Vegetation and roadside safety features need to be strong in order to prevent erosion that can lead to pavement or bridge failure as the ground supporting the overall structure erodes.
NCHRP Research Report 1155: Tools and Technology for Roadside Vegetation Asset Management: A Guide, from TRB's National Cooperative Highway Research Program, describes how state departments of transportation (DOTs) can promote and implement roadside vegetation asset management (RVAM). The guide offers suggestions, including support for promoting and updating RVAM plans and information on tools and technology that can serve state DOTs during RVAM tasks.
Supplemental to the report is NCHRP Web-Only Document 429: Investigation of Tools and Technology for Roadside Vegetation Asset Management.
102 pages
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ISBN Paperback: 0-309-59939-3
ISBN Ebook: 0-309-59940-7
DOI:
https://doi.org/10.17226/29247
National Academies of Sciences, Engineering, and Medicine. 2025. Tools and Technology for Roadside Vegetation Asset Management: A Guide. Washington, DC: The National Academies Press.
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In today’s rapidly evolving environment, state transportation agencies frequently face challenges that require specific organizational capabilities. In 2019, the National Cooperative Highway Research Program developed the Agency Capability Building (ACB) Portal, which presents a framework, supporting tools, and resources for enhancing transportation capacity.
NCHRP Web-Only Document 439: Implementing the Agency Capability Building Framework to Activate Organizational Change documents the activities, participants, data collected, and lessons learned from an effort designed to facilitate the use of the ACB by transportation agencies. The report also includes linked resources and appendices that represent key products of the research.
54 pages
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8.5 x 11
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ISBN Ebook: 0-309-60201-7
DOI:
https://doi.org/10.17226/29324
National Academies of Sciences, Engineering, and Medicine. 2025. Implementing the Agency Capability Building Framework to Activate Organizational Change. Washington, DC: The National Academies Press.
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NCHRP Web-Only Document 425: Development of the Human Factors Guidelines for Road Systems, Third Edition is supplemental to and documents the research objectives, methods, and results of NCHRP Research Report 1148: Human Factors Guidelines for Road Systems, Third Edition.
32 pages
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ISBN Ebook: 0-309-99390-3
DOI:
https://doi.org/10.17226/29159
National Academies of Sciences, Engineering, and Medicine. 2025. Development of the Human Factors Guidelines for Road Systems: Third Edition. Washington, DC: The National Academies Press.
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NCHRP Research Report 1148: Human Factors Guidelines for Road Systems, Third Edition, from TRB's National Cooperative Highway Research Program, presents updated guidelines for integrating human factors (HF) principles into the planning, design, construction, and operation of roadway systems. The guidelines build on previous editions of Human Factors Guidelines for Road Systems.
Supplemental to the report is NCHRP Web-Only Document 425: Development of the Human Factors Guidelines for Road Systems, Third Edition.
492 pages
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paperback
ISBN Paperback: 0-309-99386-5
ISBN Ebook: 0-309-99387-3
DOI:
https://doi.org/10.17226/29158
National Academies of Sciences, Engineering, and Medicine. 2025. Human Factors Guidelines for Road Systems: Third Edition. Washington, DC: The National Academies Press.
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The majority of bridges built in the United States utilize concrete bridge elements with prestressed uncoated steel strands that are susceptible to corrosion, leading to structure deterioration. Delaying strand corrosion will reduce maintenance needs, extend bridge service life, and enhance safety.
NCHRP Research Report 1161: Stainless Steel Strands for Prestressed Concrete Bridge Elements, from TRB's National Cooperative Highway Research Program, presents state-of-the-art guidelines to assist state departments of transportation (DOTs) in the applications of stainless steel strands for prestressed concrete bridge elements.
94 pages
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paperback
ISBN Paperback: 0-309-59931-8
ISBN Ebook: 0-309-59932-6
DOI:
https://doi.org/10.17226/29245
National Academies of Sciences, Engineering, and Medicine. 2025. Stainless Steel Strands for Prestressed Concrete Bridge Elements. Washington, DC: The National Academies Press.
