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.
A retrofit design was developed and evaluated to improve safety for motorcyclists impacting guard fence systems. Finite element computer simulations were used to evaluate and optimize the crashworthy performance of the design for motorcyclist and vehicle impacts. Full-scale crash tests were conducted to verify the performance of the system for moto
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Difficulties can arise when constructing noise walls and retaining walls due to utility conflicts, construction phasing, and inadequate access. The goal of this research was to provide guidance on the sequencing and placement of noise walls and retaining walls. The research included examining noise and retaining wall selection, standards and specif
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The project focused on two main objectives: • Determining if a filter is necessary between the riprap layer and the underlying soil and then recommending design and installation guidelines for riprap filters (granular and geosynthetic). • Examining issues related to placing riprap on an abutment or riverbank slope and the associated stability of th
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This research documented key challenges and developed and tested procedures for data collection and processing, with a focus on traffic incident management (TIM) activities such as crash reconstructions. The research included a review of historical crash data trends in Texas, simulation of the effect of environmental factors on the quality of photo
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The strut-and-tie method (STM) is a design method intended to provide realistic strength and detailing requirements for deep structural members subjected to non-linear distribution of strain by considering idealized flow of internal forces. Axially loaded concrete struts and ties are used to represent the compression and tension fields in structura
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Full-depth reclamation (FDR) is the main approach used across Texas to rehabilitate thin roadways that are structurally damaged. In the FDR process, the existing surface and base materials are pulverized, mixed together, and treated with a stabilizer. The compacted treated base then receives a final surfacing. The stabilizers historically used by t
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The current motor fuel tax (MFT) system in the US does not generate sufficient revenue for infrastructure development. To make up for the lack of revenue and to keep up with expenditures, states have begun to explore alternatives such as mileage-based user fees (MBUF). Using federal and state level data and Pennsylvania as a case study, the authors
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The Massachusetts Department of Transportation (MassDOT) identified the need to build safety analysis tools into the recently-developed Interactive Mapping Portal for Analysis and Crash Tracking (IMPACT) Crash Data Portal. MassDOT worked with highway safety stakeholders to summarize their needs then developed four tools to be added: Crash-Based Net
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The Massachusetts Department of Transportation (MassDOT) identified the need to build safety analysis tools into the recently-developed Interactive Mapping Portal for Analysis and Crash Tracking (IMPACT) Crash Data Portal. MassDOT worked with highway safety stakeholders to summarize their needs then developed four tools to be added: Crash-Based Net
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This study examines the need for intermediate diaphragms (IDs) and lateral support on low skew, low curvature prestressed concrete (PC) bridges while in-service and under construction. AASHTO beam, bulb tee, and spread box beam sections across a variety of span lengths and girder spacings were considered. To examine the in-service effect of IDs on
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Across North Carolina, the North Carolina Department of Transportation (NCDOT) provides transportation services for a variety of functions and uses. Customer satisfaction is identified as an NCDOT priority as part of the department’s Strategic Plan. Since 2015, NCDOT has measured customer service through a statewide survey focused on asking custome
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Carpooling is often promoted as a mode to reduce traffic congestion and vehicle miles traveled in road networks. This project develops a game-based mode-choice model for the morning commute involving carpooling supported by a ridesharing platform. In the model, commuters travel from homes in the suburb (Origin) to offices in downtown (Destination)
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Nearly 1 in 5 people in the US have a disability (more than 57 million) (U.S. Census Bureau), and people with disabilities use the automobile as a travel mode at significantly lower rates than people without disabilities (Bureau of Transportation Statistics). For example, people aged 18 to 64 with disabilities make 28% fewer trips per day (2.6 v. 3
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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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Heavy-duty diesel trucks (HDDTs) are significant contributors of fine particulate matter (PM2.5) and nitrogen oxides (NOx) emissions. As a result, communities with a large amount of truck traffic often experience elevated levels of diesel-related air pollution. One strategy for mitigating the air pollution impacts of truck traffic, called low expos
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From 2010 to 2020, transportation agencies have increasingly used roadside dynamic message signs (DMS) to display safety messages. Despite their widespread use, evaluations as to potential impacts on driver behavior, and the resultant impacts on traffic crashes has been very limited. This study evaluated the use of DMS to display safety messages le
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Diverse plantings along freeway roadsides can be beneficial to surrounding areas in many ways, such as improved driver safety, increased biodiversity, and improved aesthetics. Unfortunately, establishing these plantings can be difficult for a variety of reasons. To improve the success of future plantings, the authors investigated the impacts of sit
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This document describes the Concept of Operations (ConOps) for the New York City Department of Transportation (NYC) Connected Vehicle Pilot Deployment (CVPD) Project. This ConOps describes the current state of operations, establishes the reasons for change, and defines the future system in terms of functions/features and supporting operations. It i
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The Concept of Operations (ConOps) document will serve as the guiding document for the Health Connector Phase 1 planning activities, and subsequent deployment and operations and maintenance (O&M) activities in Phases 2 and 3. This document will be used to communicate overall quantitative and qualitative system characteristics to the end user, devel
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This document describes the System Requirements Specification (SyRS) for the New York City Department of Transportation (NYC) Connected Vehicle Pilot Deployment (CVPD) Project. This SyRS describes the results of the definition of need, the operational concept, and system analysis tasks. It also conveys the requirements that are geared towards satis
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