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Long Freight Trains: Ensuring Safe Operations, Mitigating Adverse Impacts
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Consensus and Advisory Studies Division Committee on the Impact of Trains Longer Than 7,500 FeetLonger trains have more cars, possibly a greater variety of car types and sizes, and more requirements for power distributed across the train in comparison with shorter manifest trains. Because of this and other factors, the Federal Railroad Administration (FRA) should revise the Risk Reduction Program (RRP) rule to require railroads to address all major operational changes in their RRPs in an explicit and comprehensive manner. TRB Special Report 353: Long Freight Trains: Ensuring Safe Operation, Mitigating Adverse Impacts, from the Transportation Research Board of the National Academies of Sciences, Engineering, and Medicine, examines in response to a request from the U.S. Congress the safety challenges arising from the operation of longer freight trains, and particularly from the increased use of longer manifest trains that transport a mix of freight in many different types of railcars. The report makes several other recommendations to FRA and also examines issues such as the impact of increasing freight train length on the frequency and duration of blocked highway-rail grade crossings and the scheduling and efficient operations of Amtrak intercity passenger trains.
Management Practices for Ancillary Transportation Assets
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Chris Harper National Cooperative Highway Research Program Omar Smadi Dan Tran Roy SturgillRecognizing the value of managing a broader range of assets beyond pavements and bridges, many state departments of transportation (DOTs) are developing dynamic inventories of various ancillary assets in their Transportation Asset Management Plans. Examples include hydraulic structures like culverts and drainage systems and overhead sign and signal structures and signal systems. NCHRP Synthesis 647: Management Practices for Ancillary Transportation Assets, from TRB’s National Cooperative Highway Research Program, documents how state DOTs manage ancillary transportation assets, including those managed via performance-based approaches.
Methods of Airport Arts Program Management
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Airport Cooperative Research Program Holli Kreinbring Melissa L. NemonAirport arts programs benefit passengers, stakeholders, and airports by displaying visually appealing exhibits through the airport journey that can highlight the airport and provide cultural education about the area. ACRP Synthesis 135: Methods of Airport Arts Program Management, from TRB's Airport Cooperative Research Program, describes management methods that airports and their arts program administrators use to implement, operate, and manage their programs.
Microtransit Solutions in Rural Communities: On-Demand Alternatives to Dial-a-Ride Services and Unproductive Coverage Routes
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Transit Cooperative Research Program Laura Duke Jessica Klion Alanna McKeemanDial-a-ride and fixed-route transit options are some of the ways that microtransit services have traditionally been implemented in rural areas. App-based booking and dynamic routing are among the newer offerings transit agencies are exploring to provide greater flexibility and more spontaneous options for users. TCRP Synthesis 178: Microtransit Solutions in Rural Communities: On-Demand Alternatives to Dial-a-Ride Services and Unproductive Coverage Routes, from TRB’s Transit Cooperative Research Program, provides a comprehensive overview of rural microtransit operations through a literature review, surveys of 19 transit providers, and case examples of seven agencies. High customer satisfaction and improved service efficiency were frequently cited as benefits of microtransit solutions.
Minimizing Utility Issues During Construction: A Guide
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine National Cooperative Highway Research Program Jesse Cooper Harshit Shukla Jenny Naranjo Cesar QuirogaRoadways intersect utility facilities above and below ground. Facilities such as water, sewer, natural gas, fiber optic, and electric lines may be impacted by highway improvement projects and often require relocation. Issues and conflicts between highway features and utility facilities can arise and impede highway construction projects, causing construction delays, economic impacts, and safety concerns. NCHRP Research Report 1110: Minimizing Utility Issues During Construction: A Guide, from TRB’s National Cooperative Highway Research Program, provides practitioners with a guide to help mitigate utility conflicts using strategies such as improving pre-letting utility investigations, inspection procedures, and change order documentation. Supplemental to the report is NCHRP Web-Only Document 396: Strategies to Address Utility Issues During Highway Construction, a presentation, and an implementation plan.
Mitigating Exposure to Airborne Diseases for Public Transportation Passengers and Employees: Executive Summary
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Kevin Dover National Cooperative Highway Research Program Transit Cooperative Research Program Anne Kerber Jacob Swanson Brenda Lopez Heejung JungThe COVID-19 pandemic highlighted the critical need for advanced aircontrol measures to prevent the spread of airborne diseases. Public transportation vehicles, especially buses, can be high-risk environments for both passengers and employees. Mitigating Exposure to Airborne Diseases for Public Transportation Passengers and Employees: Executive Summary, a joint publication from TRB’s Transit Cooperative Research Program and National Cooperative Highway Research Program, aims to provide public transportation agencies with practical strategies to reduce the risk of airborne disease transmission, safeguarding the health and well-being of both employees and passengers. Supplemental to the report is TCRP Web-Only Document 78/NCHRP Web-Only Document 410: Protecting Transportation Employees and the Traveling Public from Airborne Diseases.
