Document Library

This study evaluated the effects of R1-6a pedestrian crossing signs, installed in various configurations, on driver yielding behavior at uncontrolled marked crosswalks across six Oregon locations. The research analyzed both staged and naturalistic crossings under different experimental conditions, including baseline, tubular markers, single and multiple R1-6a signs, and gateway installations. Video data were coded to assess crossing volumes and yielding rates for over 5,900 pedestrians. Baseline yielding was already high, averaging 85% nearside and 89% farside, but increased further with sign treatments. The gateway configuration achieved the highest yielding rates of 92% (nearside) and 97% (farside), while curb-top edge sign placement produced 87% nearside yielding and 99% farside yielding. These findings demonstrate that R1-6a signs, particularly in gateway configurations, enhance driver yielding even when baseline compliance is high, though variations across sites highlight the influence of differing roadway contexts and pedestrian environments.

This fact sheet, sponsored by Desjardins Insurance, examines the magnitude of and trends in collisions involving driver speed in motor vehicle fatalities in Canada from 2000 to 2023 using data from TIRF’s National Fatality Database (TIRF, 2026). Fatalities included in this analysis occurred on public roadways with persons dying within 30 days of the collision and at least one of the vehicles involved was a principal highway vehicle (i.e., automobile, van, truck, motorcycle, bus). Topics explored in this fact sheet include the role of driver speed in road deaths, characteristics of speeding drivers killed in collisions, and characteristics of speed-related collisions resulting in fatalities, including temporal factors, vehicle type, occupants and geographic location.

For more than a decade, the AAA Foundation for Traffic Safety (AAAFTS) has measured Americans’ traffic safety culture through its annual Traffic Safety Culture Index (TSCI) survey. The TSCI evaluates five key dimensions: how dangerous drivers perceive risky driving behaviors to be, how likely they believe they are to be apprehended for engaging in risky driving behaviors, how much social disapproval they associate with risky driving behaviors, how frequently they report engaging in risky driving behaviors themselves, and their support for safety laws related to risky driving behaviors. The 2025 TSCI builds upon this established framework by incorporating additional measures related to contextual and personal influences on driving behavior. First, this survey examines drivers’ perceptions of both safe and risky driving behaviors in their own neighborhoods. Such perceived neighborhood driving behaviors may shape individuals’ own driving behavioral choices, as prior research suggests that drivers tend to follow and imitate the behaviors of those around them (Mohammadi et al., 2021; Zhang et al., 2025). Second, the survey explores self-appraisals of behavior and abilities, which may be systematically biased by the “better-than-average effect,” a well-documented tendency for drivers to rate their own skills and behaviors more favorably than those of their peers (Horswill et al., 2004; Horswill et al., 2013). This bias is frequently associated with overconfidence and an increased likelihood of engaging in risky driving behaviors (Măirean & Havârneanu, 2018; Horrey et al., 2015). Third, this survey explores drivers’ social stress. Previous research has indicated that elevated social stress levels can contribute to increased distraction, aggression, and impairment behind the wheel (Suhr & Dula, 2017). These additional measures provide a more comprehensive picture of the factors influencing risky driving behaviors.

The tables in this document summarize the U.S. motorcycle population between 2002 (the earliest available year of data) and 2026, based on Institute analyses of data provided by S&P Global Mobility. Registration counts as of January 1 of each year were provided by year, state, and Vehicle Identification Number (VIN) pattern (first 10 digits). Software developed and maintained by the Highway Loss Data Institute (HLDI) was used to decode VIN patterns to determine make, series, and model year, and to append information maintained by HLDI on motorcycle type and antilock braking system (ABS) availability. Only on-road classes of motorcycles were included. Since the VIN information is constantly improving, counts in this paper may differ slightly from the previous versions.

Noise barriers along high-volume roads reduce traffic noise using either normal-weight materials, such as concrete or brick, or
lightweight materials, such as metal, composites, fiberglass, or acrylic. Although the Virginia Department of Transportation’s
(VDOT) current concrete noise barriers have proven durable, some lightweight metal noise barriers have failed prematurely
because of corrosion, prompting the need to better understand the field performance of lightweight alternatives. This project
aimed to improve the life-cycle management of VDOT’s noise barrier inventory through field evaluations of lightweight
barriers, development of an inspection and asset management framework, and unmanned aerial system (UAS) trial inspections

This guide is designed for State and local officials as well as non-government organizations and advocates who are interested in
partnering with Tribes in their area to improve traffic safety through occupant protection, specifically seat belt use. This guide was
made possible through a collaborative effort that included representatives from Indian Country across the United States, including
Tribes, nations, bands, villages, pueblos, rancherias, as well as State and Federal transportation safety officials and Tribal liaisons.
The guide
• outlines a framework based on asking questions and listening to build understanding and trust between Tribes and the State
and local officials with they will work with;
• provides an overview of sovereignty, Tribal land status, and Indigenous Knowledge and practices and their impact on laws,
enforcement, partnerships, and data; and
• offers suggestions for designing funding mechanisms to better respond to the needs of Tribes.
There are examples and case studies throughout the guide. It also includes an extensive resource section to broaden understanding
of the topics.

