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.
The primary objective of the research was to help FDOT successfully implement and optimize the AASHTOWare BrM software by recalibrating its essential analytical models—such as deterioration, risk, cost, and data translation tools—so the software can more accurately forecast bridge performance, support decision-making, and satisfy federal requiremen
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The objective of the research was to identify what further research is needed to use larger FRP bars in waterline pile cap footings, develop material acceptance criteria and design specifications for No. 11 glass FRP bars, and create design examples to help implement these bars in practice. Additionally, the study provided recommendations for futur
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The objective of this project was to determine appropriate screening thresholds for tests that assess concrete durability in extremely aggressive chloride and sulfate environments. Specifically, the research aimed to recommend threshold values for bulk and surface resistivity tests (based on AASHTO TP 119 and T 358) for chloride durability, and for
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Successful transportation safety messages are only effective if travelers can comprehend the notices. However, one method of safety messaging, text-only messages, can be challenging for non-native English speakers and slow-reading populations, such as older adults. The addition of graphics can potentially improve message comprehension, but their ef
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The primary objective of this study was to investigate the feasibility of using lignin, an environmentally friendly biopolymer, for sustainable protection of Kansas roadsides against wind and rainfall erosion during the critical stage of construction that occurs prior to the emergence of a vegetative cover. Results from laboratory-scale experiments
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This study delivers a Michigan-specific mechanistic-empirical framework for rehabilitation pavement design by locally calibrating PMED V2.6 across all major MDOT rehabilitation fixes, including asphalt over asphalt/concrete/rubblized concrete/crushed asphalt, and concrete over asphalt/concrete. Using 14 field projects, FWD, GPR, LWD, and field core
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Traffic microsimulation enables practitioners to model the movement and interactions of individual vehicles, providing a level of detail not achievable with macroscopic or deterministic approaches. Microsimulation replicates vehicle-to-vehicle and driver-to-driver interactions under a wide range of traffic and geometric conditions. This makes it es
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Open-graded granular backfill materials are widely used as retaining wall backfill due to their high shear strength, high permeability, ease to handle, and compaction characteristics. However, the current Tennessee Department of Transportation (TDOT) provisions assume a conservative angle of internal friction for backfill materials. The objective o
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In 2018, the Virginia Department of Transportation (VDOT) implemented the American Association of State Highway and Transportation Officials’ (AASHTO) AASHTOWare-ME version 2.2.6 as the pavement design methodology for new, reconstruction, and lane-widening projects, including interstate, primary, and secondary routes with annual average daily traff
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Waste plastic (WP) is a growing environmental concern due to its non-biodegradable nature, large-scale production, and harmful impact on natural resources. With nearly 75% of WP in the U.S. ending up in landfills, effective recycling strategies are urgently needed. In parallel, the limited availability of natural aggregates highlights the need for
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The American Association of State Highway and Transportation Officials (AASHTO) and the American Welding Society (AWS) provide extensive guidance documents that govern the welding of steel bridge members; however, none of the documents provide guidance regarding the number of times a welding nonconformance can be repaired without penalty or rejecti
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Steel pipe piles are a promising alternative to traditional H-piles and drilled shafts for ALDOT bridge substructures because they can achieve high force and moment capacity and enable more efficient construction. However, current guidance on steel pipe pile–to–reinforced concrete bent cap connections is limited, and practices among state DOTs vary
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The objective of this study is to further improve and refine the recommended preferred alternative skew monitoring and detection technologies (inclinometer and encoder systems only), integrating them into the existing control system and proving their operability and long-term reliability at the Ellenders Ferry Vertical Lift Bridge.
Balanced Mix Design (BMD) represents a major advancement in asphalt pavement engineering. As a performance-driven framework, BMD integrates mix design, structural design, quality assurance/quality control (QA/QC), and performance-related specifications (PRS) to promote durable and sustainable pavements and innovations. This synthesis documents the
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The low-temperature properties of asphalt binder play a critical role in the behavior and performance of flexible pavements. Since the 1990s, the Bending Beam Rheometer (BBR) has been the standard instrument for characterizing these properties. However, BBR testing requires time-consuming sample preparation and extensive equipment maintenance. Desp
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The development of a national standard data format for two-dimensional/three-dimensional (2D/3D) pavement surface images and Artificial Intelligence (AI) Machine Learning (ML) in Computer Vision adopted by AASHTO and embraced by state DOTs has provided TxDOT the opportunity to develop new methods for automated pavement condition assessment. This re
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Temperature-induced curling and moisture-driven warping continually reshape jointed concrete pavements (JCP), altering wheel-path profiles and affecting the International Roughness Index (IRI). This report presents an integrated framework combining finite element method (FEM) analyses, artificial neural networks (ANNs), and IRI modeling to isolate
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This research investigates applying high-resolution vehicle trajectory data, derived from vehicle telematics, to facilitate freeway and arterial performance analysis in Nevada. Leveraging vehicle trajectory datasets crowd sourced through original equipment manufacturer (OEM) telematics, the research team conducted a comprehensive synthesis of commo
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This report analyzes and summarizes the changes in conflicts, user volumes, speed, travel time, and vehicle throughput before and after a multimodal safety project on N Lombard St. Results show that changes in each metric were observed in the before and after conditions. The number of persons using crosswalks decreased between 2017 and 2019 and inc
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This study presents a comprehensive evaluation of alkali-silica reaction (ASR) in concrete mixtures, focusing on the performance-based specifications and the critical role of supplementary cementitious materials (SCMs) in mitigation. A modified version of American Association of State Highway and Transportation Officials (AASHTO) T380 was developed
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