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 rollover crash of a 2019 Subaru Outback Limited in North Carolina in November 2022 driven by a belted 34-year-old female with a belted 70-year-old female front passenger. The Subaru crossed into the oncoming lane, traveling more than half a mile before veering off t
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This Special Crash Investigations report documents the fatal rollover crash of a 2019 Chevrolet Equinox that moved into the lane of a 2016 Honda CR-V. The Chevrolet went out of control, rolled down a dirt embankment and rolled over. The Chevrolet driver was pronounced deceased on-scene, and the belted 52-year-old front passenger was hospitalized fo
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Although visual inspections remain the primary method for bridge deck evaluation, they fail to detect hidden deterioration. Rapid-scanning nondestructive evaluation (NDE) techniques are gaining popularity, but their reliability compared with traditional methods is unclear. This study aimed to determine the reliability of multiple NDE methods for de
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Full depth reclamation (FDR) using emulsified asphalt or foamed asphalt continues to grow in usage throughout Texas. These mixtures typically use a cement additive in the mix design. The cement additive reportedly contributes to early strength gain, which can be particularly important for projects that require daily opening to heavy traffic. Howeve
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This project spanning the year 2025 set up 17 additional City intersections, raising the total locations reporting data to 19. Note that similar to the NDDOT sponsored pilot project, this phase of traffic data collection and reporting used existing infrastructure without the need to purchase or maintain any additional traffic data collection device
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This report covers analyses of Caltrans’ near-fault adjustment factors as recommended in the Caltrans Seismic Design Criteria. The report has two large chapters. Chapter 1 builds on prior the University of California Los Angeles studies that performed probabilistic seismic hazard analyses at numerous California sites across a range of return period
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Urban areas experience elevated pavement temperatures due to the urban heat island (UHI) effect, which increases cooling energy demand and associated carbon emissions. In this project, the work focused on three main components: (1) a comprehensive mechanical study of precast concrete mixes containing microencapsulated organic phase change material
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Elevated concentrations of air pollutants can have serious impacts on human health, the environment, and Colorado’s ecosystems. The Colorado Department of Transportation (CDOT) has prioritized protecting air quality in accordance with the Colorado Air Pollution Prevention and Control Act (Section 25-7-101 et seq., C.R.S., 2017). This research quant
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Effective drainage is critical for preserving pavement integrity and extending service life, yet network-level methods for evaluating pavement drainage conditions remain limited. This study presents a practical methodology for assessing pavement drainage conditions using data from the Louisiana Department of Transportation and Development’s (DOTD)
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Nighttime work zones pose increased risks for both drivers and workers due to the challenge of ensuring adequate visibility while minimizing glare. Current lighting practices vary widely across public agencies, often resulting in excessive illumination and poor glare control. This study evaluated the performance of nighttime lighting systems throug
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This objectives of this project were as follows: •Investigate how the characteristics of lighting—specifically glare, luminance, and visibility—affect the visual performance of construction workers. •Examine the influence of lighting arrangements (i.e., the orientation and positioning of light towers) on the perceptions of both construction workers
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United States. Department of Transportation. National Highway Traffic Safety Administration. National Center for Statistics and Analysis
2025-12-01
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Traffic Safety Facts
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PDF
In 2024 NHTSA began upgrading the Crash Investigation Sampling System (CISS) with provisions in the Infrastructure Investment and Jobs Act (IIJA), which said “to enhance the collection of crash data by upgrading the [CISS] to include – 1) additional data collection sites; 2) an expanded scope that includes all crash types; and 3) on-scene investiga
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Utility relocation at the Iowa Department of Transportation (Iowa DOT) is frequently cited as a cause of construction delays and increased highway project costs. This research aimed to enhance alignment between the utility coordination and project development processes by providing recommendations for integrating utility stakeholder partnerships ea
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Since 2009, the Idaho Transportation Department (ITD) has implemented the Alive at 25 national program in Idaho. Each year, thousands of young Idaho drivers participate in the program to learn how to be better and safer on the road. To date, the impact of this program on driver behaviors and attitudes is unknown. ITD contracted Boise State Universi
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This report presents a new framework for applying fines content corrections in soil liquefaction evaluations. Fines content affects both penetration resistance and cyclic resistance, but current methods use a single correction to represent both effects. This study separates these influences by using variable-rate CPT data to assess the effect of fi
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The primary purpose of this research was to develop and propose procedures for incorporating partnerships with utility stakeholders into the early stages of the project development process at the Iowa Department of Transportation (Iowa DOT), with the broader goal of streamlining workflows to reduce utility-related delays and cost overruns.
The impact of dedicated right-turn lanes at signalized intersections on pedestrian safety has been relatively understudied, particularly for urban areas. The authors reviewed the research literature and pedestrian crash data analysis on right-turning vehicles, performed a field study with both in-person observation and video recordings of sites wit
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This initiative constructed and studied a rapid strength gaining concrete mixture placed in MnROAD Test Cell 2437. The innovative concrete made from a belitic calcium sulfoaluminate (BCSA) cement was placed in a 36 ft by 12 ft test section on November 22, 2024, when the ambient temperature was approximately 35°F. The test cell was instrumented with
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Chloride-based brine deicers are widely used to maintain winter roadway safety, but their performance drops in extreme cold as meltwater dilutes the brine, and their runoff accelerates concrete deterioration, rebar corrosion, and ecological harm. This report investigates sustainable, high-performance deicing formulations that enhance low-temperatur
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A finite element analysis application was developed to determine the live load distribution widths/factors for standard and non standard axle configurations. This application will provide refined analysis to bridge rating engineers involved with load rating for inventory, operating, permits, and posting.
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