Mobile Devices as a Tool for Digitized Project Documentation and Inspection
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine National Cooperative Highway Research Program Ryan Grith Gabriel Dadi Nisa Zahin Bassam Ramadan Hala NassereddineConsumer-grade mobile devices including smartphones, tablets, peripheral devices, and Rovers?are increasingly used as innovative tools in construction project delivery, documentation, and inspection. Advances in camera technology combined with increased accuracy in geolocation, graphical displays, and LiDAR abilities provide a powerful construction technology that is also widely accessible and used by most construction professionals on jobsites. NCHRP Synthesis 635: Mobile Devices as a Tool for Digitized Project Documentation and Inspection, from TRB’s National Cooperative Highway Research Program, documents practices of state departments of transportation for using mobile devices to support digitized project delivery, documentation, and inspection.
Modern Solutions to Safe and Efficient Work Zone Travel
by Transportation Research Board Sarah Robinson National Academies of Sciences, Engineering, and Medicine Michael Fontaine Stephanie Baker National Cooperative Highway Research Program Tammy Trimble Paul Pisano Chien-Lun Lan Hyun Cho Scott Fritz Jean Paul Talledo Vilela Mike MollenhauerEight-hundred fifty-seven fatalities occurred in work zones in the United States in 2020. One work zone fatality occurs for every 4 billion vehicle miles of travel and for every $112 million of roadway construction expenditures. NCHRP Web-Only Document 418: Modern Solutions to Safe and Efficient Work Zone Travel, from TRB’s National Cooperative Highway Research Program, is supplemental to NCHRP Research Report 1142: Innovative Approaches to Enhancing Safety and Efficiency in Work Zones: A Guide and seeks to identify best practices in leveraging technology to help the traveling public navigate roadway maintenance or construction work zones.
On-Bridge Stormwater Treatment Practices: A Guide
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Michael Barrett National Cooperative Highway Research Program James Lenhart Lynn Katz Maral Razmand Jack Lisin Ariel Mosbrucker Aaron PoreskyStormwater treatment of bridge deck runoff continues to be a design challenge. There is a growing need to develop more options for on-bridge treatment of stormwater that will address challenges, including, but not limited to, level of service, structural integrity, hydraulic function, litter and sediment loads, freeze-thaw cycles, maintenance operations, and work zone safety. NCHRP Research Report 1117: On-Bridge Stormwater Treatment Practices: A Guide, from TRB’s National Cooperative Highway Research Program, presents a guide for determining the feasibility of on-bridge stormwater treatments for bridges and what design, construction, and operation and maintenance approaches are necessary to mitigate risks and balance costs with environmental protection. Supplemental to the report is NCHRP Web-Only Document 401: Developing a Guide for On-Bridge Stormwater Treatment Practices, a conduct of research report summarizing the work that went into the development of the guide.
Open-Book Pricing Practices for Construction Manager/General Contractor and Progressive Design-Build Projects
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Douglas D. Gransberg National Cooperative Highway Research Program Marko PalaOpen-book negotiations for determining construction pricing for transportation agencies can enhance cost certainty, optimize risk allocation, and ultimately lead to more efficient project delivery. In a survey of 42 state departments of transportation (DOTs), key insights arise in how agencies negotiate construction costs post-award, collaborate with independent cost estimators, and manage project contingencies. Additionally, case examples reveal the critical role of trust and transparency in ensuring fair and reasonable guaranteed maximum prices. NCHRP Synthesis 653: Open-Book Pricing Practices for Construction Manager/General Contractor and Progressive Design-Build Projects, from TRB’s National Cooperative Highway Research Program, explores the complexities of alternative project delivery methods for state DOTs, with a focus on transparency, risk management, and cost negotiation.