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Transportation agencies, including state departments of transportation (DOTs), are increasing their focus on resilience as they continue to manage the impacts of extreme weather and natural hazard variability on transportation infrastructure and communities that rely on them to sustain and improve their quality of life. To enable evaluation and an eventual transition to a performance-based planning and implementation approach for investing in resilience, agencies need approaches and tools to track the efficacy of resilience initiatives, projects, and investments.
NCHRP Web-Only Document 432: Impacts and Performance of State DOT Resilience Efforts, from TRB's National Cooperative Highway Research Program, is supplemental to NCHRP Research Report 1159: Measuring Impacts and Performance of State DOT Resilience Efforts: A Guide.
105 pages
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8.5 x 11
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ISBN Ebook: 0-309-99487-X
DOI:
https://doi.org/10.17226/29208
National Academies of Sciences, Engineering, and Medicine. 2025. Impacts and Performance of State DOT Resilience Efforts. Washington, DC: The National Academies Press.
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State departments of transportation (DOTs) have increased their focus on resilience initiatives to address impacts from short-term and long-term stressors such as extreme weather events, wildfires, and flooding. Economic shifts, changes in population, and other disruptions also cause transportation agencies to modify their practices to accommodate uncertainty. State DOTs need tools and approaches to justify additional project expenses for increasing resilience.
NCHRP Research Report 1159: Measuring Impacts and Performance of State DOT Resilience Efforts: A Guide, from TRB's National Cooperative Highway Research Program, presents a guide for applying resilience performance measures (RPMs) to resilience investments made by state DOTs.
Supplemental to the report is NCHRP Web-Only Document 432: Impacts and Performance of State DOT Resilience Efforts.
76 pages
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paperback
ISBN Paperback: 0-309-99479-9
ISBN Ebook: 0-309-99480-2
DOI:
https://doi.org/10.17226/29207
National Academies of Sciences, Engineering, and Medicine. 2025. Measuring Impacts and Performance of State DOT Resilience Efforts: A Guide. Washington, DC: The National Academies Press.
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The Census Transportation Planning Products datasets and the American Community Survey are critical data elements that support the analysis of transportation plans, policies, programs, and project selection.
NCHRP Research Report 1108: Census Data Field Guide for Transportation Applications, from TRB's National Cooperative Highway Research Program, presents a comprehensive field guide for transportation practitioners on how to effectively utilize census data to support transportation analyses.
136 pages
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paperback
ISBN Paperback: 0-309-73399-5
ISBN Ebook: 0-309-73400-2
DOI:
https://doi.org/10.17226/29028
National Academies of Sciences, Engineering, and Medicine. 2025. Census Data Field Guide for Transportation Applications. Washington, DC: The National Academies Press.
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Pedestrian fatalities in the U.S. have increased dramatically since 2010, with most of the rise occurring in dark conditions.
NCHRP Web-Only Document 430: Improving Pedestrian Safety at Night, from TRB's National Cooperative Highway Research Program, is supplemental to NCHRP Research Report 1157: Strategies to Improve Pedestrian Safety at Night: A Guide and summarizes the research from previous portions of this multiphase project.
197 pages
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ISBN Ebook: 0-309-99560-4
DOI:
https://doi.org/10.17226/29225
National Academies of Sciences, Engineering, and Medicine. 2025. Improving Pedestrian Safety at Night. Washington, DC: The National Academies Press.
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Walking is an important part of a healthy, sustainable transportation system. Yet walking is too often inaccessible, uncomfortable, or unsafe as a practical option for large numbers of people because of traffic risk, discomfort, or inconvenience. Multilane roadways, higher design and posted speeds, and a lack of safe and convenient pedestrian walking and crossing facilities and operations, even at known attractors such as bus stops and grocery stores, are consistently associated with pedestrian fatalities in the United States. The risk is much higher at night. Between 2018 and 2022, 76% of U.S. pedestrian crash fatalities occurred in darkness.
