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.
Researchers evaluated the existing pavement conditions of the candidate section. A visual survey was conducted to identify existing distresses that are prevalent on the CPCD. An FWD testing was conducted to measure the structural capacity of the CPCD by obtaining slab deflections and calculating the load transfer efficiency (LTE). The CRCP overlay
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The project team compiled and reviewed existing road cross-section guidance (for urban, suburban, and rural environments), along with research findings, to identify content that would be appropriate for inclusion in Texas-based guidelines for cross-section optimization. A subsequent task focused on considering the data needs for assessing a propose
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Sediment control devices (SCDs) are used on construction sites to retain sediment and prevent stormwater from adversely affecting adjacent waterways. SCDs include silt fences, wattles, sediment logs and basins, filter dams, and inlet protection devices. These products are designed to be installed for specific applications (e.g., curb inlets, drop i
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Over 140 million tons of recycled concrete aggregate (RCA) are produced in the United States per year (ACPA, 2009), and this material has been used in a host of transportation infrastructure applications, including fills, embankments, bases, subbases, and concrete pavements. Currently, TxDOT limits the maximum amount of recycled crushed concrete fi
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Geogrids are used within the base or as a subgrade/base interface layer for enhancing the performance of flexible and rigid pavements. While there has been significant use, particularly in Texas, of geogrid-reinforced pavements, limited research has dealt with the methodologies of quantifying their influence on pavement performance. In the state of
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The research study included experimental testing and numerical modeling to obtain and develop much needed experimental data and analytical tools to study the performance of seamless systems, identify design issues, and propose design guidelines for the U.S. practice.
In this research project, researchers designed a comprehensive survey to understand the freeway congestion reduction practices state departments of transportation employed by using big data. This survey addressed topics such as data collection methods, data analysis techniques, big data platform usage, report creation practices, and future needs.
Researchers conducted a comprehensive literature review to gather information on thermal segregation in asphalt mixes. Various hardware systems, specifications, and previous research studies were summarized and documented to understand the existing knowledge on the subject.
Posted speed limits on Texas roadways have increased in recent years. Texas now has many miles of roadways posted at speeds of 75 mph and above. Barrier systems (e.g., guard fence, median barriers, and bridge rails) are currently tested and evaluated at a design impact speed of 62 mph. The performance limits of existing barriers are not known. Some
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Evaluating the numerous types of traffic control devices (TCDs) newly available and installed across Texas roadways is a key for the Texas Department of Transportation (TxDOT) to maintain roadway safety and proper performance of TCDs. Evaluations are also needed in order to cost-effectively implement new devices and technologies for continual impro
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This implementation project aimed to validate the results of a previous project (0-5665) by determining the rumble strip depth that can provide adequate protection to the markers while also still being visible to road users. The research team identified additional sites to deploy embedded markers in rumble strips. Two marker types (low profile mark
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The objective of this project was to develop a median opening protection system (MOPS) suitable for implementation in sloped medians between parallel bridges. One primary goal was to use currently available technologies to speed implementation. The MOPS was intended to prevent motorists from experiencing these roadway departure crashes between para
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The researchers developed the Asphalt Mixture Automated Testing System with Zero Intervention (AMAZE), shown in Figure 1. The AMAZE includes five units: • An air voids measurement unit. • A specimen storage unit. • Two temperature conditioning units, one for room temperature and the other for high temperature (e.g., 50 °C). • A material testing loa
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From 2010 to 2019, approximately 1700 wrong-way driving (WWD) crashes occurred in Texas on controlled-access highways (e.g., freeways and interstates). On average, about 170 WWD crashes occurred each year, and 10 percent resulted in a fatality. To reduce the number of wrong-way (WW) maneuvers and associated crashes on Texas freeways, the Texas Depa
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Texas Department of Transportation (TxDOT) annually encounters a substantial number of claims and change orders that have a detrimental effect on project costs and schedules. State Departments of Transportation (DOTs) spend approximately $10 million annually on geotechnical-related change orders, accounting for about 7% of the total expenditures as
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The design, construction, and maintenance of off-system bridges vary across local governments (cities and counties), often resulting in inferior performance compared to bridges managed by state highway agencies. Limited knowledge of local government practices hinders understanding of the factors contributing to these deficiencies and poses challeng
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The Illinois Department of Transportation (IDOT) continues to use a variety of reclaimed and recycled materials in highway construction. Recycled materials are used in highway construction to supplement aggregates, concrete, hot-mix asphalt (HMA), steel, and sealants, as well as for soil modification and pavement markings. This report summarizes th
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Over the last 85 years, engineers and researchers have tweaked and analyzed every minute detail of roadway design with one goal: optimizing vehicular speed. Although the industry has been looking seriously at design for other modes since the late 1980’s, the vast majority of the money and energy has been poured into examining every nuance and detai
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The current focus on promoting sustainability in the United States transportation infrastructure has led to adopting Diverse, Modern, and Unconventional Intersections and Interchanges (DMUII) to improve traffic flow while ensuring safety. However, the adoption of DMUII designs presents challenges, including a learning curve for the public and contr
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Truck platooning—wirelessly linking two or more trucks to travel in a closely spaced convoy—is federally promoted to save fuel, improve the environment, and improve traffic operations. Platooning places trucks much closer than current design codes anticipate. While this strategy can provide higher fuel efficiency, it also can potentially overload s
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