Outcomes of Variability in Teen Driving Experience and Exposure: Evidence from Naturalistic Driving Studies
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Behavioral Traffic Safety Cooperative Research Program Tia Mastromatto Loren Staplin Michelle Duren Johnathon Ehsani Feng Guo Shu Han Lesheng Hua Sheila KlauerMotor vehicle crash rates for teen drivers during the learner’s permit phase are relatively low and comparable to those of adult drivers. However, once teenagers begin driving independently, the crash risk increases significantly at licensure and remains high during the first few months of solo driving. BTSCRP Research Report 13: Outcomes of Variability in Teen Driving Experience and Exposure: Evidence from Naturalistic Driving Studies, from TRB’s Behavioral Traffic Safety Cooperative Research Program, provides insights on how exposure to driving during the learner’s permit period and the first months of driving independently, including driving in diverse environments, impacts safety outcomes in later driving.
Parks and Other Recreational Uses on Airport Property
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Airport Cooperative Research Program C. Daniel PratherAirports that have publicly accessible parks or other recreational use spaces on airport property have reported strengthening community relationships. ACRP Synthesis 137: Parks and Other Recreational Uses on Airport Property, from TRB's Airport Cooperative Research Program, describes the experiences of airports that provide airport property for publicly accessible parks and other recreational uses. This effort includes documenting the development, management, and operation of existing airport programs; the perceived benefits and risks of utilizing airport property for parks and recreational uses; and how these uses can support community goals.
Pathways to an Equitable and Just Energy Transition: Principles, Best Practices, and Inclusive Stakeholder Engagement: Proceedings of a Workshop
by Division on Engineering and Physical Sciences Division of Behavioral and Social Sciences and Education Board on Environmental Change and Society Division on Earth and Life Studies Board on Atmospheric Sciences and Climate Board on Energy and Environmental Systems Transportation Research Board National Academies of Sciences, Engineering, and Medicine Committee on Accelerating Decarbonization in the United States: Technology, Policy, and Societal DimensionsWhile technologies are clearly instrumental in transitioning away from fossil fuel-based energy and toward a decarbonized economy, decisions about which technologies are prioritized, how they are implemented, and the policies that drive these changes will have profound effects on people and communities, with important implications for equity, jobs, environmental and energy justice, health, and more. The National Academies of Sciences, Engineering, and Medicine Committee on Accelerating Decarbonization in the United States: Technology, Policy, and Societal Dimensions was tasked with assessing the broad range of technological, policy, and societal dimensions of decarbonizing the U.S. economy. The committee produced a 2021 report that provides the U.S. government with a roadmap of equitable and robust decarbonization policies. The next report of the committee will address the broader range of policy actors who play a role in equitable energy transition. To inform its deliberations, the committee hosted a 1-day workshop on July 26, 2022 to discuss critical issues of equity and justice during the energy transition. The goal of the workshop, titled Pathways to an Equitable and Just Transition: Principles, Best Practices, and Inclusive Stakeholder Engagement, was to move beyond energy technologies and elicit ideas and insights to inform the development of principles, best practices, and actionable recommendations for a broad range of policy actors and stakeholders in order to fully operationalize equity, justice, and inclusion. This publication summarizes the presentations and discussion of the workshop.
Pay and Working Conditions in the Long-Distance Truck and Bus Industries: Assessing for Effects on Driver Safety and Retention
by Committee on National Statistics Division of Behavioral and Social Sciences and Education Transportation Research Board National Academies of Sciences, Engineering, and Medicine Consensus and Advisory Studies Committee for a Study of the Impacts of Alternative Compensation Methods on Truck Driver Retention and Safety PerformanceFor-hire trucking—as opposed to in-house private carriers that transport the goods of their parent company—is a large and heterogeneous industry with considerable variability in carrier sizes, operational structures, and freight markets served. For this sector, the Federal Motor Carrier Safety Administration should explore opportunities for leveraging research and data collection that may be planned and programmed for other purposes to help regulators, researchers, and industry examine the potential effects of driver compensation and work conditions on the safe driving behavior and performance of long-distance for-hire truck drivers. This is among the recommendations in TRB Special Report 355: Pay and Work Conditions in the Long-Distance Truck and Bus Industries: Assessing for Effects on Driver Safety and Retention, from the Transportation Research Board of the National Academies of Sciences, Engineering, and Medicine. The report examines—in response to a request from the U.S. Congress—the impacts of various methods of driver compensation on safety and driver retention, including hourly pay, payment for detention time, and other payment methods used in the industry.
Pile Design for Downdrag: Examples and Supporting Materials
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine National Cooperative Highway Research Program Amalesh Jana Armin W. Stuedlein Johnathan D. Blanchard Richard A. Coffman Aaron S. BudgeNCHRP Web-Only Document 398: Pile Design for Downdrag: Examples and Supporting Materials from TRB's National Cooperative Highway Research Program, provides appendices to NCHRP Research Report 1112: Design of Piles for Downdrag.