NCHRP Research Report 1157: Strategies to Improve Pedestrian Safety at Night: A Guide, from TRB's National Cooperative Highway Research Program, is a state-of-the-art resource for state departments of transportation on addressing the high pedestrian fatalities on their roadways, especially at night. The guide features strategies for transportation professionals to implement to directly enhance pedestrian safety at night and was informed by a multimethod study of pedestrian safety in darkness in the United States.
Supplemental to the report is NCHRP Web-Only Document 430: Improving Pedestrian Safety at Night.
80 pages
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paperback
ISBN Paperback: 0-309-99555-8
ISBN Ebook: 0-309-99556-6
DOI:
https://doi.org/10.17226/29224
National Academies of Sciences, Engineering, and Medicine. 2025. Strategies to Improve Pedestrian Safety at Night: A Guide. Washington, DC: The National Academies Press.
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Full-depth reclamation (FDR) is a method to recycle in-place asphalt material for reconstruction and rehabilitation of flexible pavements.
NCHRP Synthesis 657: Full-Depth Reclamation: Current Practices, from TRB's National Cooperative Highway Research Program, documents practices used by state departments of transportation, including classification of FDR types, site selection, specifications and guidelines for FDR mix design, and test methods to evaluate FDR quality.
146 pages
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paperback
ISBN Paperback: 0-309-99545-0
ISBN Ebook: 0-309-99546-9
DOI:
https://doi.org/10.17226/29222
National Academies of Sciences, Engineering, and Medicine. 2025. Full-Depth Reclamation: Current Practices. Washington, DC: The National Academies Press.
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Transportation leaders encounter multiple situations daily that require decisions to be made. These decisions can have impacts on billions of dollars or an entire state of travelers, and they often need to be made quickly and without all the information available.
NCHRP Research Report 1162: Advancing the Art and Science of Decision-Making: A Guide, from TRB’s National Cooperative Highway Research Program, combines practical advice and experiences from transportation agency executives with the latest findings from cognitive science research to supplement leaders’ toolboxes for good decision-making.
87 pages
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paperback
ISBN Paperback: 0-309-60018-9
ISBN Ebook: 0-309-60016-2
DOI:
https://doi.org/10.17226/29265
National Academies of Sciences, Engineering, and Medicine. 2025. Advancing the Art and Science of Decision-Making: A Guide. Washington, DC: The National Academies Press.
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The transportation industry continues to face a range of unforeseen and evolving challenges to transportation assets and operations that affect the performance and resilience of transportation systems and networks. For example, significant disruptions to supply chains and traffic patterns were outcomes of the unanticipated collapse of the Key Bridge in Baltimore, Maryland.
NCHRP Research Report 1146: Risk Management at State DOTs: Building Momentum and Sustaining the Practice, from TRB's National Cooperative Highway Research Program, provides guidelines for state departments of transportation and other agencies to establish and maintain a risk management culture and practice.
104 pages
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paperback
ISBN Paperback: 0-309-99340-7
ISBN Ebook: 0-309-99341-5
DOI:
https://doi.org/10.17226/29144
National Academies of Sciences, Engineering, and Medicine. 2025. Risk Management at State DOTs: Building Momentum and Sustaining the Practice. Washington, DC: The National Academies Press.
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The availability of large-scale, high-resolution, and consistently collected road data will improve the safety of all road users. The use of artificial intelligence (AI), machine learning (ML), and big data is key in providing the information needed to power data-driven, public, and proprietary safety analysis tools, as well as predictive and other systemic safety tools.
NCHRP Research Report 1152: Leveraging Artificial Intelligence and Big Data to Enhance Safety Analysis: A Guide, a publication from TRB's National Cooperative Highway Research Program, outlines the limitations of traditional safety evaluations and demonstrates how new data sources— like connected vehicles, LiDAR, video analytics, and edge devices—can enhance safety insights and predictive capabilities. Case studies include successful pilots with the Oregon Department of Transportation, showcasing ML models for inventorying streetlight luminaires to inform crash risk analysis, and the City of Bellevue, WA, analyzing vehicle turning behavior to improve safety at signalized intersections.
