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Employees of state departments of transportation (DOTs) face numerous and dynamic hazards while executing their job duties, including work near moving equipment, work near the traveling public, and work during and responding to natural hazard events. In response, DOTs deploy a wide variety of occupational safety training to provide their employees with the knowledge, skills, and abilities to execute their job duties safely. That wide variety includes various topics, various cycles for updating, various modes of delivery, and various metrics for deployment, among other related issues.

NCHRP Synthesis 665: Occupational Safety Training and Knowledge Sharing for State DOT Employees, produced by TRB’s National Cooperative Highway Research Program, examines how state departments of transportation develop, deliver, evaluate, and update occupational safety training programs. It documents agency practices related to training delivery methods, required training by job function and supervisory level, agencywide versus district-specific programs, and the use of safety data and performance metrics to guide training decisions. The synthesis also reviews approaches for onboarding new employees, measuring training effectiveness, gathering employee feedback, developing specialized training, and involving experienced staff in the creation of in-house training materials. In addition, it examines knowledge transfer planning and the extent to which safety training is provided by in-house staff, consultants, or third-party training providers.

Transportation infrastructure—including buried utilities, drainage systems, and culverts—is frequently subjected to significant external stresses arising from existing conditions and new construction, especially in urban environments where deformation and failures can lead to significant operational and safety consequences. Lightweight fills offer a viable strategy to mitigate these stresses by reducing imposed loads. This study investigates the use of lightweight fills, specifically Foamed Glass Aggregate (FGA), as a sustainable solution to support California Senate Bill 1 (SB1) efforts to repair and maintain culverts, as well as for new construction applications. A numerical investigation was conducted to evaluate the performance of culverts backfilled with FGA compared to conventional fills. Models were developed for reinforced concrete box culverts and corrugated steel pipe culverts, and parametric analyses were performed across a range of configurations. Results indicate that FGA significantly reduces soil stresses, structural demand, deformation, and settlement compared to conventional fills. This study also developed design and construction guidance and proposed updates to Caltrans manuals to facilitate implementation in practice. The findings demonstrate that FGA is an effective, sustainable alternative for improving culvert performance in California and beyond, helping agencies better address aging infrastructure and increasing construction demands.

Throughout their transit journey, travelers with full vision can easily use visual information in the form of digital content, maps, and signs to find their way. However, this information is often not usable by people who are blind or have low vision (B/LV) who may use public transit alone or in combination with other modes of transportation. Therefore, it is crucial for transit agency leaders and staff to thoughtfully design and provide accurate, timely, and usable information in ways that passengers with vision disabilities can use to successfully take transit trips. It is also critical for transit agencies to understand that information equivalency is not only a good practice; it is required by federal law.

TCRP Research Report 264: Providing Passenger Information to People Who Are Blind or Have Low Vision: A Guide, produced by TRB’s Transit Cooperative Research Program, provides transit agencies and their local partners with up-to-date guidance to help make passenger information accessible to people who are B/LV. The guide provides foundational information on B/LV, including the spectrum and prevalence of vision disabilities, beneficial tools and training, and the concept of the complete trip. It also addresses accessibility requirements and standards, as well as strategies for providing accessible passenger information through multiple channels, including digital resources and staff. Tools are provided to help transit agencies evaluate the accessibility of their current passenger information and identify opportunities for improvement. The guide and tools are not officially adopted standards and do not have the force of law or official policy. Throughout the report, B/LV refers to vision issues, up to and including full blindness, that make everyday activities difficult and cannot be corrected with glasses, contacts, medicine, surgery, or other standard treatments.

The U.S. Department of Transportation (DOT) seeks to eliminate roadway deaths and serious injuries (FHWA, 2025). Achieving this goal requires reducing vehicle crashes, particularly roadway departure crashes, which account for approximately 55% of all fatal crashes and 66% of fatal crashes on rural two-lane highways. Common countermeasures include centerline rumble strips (CLRS) and shoulder rumble strips (SRS), which help prevent lane and roadway departures and help reduce fatalities, injuries, and property damage. However, their use also raises concerns about the safety of other road users, including bicyclists.