Planning for Future Electric Vehicle Growth at Airports
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Airport Cooperative Research Program Mia Stephens Sara Kaplan Angela Archibeque Krista Robertson Maranda Thompson Kate Andrus Grant Bennett Rex HazeltonBecause of the diversity of charging needs at airports and the varied policy environments in which airports operate, no single roadmap describes how to best install electric vehicle charging. Furthermore, an airport may use multiple approaches to owning and operating charging infrastructure. To help simplify this complex space, this planning guide categorizes charging into eight use cases. ACRP Web-Only Document 61: Planning for Future Electric Vehicle Growth at Airports, from TRB’s Airport Cooperative Research Program, is designed as a primer to help educate airport staff and practitioners on the technologies and processes associated with charging infrastructure. The guide was developed in Phase I of a project that will include additional products in Phase II.
Practices for Controlling Tunnel Leaks
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine National Cooperative Highway Research Program Katie Clever Thomas R. Leckrone Martha AversoWater infiltration is a common problem in tunnels. Such infiltration accelerates the deterioration of the structure and elements within and creates hazards in the form of icicles and slippery roadways. The severity of water infiltration often reflects various factors, so determining the appropriate remedy is challenging and frequently requires an extensive investigation to understand the source and location of the leak, the structural details of the tunnel, and the geology of the surrounding substrate. NCHRP Synthesis 627: Practices for Controlling Tunnel Leaks, from TRB’s National Cooperative Highway Research Program, documents the methods and practices used by state department of transportation tunnel owners to control tunnel leaks.
Practices for Operational Traffic Simulation Models
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Henry Brown National Cooperative Highway Research Program Praveen Edara Ahmad Abdallah Britton Johnson Dae Yeol ChangTransportation modeling applications can be divided into two categories: travel demand forecasting and operational modeling. Demand forecasting predicts future traffic volumes for long-term infrastructure investments; operational modeling focuses on specific problems at a near-term or finer level of detail (such as for improving the traffic signal timing along a corridor, identifying the causes of an existing bottleneck, assessing the mobility impacts of a planned construction project, or decision-making on alternative selection). NCHRP Synthesis 650: Practices for Operational Traffic Simulation Models, from TRB’s National Cooperative Highway Research Program, documents state department of transportation processes and procedures for the use of operational traffic simulation models.
Practices for Transportation Agency Procurement and Management of Advanced Technologies
by Kenneth Sullivan Transportation Research Board National Academies of Sciences, Engineering, and Medicine National Cooperative Highway Research Program Ken Baxter Kimberly Ann Gayle Turner Jeff Sawyer John Savicky Kristen Hurtado Jake Smithwick Brian LinesState departments of transportation (DOTs) have effective procurement processes for highway construction but lag in acquiring new business technologies. As they invest in advanced solutions for communications, asset management, and human resources, they aim to leverage artificial intelligence and cloud-based big data tools. However, traditional procurement methods typically relied on by state DOTs focus on individual purchases rather than long-term goals and often fall short in addressing the growing complexity of these systems and evolving customer needs. This can create challenges in acquiring technological products and services. NCHRP Research Report 1145: Practices for Transportation Agency Procurement and Management of Advanced Technologies, from TRB’s National Cooperative Highway Research Program, presents a guide that includes successful strategies and practices for procuring new and innovative transportation system technologies.
Practices to Identify and Mitigate PFAS Impacts on Highway Construction Projects and Maintenance Operations
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine National Cooperative Highway Research Program Roy E. Sturgill Jr. Joseph A. CharbonnetPer- and polyfluoroalkyl substances (PFAS) are a class of more than 6,000 contaminants of emerging concern that can harm both ecosystems and human health. These anthropogenic compounds contain carbon fluorine bonds that make them stable and persistent in the environment, earning them the nickname “forever chemicals.” NCHRP Synthesis 630: Practices to Identify and Mitigate PFAS Impacts on Highway Construction Projects and Maintenance Operations, from TRB’s National Cooperative Highway Research Program, documents current state departments of transportation practices for identifying locations of potential PFAS contamination and mitigating the impacts of PFAS related to highway construction and maintenance operations. This study considers PFAS impact and mitigation efforts in all phases of highway project development (planning, design, right-of-way acquisition), construction, and maintenance.