The Louisiana Department of Transportation and Development (DOTD) continues to improve its geotechnical data management policies and expand its use of digital data for geotechnical design. New advanced data-rich techniques and methodologies have been developed for geotechnical site characterization, including those recommended by the Advanced Geotechnical Methods in Exploration (A-GaME) program of the Federal Highway Administration (FHWA). Specifically, this research focused on the development and implementation of a web-based platform to efficiently visualize and interpret geotechnical data and help facilitate project delivery. The web-based platform can incorporate geotechnical data from DOTD’s OpenGround dataset, gINT files from consultants, and/or Data Interchange for Geotechnical and Geoenvironmental Specialists (DIGGS) data files for analysis based on the American Association of State Highway Transportation Officials (AASHTO) Section 10 and FHWA Geotechnical Engineering Circular No. 5 (GEC-5) updates.

Virginia and other states face growing shortages of traditional supplementary cementitious materials (SCMs) like fly ash, threatening concrete supply, cost, and VDOT infrastructure performance while hindering efforts to lower cement's global warming potential. To address these supply and sustainability challenges, this study evaluated limestone calcined clay cements (LC3 and LC2) as alternative SCMs, comparing their fresh, mechanical, durability, shrinkage, and environmental properties against VDOT standard Class F coal ash and slag cement.

National RTAP’s Mobility Management in Rural and Tribal Areas technical brief explains the guiding principles, partnership structures, and core competencies that support effective mobility management. It serves as both an educational resource and a practical reference for mobility managers, transit professionals, planners, and decision-makers seeking to design or strengthen coordinated transportation systems.

At seventy, the Interstate Highway System continues to provide significant safety and reliability
benefits, but is deteriorating, experiencing increased congestion as vehicle travel grows quickly, and is
aging rapidly yet there is no adequate plan for its long-term health. While it remains the workhorse of
American travel as the U.S. celebrates its 250th year, the Interstate Highway System is suffering from
severe wear and escalating congestion. To meet future demands, the system urgently requires
sweeping modernization, capacity expansion, and foundational reconstruction.

In 2019, the Transportation Research Board (TRB) provided Congress with a report that found
that the nation’s Interstates are heavily congested and aging, with large portions of the system in need
of major rebuilding and comprehensive upgrades. The report found that addressing the needs of the
Interstate Highway System will require more than a doubling of current investment to adequately
improve the system’s condition, reliability and safety, and that the restoration of the nation’s
Interstate Highway System should be based on a strong collaborative effort between federal leadership
and the states.

TRIP’s America’s Interstate Highway System at 70 report provides the latest information on the
Interstate System, including its benefit in saving lives, time and money, pavement conditions, bridge
conditions, travel trends, traffic congestion levels, truck use, and traffic safety. It reviews the findings
of the TRB Interstate report and concludes with recommended actions - based on the findings of the
TRB report - to ensure that the system can meet the nation’s transportation needs.

Factsheet presenting crash statistics from the Fatality Analysis Reporting System (FARS) and the Crash Report Sampling System (CRSS) focusing on children (persons aged 14 and under).

Precast/prestressed concrete girders with cast-in-place decks are commonly used for bridge construction throughout the United States. However, girder lifespans exceed the lifespans of concrete decks, resulting in the need for deck replacement. This study surveyed United States Department of Transportation (DOT) engineers to determine common deck removal practices. Survey results showed that, although most states have a need to replace bridge decks, few states have comprehensive plans for assessing the long-term effects of deck replacement on girder behavior. This study developed a Python model to estimate girder behavior over its lifespan that accounts for the effects of deck replacement, changes in loading conditions, changes in restraint conditions, and concrete deformations. Time-step analysis was used to calculate incremental changes in girder behavior throughout time, considering several lifespan stages delineated by changes in loading or boundary conditions. The B4 model (Wendner et al., 2013) was used to estimate the creep and shrinkage strain in the concrete. The model was validated against examples in the literature and applied to an example bridge to illustrate function. Modeling results suggest that deck replacement had minimal effect on long-term girder behavior for the bridge considered. A parametric study was also conducted to evaluate the influence of input parameter variations on long-term prestress loss, deflections, and stresses and strains for the example bridge. Parametric study results showed that girder behavior varies widely based on input parameters, suggesting that more research is needed to determine whether other bridge configurations would also be insensitive to deck replacement.