Passing Lane Safety and Efficiency</title>
      <link>https://trid.trb.org/View/2001656</link>
      <description><![CDATA[Field data collected in the passing lane sites shows several important characteristics. The speed in the right lane are consistently higher than the operating speed just upstream from the passing lane. Most importantly, and for both sites, the difference in average speed between vehicles in the right lane and left lane was lower than 3 mph at both locations along the passing zone. Such operations characteristics clearly show a need for intervention measure to slow traffic in the right lane to allow for a safer passing maneuvers. The crash analysis for 67 passing lanes segments identified a total of 137 crashes occurred either at the passing lane segments or at the merging areas downstream of the passing lane. The analysis covered a 10-year period from 2005 to 2015. Of these crashes, 46.15 percent were property damage crashes, 15.38 percent were possible injury crashes, 23.08 percent were visible injury crashes, 13.94 percent were serious injury crashes, and 1.45 percent were fatal crashes. Only 9 of the 137 crashes (6.57 percent) involved alcohol use. The majority of passing lane crashes occurred during clear weather conditions (62.04 percent) and during daylight (76.64 percent). Only 8.03 percent of the crashes occurred during ice/snow conditions. Speeding, improper lane-use, and improper overtaking were the major contribution factors in 84.67 of the crashes. The average crash rates (crash/million vehicle-mile/year) for merging segments, non-merging segments, and passing lane segments are 2.316, 2.228, and 2.271, respectively. While the merging segments, downstream of the passing lanes, have slightly higher crash rates than non-merging roadway segments (3.8 percent higher), the difference is not statistically significant at the 95% confidence level.]]></description>
      <pubDate>Wed, 24 Aug 2022 15:05:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2001656</guid>
    </item>
    <item>
      <title>WIS 75 Intersection Screening &amp; Project Development Process</title>
      <link>https://trid.trb.org/View/2003097</link>
      <description><![CDATA[This case study presents a safety analysis conducted by the Wisconsin Department of Transportation (WisDOT) at the intersection of State Highway 75 (WIS 75) and Plank Road (County Road A) in Racine County, WI. WisDOT proactively identified key safety needs early in the project development process and used a data-driven approach to evaluate the safety effects of potential alternatives. The corridor is scheduled for resurfacing in 2023, and through the network screening process, WisDOT identified an opportunity to develop a Highway Safety Improvement Program-related project in conjunction with routine maintenance. WisDOT’s diagnosis process reviewed recent crash history for potential contributing factors (e.g., driver behavior, sight distance, curvature, intersection geometry, etc.) and underscored the need to reduce failure-to-yield crashes. A preliminary intersection control evaluation eliminated infeasible alternatives early in the process and highlighted appropriate alternatives for further analysis. WisDOT applied State-calibrated safety performance functions in the Interactive Highway Safety Design Model software to predict crashes for each alternative and used State-approved crash modification factors where applicable. With these results, the economic appraisal step highlighted the most cost-effective alternative for this particular location. The State of the Practice methods and tools applied at each step in the process allowed WisDOT to thoroughly evaluate a safety need on its public road network as part of an institutional and readily repeatable planning process.]]></description>
      <pubDate>Wed, 24 Aug 2022 15:05:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/2003097</guid>
    </item>
    <item>
      <title>Practices for Balancing Safety Investments in a Comprehensive Safety Program</title>
      <link>https://trid.trb.org/View/1999317</link>
      <description><![CDATA[The Highway Safety Improvement Program (HSIP) provides federal aid to state departments of transportation (DOTs) for the purpose of significantly reducing traffic fatalities and serious injuries on public roads. Most DOTs use at least a portion of their HSIP funds on systemic safety improvement projects. However, variation exists in how DOTs prioritize projects and allocate funding across the various improvement types (i.e., spot, systemic, and systematic) to maximize safety benefits within their limited safety budgets. The Federal Highway Administration (FHWA) provides guidance to help DOTs determine the appropriate balance of investments between different project types. Because every phase of the HSIP may affect the safety performance of current and future projects, it is important to understand these variations and opportunities to improve on current practice. The objective of this synthesis is to document current DOT practices of identifying, prioritizing, and evaluating HSIP projects. Information for this study was gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected agencies. Four case examples provide additional information on the topic.]]></description>