NCHRP Research Report 1186: Impacts of Rumble Strips on Driver Behavior and Bicyclist Safety, produced by TRB’s National Cooperative Highway Research Program, provides guidance on the application of CLRS and SRS on high-speed, two-lane highways, with a focus on their effects on bicyclist safety. The report examines the safety impacts of CLRS and SRS on bicyclists traveling on rural high-speed, two-lane roadways and characterizes motorists’ behavior during interactions with bicyclists on roads where these treatments are present.

Highway infrastructure inspection helps ensure that construction meets plans, specifications, and material requirements while supporting the quality and longevity of transportation assets. Infrastructure owners are increasingly using emerging remote virtual inspection (RVI) technologies, including mobile devices, AI, machine learning, light detection and ranging, small uncrewed aerial systems, and remote imaging technologies such as augmented reality, virtual reality, and closed-circuit television. RVI technologies have numerous applications, including quantity estimation, verification and acceptance processes, payment scheduling, progress tracking, and the generation of as-built records to support future maintenance efforts. However, effective adoption requires thoughtful implementation and an understanding of each technology’s capabilities and limitations.

NCHRP Research Report 1172: Virtual Inspection Systems for Highway Construction Projects: A Guide, produced by TRB’s National Cooperative Highway Research Program, explores the fundamental principles, organizational strategies, governance mechanisms, readiness assessments, and practical examples for effectively integrating digital technologies and systems into RVIs. The guide is organized into four parts covering management guidance, technical reference, practical case studies, and key takeaways to support the understanding and implementation of RVI technologies.

Human trafficking affects hundreds of thousands of minors and adults in the United States through labor and sex trafficking. Organizations such as TAT, Polaris, the Department of Homeland Security Blue Campaign, and state transportation agencies have developed strategies to identify trafficking, assist victims, and reduce demand. Successful efforts often rely on strong partnerships and educating individuals to recognize and report signs of trafficking. Collaboration among agencies, organizations, businesses, and communities is essential to disrupt trafficking networks and ensure that victims are identified, protected, and connected with appropriate services.

NCHRP Research Report 1191: Countering Human Trafficking: A Toolkit for State DOTs, produced by TRB’s National Cooperative Highway Research Program, addresses the role of state departments of transportation in disrupting human trafficking. The toolkit has two primary components: leadership-focused tools and operational-focused tools. The leadership-focused tools are designed to assist administration officials and executives in making key decisions to initiate a program to disrupt human trafficking and include a quick guidance document, an executive primer, and a policy guide. The operational-focused tools are designed to help agencies develop and implement the actions they decide to pursue and include outreach materials and a training guide.

The movement of overweight or heavy vehicles with increased axle and tire loads can cause premature pavement damage and accelerate deterioration. For state transportation agencies to effectively manage their pavement systems and consider alternative rehabilitation or design strategies for heavy-load movements, the impacts of such vehicles and the associated pavement damage must be assessed. Assessing pavement impacts under heavy loads is resource-intensive and challenging, given the iterative nature of the design process. Despite their significance, low-volume roads (LVRs) typically receive less attention than their high-volume counterparts because of resource constraints. Therefore, it is important to understand how state departments of transportation (DOTs) assess the impacts of heavy loads on LVRs, particularly because the design of LVRs differs significantly from that of typical high-volume roads.

NCHRP Synthesis 666: Design and Evaluation of Pavements for Low-Volume Roads with Heavy Loads, produced by TRB’s National Cooperative Highway Research Program, examines LVRs exposed to heavy, overweight, or nonstandard traffic, which can increase the risk of rapid deterioration and premature failure. The report focuses specifically on LVRs managed by state DOTs; practices of local agencies, such as those of cities, counties, and townships, are not included. Topics covered include pavement design and modifications, permitting requirements, structural impacts and failures, performance monitoring and maintenance strategies, springtime load restrictions, and case examples of design approaches for LVRs subjected to heavy loads.

Time allowances and recovery margins in rail scheduling are incorporated into travel time estimation and minimum headways to prevent delays from affecting subsequent trains. These margins act as a buffer against service irregularities, such as variations in station dwell times and train performance, and they are a key factor in rail capacity calculations. Most contemporary tools used to analyze or construct timetables calculate running times specific to each train. However, the factors influencing running times are inherently uncertain, including human behavior, weather conditions, train composition, ongoing infrastructure projects, rolling stock, and route conditions. To accommodate these uncertainties, transit planners and agencies incorporate time allowances into running time estimation, while applying operating or recovery margins to minimum headways to limit delay propagation.

