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.
Reinforced soil slopes (RSSs) can be a feasible solution for embankments where there exist right of way restrictions, environmental issues, rolling or mountainous topography, unfavorable geology, and other limiting fac-tors. They can be an alternative to retaining walls or importing select fills to construct steeper, stable embankment slopes where
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This research examines the value of financing infrastructure improvements through bonding versus a program of pay-go improvements. Postponed construction becomes more costly in nominal terms because inflation raises the cost of construction over a longer period before construction begins. However, postponements can also create a variety of other si
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The Highway Division of the Iowa Department of Transportation (Iowa DOT) engages in research and development for two reasons: first, to find workable solutions to the many problems that require more than ordinary, routine investigation; and second, to identify and implement improved engineering and management practices. Detailed information on each
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The objective of this project was to create a book that encompasses the Iowa Highway Research Board’s (IHRB’s) history and funded projects from 2000 to 2024.
The Alabama Department of Transportation (ALDOT) is currently using the Alabama Design and Analysis of Pavement Thickness (ADAPT) software for their structural pavement design process, which is based on the 1993 American Association of State Highway and Transportation Officials (AASHTO) Pavement Design Guide. In 2008, the American Association of St
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This report examines some of the economic and real estate impacts of Connecticut’s CTfastrak and Hartford Line transit systems through a multi-phase, data-driven study. Findings reveal evidence that proximity to transit stations is associated with increased property values, higher property tax revenues, reduced residential and commercial vacancies,
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Research was undertaken to determine the effectiveness of various speed warning technologies across a variety of critical speed-change contexts in order to provide guidance to support future installation and operation of such treatments in Michigan. The speed warning technologies evaluated in this research included dynamic speed feedback signs (DSF
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Departments of Transportation need measurement tools to (1) assess and track over time populations and geographies where mobility investments are needed, (2) assess what is driving the mobility needs of different populations and geographies so as to identify possible interventions, and (3) evaluate the impact of department investments on mobility.
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Roadside vegetation composition assessment is essential to maintain ecological stability, control invasive species, and to ensure the adoption of environmental regulations around construction zones. Traditional monitoring methods involving visual inspections are time-consuming, labor-intensive, and not scalable. Remote sensing offers a valuable alt
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This project investigated the use of evolving machine vision technologies to improve asset management procedures. Machine vision is technology that enables machines to “see” and interpret images, similar to how humans see and understand the world. It includes capturing an image, analyzing the image, and then completing and action or decision based
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Temporary bridges are systems designed for an expected service life of 5 years. In 2011, the California Department of Transportation issued a memo to designers advocating the use of design spectra corresponding to a return period of 100 years for temporary bridges. However, broad consensus on the most appropriate hazard level and design approach is
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MaineDOT has a family of transit plans that have been developed over the past five years through collaborative efforts with partners and stakeholders. These plans share similar themes, guidance, and recommendations and tie into the Department’s Long-Range Transportation Plan, which was completed in 2023. This report complements those plans, reviewi
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This study developed a data-driven geospatial tool to optimize emergency response strategies for vehicle crashes in Kansas. The tool analyzed more than a decade of crash data from the Kansas Department of Transportation (KDOT) and the Fatality Analysis Reporting System (FARS) to provide insight into T1 (crash to emergency medical services [EMS] not
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This study developed a data-driven geospatial tool to optimize emergency response strategies for vehicle crashes in Kansas. The tool analyzed more than a decade of crash data from the Kansas Department of Transportation (KDOT) and the Fatality Analysis Reporting System (FARS) to provide insight into T1 (crash to emergency medical services [EMS] not
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Open-graded friction course (OGFC) is a thin asphalt mixture surface layer. It is gap-graded with a high percentage of coarse aggregates that are nearly uniform in size, resulting in a high percentage of interconnected air voids and asphalt binder, which provides improved skid resistance, visibility, and decreased pavement-tire noise. However, cons
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Open-graded friction course (OGFC) is a thin asphalt mixture surface layer. It is gap-graded with a high percentage of coarse aggregates that are nearly uniform in size, resulting in a high percentage of interconnected air voids and asphalt binder, which provides improved skid resistance, visibility, and decreased pavement-tire noise. However, cons
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The objective of this study was to develop and evaluate a new generation of open-graded friction courses (OGFC) that would provide superior durability performance while preserving the functional benefits of the mix. Additionally, a Finite Element (FE) model was developed and used to propose new air voids (AV) guidelines for OGFC applications in Lou
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This report presents the findings of a laboratory study conducted by the Sustainable Geotransportation/Geoenvironmental Infrastructure (SGI) Research Group at George Mason University. The research focused on investigating the ability of standard (S) and elasticized (E) expanded polystyrene (EPS) to provide elastic inclusion in integral abutments. E
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This report develops robust estimation models to address data challenges for identifying disadvantaged populations, defined by low-income, racial minority, and limited English proficiency (LEP) status, which aligns with the Virginia Department of Transportation’s (VDOT) SMART SCALE definition. The current reliance on American Community Survey data
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For the Virginia Department of Transportation (VDOT), substructure repairs are costly, and the durability is a concern. Current conventional concrete removal methods commonly use chipping hammers and shotcrete or self-consolidating concrete (SCC), plus discrete galvanic point (DGP) anodes, for such repairs. The types of concrete VDOT uses in these
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