The US Transportation Collection consists of documents from across all transportation modes with specific focus on research reports from US DOT, state DOTs, and other transportation organizations.
Bookmark this collection: https://rosap.ntl.bts.gov/collection_ust or https://doi.org/10.21949/1530857.
This Special Crash Investigations report documents the on-site investigation of the fatal crash of a 2011 Chevrolet Silverado 3500 Type III ambulance, a 2017 Toyota RAV4, and a 2009 Infiniti G37X in Pennsylvania in 2022. The ambulance entered a four-way intersection and struck the Toyota, a traffic-control pole, and a tree. After the impact with th
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This Special Crash Investigations report documents the fatal rollover crash of a 2019 Ford E-350 Type III ambulance in North Carolina in 2022. The ambulance was transporting a patient with a heart condition without lights or sirens when it hit a patch of ice, skidded off the road and went down an embankment, and rollover. When the 84-year-old patie
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The Virginia Department of Transportation (VDOT) has successfully used in-place recycling strategies on approximately 40 pavement rehabilitation projects in the state during the past decade. One such technique, full-depth reclamation (FDR), is usually selected as an alternative to conventional reconstruction to rehabilitate failing pavements where
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The Virginia Department of Transportation utilizes the indirect tensile cracking test (IDT-CT) and the indirect tensile at high temperature (IDT-HT) test as part of its balanced mix design framework to evaluate asphalt mixture performance and support performance-based acceptance decisions. Although these tests are critical tools for assessing perfo
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This report benchmarks Design-Build (DB) and Progressive Design-Build (PDB) practices across 17 U.S. transportation agencies to inform Arizona DOT’s alternative-delivery program. It analyzes statutory provisions, DB manuals, and interviews with project stakeholders to document notable practices in cost control, risk allocation, training, DBE inclus
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The Virginia Department of Transportation (VDOT) initiated efforts to implement balanced mix design (BMD) in 2017, using 11 mixtures from a well-documented previous study in a benchmarking effort to select performance-related tests to use within the BMD framework and develop criteria for those tests. When these mixtures were produced and paved in 2
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Under the Moving Ahead for Progress in the 21st Century Act, state departments of transportation are required to report travel time reliability and set performance targets for interstate and non-interstate National Highway System facilities. Although several Virginia Transportation Research Council studies have analyzed and predicted travel time re
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The Arizona Department of Transportation (ADOT) is evaluating the feasibility of establishing a data management office (DMO) to enhance the accessibility, quality, and coordination of its data assets. As data grows in volume and strategic importance, transportation agencies nationwide have adopted formal structures to improve data governance. This
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The federally endangered rusty patched bumblebee (Bombus affinis) provides a difficult set of challenges for management and conservation. Bumblebee species have complex life histories, interacting with different obligatory habitat requirements across the ontogeny of the colony. Transportation corridors present unique opportunities for interventions
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The goal of the project summarized in this report was to research and develop criteria for updating and improving the ADOT Bridge Design Guidelines with respect to the strut-and-tie methodology defined in the AASHTO LRFD Bridge Design Specifications. To accomplish this goal, the existing literature was reviewed and bridge engineers in Arizona and a
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A critical durability factor for steel bridges is the long-term fatigue performance, which depends on the structure’s fatigue details, stress range, and cycle counts. Modern bridges account for these factors and have an infinite service life; however, bridges designed using previous fatigue provisions may experience cracking. Given the importance o
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This study presents the results and implementation strategies on the deployment of smart work zone equipment. A smart arrow board in combination with location beacons were tested towards understanding best practices, both informed by the test pilot and through a literature review, on the inclusion of such devices within work zones in Oregon. Furthe
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United States. Department of Transportation. National Highway Traffic Safety Administration
2025-11-01
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NHTSA recently issued a projection report of traffic fatalities and the fatality rate per 100 million vehicle miles traveled (VMT) for the first half of 2025 (Report No. DOT HS 813 756) that showed an estimated 17,140 people died in motor vehicle traffic crashes during the first half of 2025, a decrease of about 8.2 percent as compared to 18,680 fa
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United States. Department of Transportation. National Highway Traffic Safety Administration
2025-11-01
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PDF
This edition of Traffic Safety Facts Crash•Stats lists the most current data on the nationwide seat belt use rate in 2024 as calculated by probability-based observational surveys conducted by the 50 States, the District of Columbia, and U.S. Territories. In 2024 seat belt use in the United States ranged from 71.0 percent in the U.S. Virgin Islands
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An event data recorder records vehicle data just prior or during a crash (braking, air bag status and deployment, seat belt usage, etc., and then crash events), intended for retrieval after the crash to help crash reconstruction or vehicle safety research. NHTSA established CDR requirements in 49 C.F.R. § 563 in 2012. Since then, crash avoidance an
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Bridge scour is a leading cause of hydraulic-related bridge failures, yet current monitoring practices rely on periodic inspections that are insufficient during floods when scour activity accelerates. To address this gap, a low-cost (under $1,000 per unit) remote scour-monitoring system was developed and deployed on two scour critical bridges in Ge
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The leading cause of bridge failure globally is scour. Scour occurs when water flowing beneath a bridge excavates and carries away portions of the streambed. Traditional scour prediction methodologies were designed for course-grained or “cohesionless” materials. Different scour mechanisms exist for course-grained and fine-grained materials. This st
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The purpose of this study was to determine the immediate scour of un-weathered claystone bedrock in bridge configurations, i.e., around piers and/or constricted flow. This study evaluated the erodibility of un-weathered claystone found in the Colorado Front Range with the SRICOS-EFA (Scour Rate in Cohesive Soils – Erosion Function Apparatus) method
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In December 2022, the Virginia Transportation Research Council completed the technical assistance report, Potential for Electrification of the VDOT Vehicle Fleet, which investigated how electric trucks might integrate into the Virginia Department of Transportation’s (VDOT) fleet. That study was based on daily mileages of a sample of VDOT’s current
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This Excel Spreadsheet contains the Electric Vehicle Decision Support Tool: The life cycle cost analysis tool allows for a life cycle cost analysis comparison of multiple vehicles, including electric vehicles (EV), hybrid electric vehicles (HEV), and internal combustion engine vehicles (ICEV). The tool requires inputs about how the vehicle will be
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