110 pages
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paperback
ISBN Paperback: 0-309-59960-1
ISBN Ebook: 0-309-59961-X
DOI:
https://doi.org/10.17226/29098
National Academies of Sciences, Engineering, and Medicine. 2025. Leveraging Artificial Intelligence and Big Data to Enhance Safety Analysis: A Guide. Washington, DC: The National Academies Press.
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Recent years have seen an increased focus on the performance of roadside hardware. As the use of high-tension cable barrier (HTCB) systems increased across the United States, the transportation industry determined that there was a research need to summarize the state of practice for HTCB systems.
NCHRP Research Report 1156: Material Requirements for High-Tension Cable Barriers: A Guide, from TRB's National Cooperative Highway Research Program, presents a guide on material requirements for highway guardrail systems and their components to provide consistency with current roadside safety hardware requirements.
The report follows up on NCHRP Research Report 1020: Investigation of Material Requirements for Highway Guardrail Systems.
150 pages
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paperback
ISBN Paperback: 0-309-99428-4
ISBN Ebook: 0-309-99429-2
DOI:
https://doi.org/10.17226/29173
National Academies of Sciences, Engineering, and Medicine. 2025. Material Requirements for High-Tension Cable Barriers: A Guide. Washington, DC: The National Academies Press.
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The Federal Communications Commission’s current licensing freeze, while it considers new rules for the 4.9 GHz spectrum band, leaves a limited number of options for new use of the band. While it is not presently known when the freeze will be lifted, and if any new rules will be put into effect, there are nevertheless currently several potential opportunities for state department of transportation operations in the band.
NCHRP Web-Only Document 422: Planning for 4.9 GHz Spectrum Changes, from TRB's National Cooperative Highway Research Program, provides background and guidance for transportation agencies that wish to implement systems in the band.
16 pages
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ISBN Ebook: 0-309-59969-5
DOI:
https://doi.org/10.17226/29256
National Academies of Sciences, Engineering, and Medicine. 2025. Planning for 4.9 GHz Spectrum Changes. Washington, DC: The National Academies Press.
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State departments of transportation (DOTs) have begun changing the medium of construction contract documents from paper or 2D plans to 3D models that are contractually binding. The driver of this major change is the ability for contractors and inspectors to use 3D models directly to support project activities and communicate the design intent. However, changing the medium of construction contract documents has created challenges for state DOTs, including a need for robust review and documentation procedures as well as a lack of automated quality control and quality assurance management processes for 3D models.
NCHRP Research Report 1153: Digital Model–Based Project Development and Delivery: A Guide for Quality Management, from TRB’s National Cooperative Highway Research Program, presents state-of-the-art information to assist state DOTs in their review of 3D models that are contractually binding and to advance the use of digital project development and delivery.
Supplemental to the report are NCHRP Web-Only Document 428: Quality Management for Digital Model–Based Project Development and Delivery, Appendix F Addendum: Review Checklist Spreadsheet, an implementation plan, and a webinar presentation.
106 pages
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8.5 x 11
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paperback
ISBN Paperback: 0-309-99422-5
ISBN Ebook: 0-309-99423-3
DOI:
https://doi.org/10.17226/29171
National Academies of Sciences, Engineering, and Medicine. 2025. Digital Model–Based Project Development and Delivery: A Guide for Quality Management. Washington, DC: The National Academies Press.
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NCHRP Web-Only Document 428: Quality Management for Digital Model–Based Project Development and Delivery, from TRB’s National Cooperative Highway Research Program, addresses two key challenges for state departments of transportation and other highway agencies: the use of 3D models as a new way to review construction designs and the review of the 3D models themselves.
The document is supplemental to NCHRP Research Report 1153: Digital Model–Based Project Development and Delivery: A Guide for Quality Management.
150 pages
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8.5 x 11
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ISBN Ebook: 0-309-99426-8
DOI:
https://doi.org/10.17226/29172
National Academies of Sciences, Engineering, and Medicine. 2025. Quality Management for Digital Model–Based Project Development and Delivery. Washington, DC: The National Academies Press.
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