TCRP Research Results Digest 122: Operating Margin and Recovery Factor Practices for Travel Time Estimation and Rail Scheduling, produced by TRB’s Transit Cooperative Research Program, explores the methodologies used by transit agencies to estimate more robust runtimes. These methodologies, among other elements, help establish operating margins and recovery factors in rail scheduling. This research informed updates to Chapter 8 of the TCQSM 4th edition. The digest describes one of 12 small research tasks conducted to support the development of new content for the 4th edition.

The article describes the Washington State Department of Transportation’s (WSDOT) efforts to implement wildlife crossing structures, which aim to improve habitat connectivity and reduce wildlife-vehicle collisions. It highlights the state’s data-driven prioritization framework, established under the Washington Habitat Connectivity Action Plan, to identify and target high-risk highway segments. Additionally, the text underscores the importance of long-term monitoring, often done in partnership with universities, to document the ecological and safety successes of these structures.

Adverse weather conditions such as rain, snow, fog, and high winds pose significant challenges to roadway safety and mobility. These conditions not only increase the risk of crashes but also contribute to travel delays, congestion, and unpredictable driving behavior. To mitigate these risks, transportation agencies are increasingly deploying variable speed limit (VSL) and real-time warning (RTW) systems, which use real-time data to dynamically adjust speed limits and provide timely hazard alerts.

NCHRP Research Report 1176: Real-Time Warnings and Variable Speed Limits— Safety and Travel Reliability During Weather Events, produced by TRB’s National Cooperative Highway Research Program, is a guide designed to support transportation professionals in understanding, evaluating, and implementing these systems in response to adverse weather conditions. The strategies and case studies included in this guide are intended to help transportation agencies enhance roadway safety, improve traffic flow, and ensure drivers receive accurate, timely information to navigate hazardous conditions effectively.

The same project that produced NCHRP Research Report 1176 also documented its methodology and findings in NCHRP Web-Only Document 447: Evaluating the Impacts of Real-Time Warnings and Variable Speed Limits on Safety and Travel Reliability During Weather Events.

This publication is an official Crash-Stats Brief Statistical Summary issued in July 2026 by the National Highway Traffic Safety Administration's (NHTSA) National Center for Statistics and Analysis. The report's primary purpose is to provide early, near-real-time statistical projections of national, regional, and state-level motor vehicle traffic fatalities and fatality rates per 100 million vehicle miles traveled (VMT) for the first quarter of the year. To generate these early projections before final census data is completed, NHTSA employs a time series cross-section regression methodology that models the relationship between monthly data from the Fatality Analysis Reporting System (FARS), NHTSA’s non-public Early Notification (EN) program, and Monthly Fatality Counts (MFC). These traffic safety estimates are further calculated using VMT projections provided by the Federal Highway Administration (FHWA). Overall, this document serves as a preliminary forecasting instrument designed to rapidly catalog and share safety trends with the broader highway safety community, with the understanding that these early estimates will undergo minor statistical revisions over the next two years as final FARS files are processed.

The Montana Department of Transportation installed nearly 600 miles of sinusoidal centerline rumble strips (SCLRS) in 2021. These were mostly installed on high-speed, two-lane rural highways, in the Kalispell Division and Missoula area. The sinusoidal pattern produces lower exterior noise levels than conventional centerline rumble strips, but the safety effects of the pattern have not been quantified. This study performed an observational before-after analysis of the SCLRS installation on two-lane rural highways using the Empirical Bayes (EB) methodology. Crash modification factors (CMFs) for a variety of crash types were less than 1.0, indicating that SCLRS were associated with a reduction in crash frequency. The CMF associated with total target crashes—defined as opposite direction collisions—was 0.711 while the CMF associated with fatal plus injury target crashes was 0.624. The only CMF that exceeded 1.0 was for the single-vehicle run-off-the-road crash type; however, this result was not statistically significant. This study also compared the safety performance of the SCLRS to that of conventional centerline rumble strips in Montana. Because the installation dates of the conventional pattern were unknown, a causal inference framework was used for evaluation. The results indicate that the CMFs for the conventional and sinusoidal patterns have confidence intervals that overlap, suggesting similar safety performance associated with the two patterns. An economic evaluation found that both centerline rumble strips patterns have a benefit-cost ratio exceeding 1.0.