Preparing Successful No-Effect and No-Adverse-Effect Section 106 Determinations: A Handbook for Transportation Cultural Resource Practitioners
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine National Cooperative Highway Research Program Terry Klein Kate Umlauf Camilla McDonaldSection 106 of the National Historic Preservation Act requires federal agencies, including the U.S. Federal Highway Administration, to take into account the effects of their programs and projects listed in or eligible for listing in the National Register of Historic Places. NCHRP Research Report 1133: Preparing Successful No-Effect and No-Adverse-Effect Section 106 Determinations: A Handbook for Transportation Cultural Resource Practitioners, from TRB’s National Cooperative Highway Research Program, is designed to aid in the navigation of both the Section 106 and project development processes and address other various practitioner challenges. Supplemental to the report are NCHRP Web-Only Document 412: Creating a Handbook for Successful No-Effect and No-Adverse-Effect Section 106 Determinations, a technical memorandum on implementation of the research findings and products, and a PowerPoint presentation on the study.
Programs to Expand the Skilled, Technical Transportation Workforce: Proceedings of a Workshop
by Policy and Global Affairs Division of Behavioral and Social Sciences and Education Committee on Women in Science, Engineering, and Medicine Board on Human-Systems Integration Transportation Research Board National Academies of Sciences, Engineering, and Medicine Consensus and Advisory Studies DivisionPrograms to Expand the Skilled, Technical Transportation Workforce: Proceedings of a Workshop summarizes the Workshop to Broaden the Diversity of the Skilled, Technical Transportation Workforce held in September 2024 at the National Academies of Sciences Building in Washington, DC. The workshop was sponsored by the Federal Transit Administration and the National Science Foundation and brought together experts and educators across academia, government, and industry.
Protecting Transportation Employees and the Traveling Public from Airborne Diseases
by Transportation Research Board National Academies of Sciences, Engineering, and Medicine Kevin Dover National Cooperative Highway Research Program Transit Cooperative Research Program Anne Kerber Jacob Swanson Brenda Lopez Heejung JungTCRP Web-Only Document 78/NCHRP Web-Only Document 410: Protecting Transportation Employees and the Traveling Public from Airborne Diseases, a joint publication from TRB’s Transit Cooperative Research Program and National Cooperative Highway Research Program, provides information regarding strategies that reduce exposure to airborne contagions by transportation employees and passengers on various modes, especially in buses. It is supplemental to Mitigating Exposure to Airborne Diseases for Public Transportation Passengers and Employees: Executive Summary.
Quantitative Safety Analyses for Highway Applications
by John Campbell Transportation Research Board National Academies of Sciences, Engineering, and Medicine Daniel Cook National Cooperative Highway Research Program Jennifer Ogle Brelend Gowan Douglas W. Harwood Elizabeth Wemple Ingrid Potts Karen Dixon Darren TorbicDevelopment of the AASHTO Highway Safety Manual began from a TRB conference session and a workshop, both held in 1999, that identified the need for a traffic safety document analogous to the role of the Highway Capacity Manual for traffic operations. NCHRP Research Report 1140: Quantitative Safety Analyses for Highway Applications, from TRB’s National Cooperative Highway Research Program, describes a multiyear research process undertaken to improve the state of the practice for quantitative safety analyses for highway applications.
Reducing Conflicts Between Turning Motor Vehicles and Bicycles: Decision Tool and Design Guidelines
by David Hurwitz Transportation Research Board National Academies of Sciences, Engineering, and Medicine Jason Anderson Christina Fink Rebecca Sanders National Cooperative Highway Research Program Helena Breuer Hisham Jashami Jessica Schoner Sirisha Kothuri Nathan McNeil Chris Monsere Bill Schultheiss Jeremy ChrzanOne of the most common locations for fatal motor vehicle–bicyclist crashes is at intersections, which inherently have many conflicts related to turning. Reducing these conflicts is a key objective in improving intersection safety across all modes. Of particular concern for bicyclists’ safety at intersections are the conflicts between bicyclists travelling straight through the intersection and motor vehicle drivers making right turns and opposing left turns. NCHRP Research Report 1125: Reducing Conflicts Between Turning Motor Vehicles and Bicycles: Decision Tool and Design Guidelines, from TRB’s National Cooperative Highway Research Program, presents a decision tool and design guidelines to help highway safety practitioners reduce turning motor vehicle–bicycle conflicts at intersections. Supplemental to the report are NCHRP WOD 408: Design Options to Reduce Conflicts Between Turning Motor Vehicles and Bicycles: Conduct of Research Report and an implementation memo.