      <pubDate>Sat, 30 Jul 2022 16:38:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/1999317</guid>
    </item>
    <item>
      <title>The Highway Safety Improvement Program: Paving the Road to a Safer Future</title>
      <link>https://trid.trb.org/View/1902125</link>
      <description><![CDATA[This article presents an overview of the US Federal Highway Administration's Highway Safety Improvement Program (HSIP) The HSIP, which sets the funding and policy tone for national safety implementation efforts, is a key place to begin advancing implementation of the Safe System Approach. The HSIP includes the States’ Strategic Highway Safety Plan (SHSP) and the program of highway safety improvement projects (or States’ HSIPs), as well as foundational elements of the HSIP that influence both program areas. In the informational report Integrating the Safe System Approach with the Highway Safety Improvement Program (FHWA-SA-20-018), the Federal Highway Administration identified opportunities and noteworthy practices to align the Safe System principles with the foundational elements of the HSIP, SHSPs, and states’ HSIPs.]]></description>
      <pubDate>Tue, 25 Jan 2022 09:50:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1902125</guid>
    </item>
    <item>
      <title>Safety and Economic Evaluation of the Highway Safety Improvement Program: Is there a Return on Investment?</title>
      <link>https://trid.trb.org/View/1905276</link>
      <description><![CDATA[The Highway Safety Improvement Program (HSIP) is a Federal-aid program aimed at achieving a significant reduction in traffic fatalities and serious injuries on all public roads. Projects are selected based on the potential reduction of severe crashes and the greatest return on investment. In this paper, a step-by-step process and methodology were developed to evaluate HSIP projects. The process and method were implemented to evaluate HSIP projects executed in Wisconsin between 2013 and 2019. Safety effectiveness evaluation and economic assessment were conducted using the Empirical Bayes (EB) method. Crash cost benefit of implemented projects was quantified to find the benefit–cost (B/C) for a horizon of 10?years and observed period of analysis. With data available from project evaluations, Crash Modification Factors (CMFs) for common treatments were developed. A total of 64 HSIP projects were evaluated. B/C ratios greater than one were observed in 43 projects. For a 10-year horizon, the aggregated B/C ratio was 2.71. Alternatively, using the observed data during the study period of each project, the observed overall crash cost benefit was equal to $72?million which corresponds to a B/C ratio of 1.10 (benefit already surpassed project costs at 3–5?years). Approximately 536 crashes were prevented which translates to seven lives saved, 380 injuries prevented, and avoided 1,067 property damage losses.]]></description>
      <pubDate>Mon, 24 Jan 2022 17:22:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1905276</guid>
    </item>
    <item>
      <title>Selecting Projects and Strategies to Maximize Highway Safety Improvement Program Performance</title>
      <link>https://trid.trb.org/View/1876151</link>
      <description><![CDATA[The Highway Safety Improvement Program (HSIP) is a core Federal-aid highway program with the purpose to achieve significant reductions in fatalities and serious injuries on all public roads. States implement the HSIP using various safety management approaches to identify, develop, prioritize, and select HSIP projects. State Departments of Transportation and metropolitan planning organizations set annual targets for safety performance using five Federally-required measures in terms of fatalities and serious injuries (23 CFR Part 409.209). Meeting or exceeding safety performance targets is not a certainty, but a potential based on the predicted performance and potential range of effectiveness of the HSIP as well as external factors. Agencies can help improve safety performance by increasing funding for highway safety projects and by choosing locations with high potential for safety improvement along with countermeasures that offer the greatest reductions in fatalities and serious injuries per dollar invested. Employing sound safety management approaches (i.e., site-specific, systemic, and systematic), economic measures (benefit-cost ratio for fatal and serious-injury crashes), implementation strategies, and professional judgment to increase the predicted safety performance of the HSIP increases the potential that a State maximizes its HSIP performance. While this guide focuses on the HSIP, the methods are applicable to other infrastructure and non-infrastructure programs]]></description>
      <pubDate>Wed, 22 Sep 2021 12:04:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1876151</guid>
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