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.
Longitudinal barriers (e.g., guardrails, median barriers, and bridge rails) are currently tested and evaluated at a design impact speed of 62 mph. Posted speed limits have increased in recent years. New or modified barrier designs may be needed to withstand high-speed impacts to maintain the desired level of safety for motorists traveling on high-s
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This report provides guidance for the establishment of native habitats in New England. It describes the seed mixes of native plants for various soil conditions, establishment of native habitats using various techniques, guidelines for conservation mowing and ecotypic seed production in the region.
This report explores the benefits of developing, using, and maintaining an inventory of traffic management system (TMS) assets and resources for State and local agencies. By documenting, inventorying, and configuring assets and resources, agencies can enhance the day-to-day management and operation of TMSs. Agencies may also benefit from incorporat
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United States. Department of Transportation. National Highway Traffic Safety Administration. National Center for Statistics and Analysis
2024-08-01
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In 2022 there were 13,524 fatalities in motor vehicle traffic crashes in which at least one driver was alcohol impaired. This represented 32 percent of all traffic fatalities in the United States for the year. Traffic fatalities in alcohol-impaired-driving crashes decreased by 0.7 percent (13,617 to 13,524 fatalities) from 2021 to 2022. One alcohol
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Privately owned and shared autonomous vehicles (AVs and SAVs) and automated trucks (ATrucks) are coming to the US and Texas. This project updated TxDOT’s Statewide Analysis Model (SAM) to integrate AVs, SAVs, and ATrucks as added transportation modes. For passenger trips over 50 miles (one way), the nested logit model was modified to include househ
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United States. Department of Transportation. National Highway Traffic Safety Administration. National Center for Statistics and Analysis
2024-08-01
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From 2013 to 2022 there were 976 fatal school-transportation-related traffic crashes, and 1,082 people of all ages were killed in those crashes—an average of 108 fatalities per year. A school-transportation-related motor vehicle traffic crash directly or indirectly involves a school transportation vehicle that is either a school bus body type or a
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Cold-recycling processes such as Cold in Place Recycling (CIR) and Cold-Central Plant Recycling (CCPR) offer opportunities for innovation through the use of recycling additives (RAs). The objective of this project was to evaluate the efficacy of rejuvenating asphalt emulsions in the CIR and/or CCPR process in terms of potential performance benefits
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This Phase II project aimed to accumulate more field test data to improve the standards for the implementation of the Zorn lightweight deflectometer (LWD) for the acceptance of unbound materials layers. Five more different soils, including New Florence CL (lean clay), Holts Summit GM (silty gravel), Sikeston SM (silty sand), Rolla CL (lean clay), a
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This Phase II project aimed to accumulate more field test data to improve the standards for the implementation of the Zorn lightweight deflectometer (LWD) for the acceptance of unbound materials layers. Five more different soils, including New Florence CL, Holts Summit GM, Sikeston SM, Rolla CL, and Rolla GM, were collected from different project s
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Field sands have been used in hot mix asphalt (HMA) pavements to improve workability since they are readily available and less expensive than crushed materials. However, due to their potential adverse effects on performance, field sands are typically limited to 10% of the aggregates. A key issue is the presence of harmful clay particles that can si
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Severe winter weather poses a significant threat to road users, primarily due to slippery road surfaces, which considerably increase the risk of crashes and injuries. Additionally, such conditions can disrupt traffic flow on highways, causing speed reductions, decreased highway capacity, or even complete traffic lockdowns. Most Departments of Trans
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This report thoroughly investigates and analyzes the diverse factors influencing incident occurrence in work zone environments, aiming to identify areas where proactive planning can enhance incident mitigation. Drawing from an extensive review of existing literature on work zone safety, 37 factors affecting both public and occupational safety were
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United States. Department of Transportation. National Highway Traffic Safety Administration. National Center for Statistics and Analysis
2024-08-01
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In 2022 there were 7,971 people 65 and older killed and an estimated 268,622 injured in motor vehicle traffic crashes. Older people made up 19 percent of all traffic fatalities and 11 percent of all people injured in 2022. Compared to 2021 there was a 6-percent increase in the number of traffic fatalities and a 1-percent increase in the estimated n
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United States. Department of Transportation. National Highway Traffic Safety Administration. National Center for Statistics and Analysis
2024-08-01
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In 2023 seat belt use in the United States ranged from 68.2 percent in the U.S. Virgin Islands to 98.4 percent in Hawaii. Twenty-seven States, the District of Columbia, Guam, Puerto Rico, and the Northern Mariana Islands achieved seat belt use rates of 90 percent or higher. These results are from probability-based observational surveys conducted by
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This study aimed to forecast the time to failure of aging, deteriorating clay embankments supporting transportation infrastructure. This study utilized the user-defined subroutines that were developed and implemented by Morsy et al. to allow transient calculations of coupled hydromechanical behavior.
This study examines rural transit needs for Jaunt. The objective is to quantify the need for transit services in each of Jaunt’s partner jurisdictions. Jaunt provides transit in the city of Charlottesville, Virginia, and the counties of Albemarle, Buckingham, Fluvanna, Greene, Louisa, and Nelson. Neighboring Goochland County is also included in the
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Since Fiscal Year 2017, the Texas Department of Transportation (TxDOT) has employed advanced automated and semi-automated techniques using 3D laser technology and high-resolution cameras to collect pavement condition data over 197,000 lane miles. Although this approach marks a significant technological advancement, concerns about the accuracy and p
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This project aims to redesign the existing ramp closure gate used by Louisiana DOTD. The research team will utilize FE computer simulations and laboratory crash testing to develop a modified design that both passes MASH test protocols consistently and meets the functional requirements.
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