Under the Moving Ahead for Progress in the 21st Century Act, state departments of transportation are required to report travel time reliability and set performance targets for interstate and non-interstate National Highway System facilities. Although several Virginia Transportation Research Council studies have analyzed and predicted travel time re
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Stopped traffic on freeways poses safety and operational concerns to drivers, transportation agencies, construction and maintenance contractors, and enforcement and emergency service personnel. Safety issues relate to driver ability to make gradual transitions from freeway speeds to stopped conditions without erratic maneuvers or crashes. Operation
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A major safety concern on freeways is traffic flowing at normal speed encountering unexpected slow or stopped traffic. Traffic can be queued due to recurrent congestion, work zones, or collisions and/or other incidents. Drivers encountering queues are often faced with rapidly changing conditions in terms of queue length, sight distance to the end-o
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The ultra-low-volume roads guide is designed to provide guidance for the construction of roadways in rural, isolated, Indigenous, or tribal areas with less than 100 average daily trips (<100 ADT). These roads serve a unique purpose in their communities and warrant special considerations in their design. This guide enumerates design guidelines and c
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This paper presents a comprehensive comparative analysis of the primary perception technologies, LiDAR, Radar, Camera, and Sonar, that underpin modern intelligent transportation systems and autonomous vehicles. While numerous studies have examined individual sensor technologies, this paper's primary contribution lies in its holistic, cross-modal an
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Worldwide container demand has increased significantly over the past decade, due to growing international trade and the introduction of larger containerships on certain trade routes. The Texas Department of Transportation thus contracted the Center for Transportation Research at the University of Texas, Austin to examine containerized freight movem
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Peak-streamflow frequency estimates are needed for flood-plain management; for objective assessment of flood risk; for cost-effective design of dams, levees, other flood-control structures; and for design of roads, bridges, and culverts. Peak-streamflow frequency represents the collective peak streamflow for recurrence intervals of 2, 5, 10, 25, 50
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Field laboratory experiments and numerical simulations were used to explore the question of estimating time of concentration for regions with negligible slope. Current methods for estimating time of concentration generally have the slope of the land surface in the denominator of the functional relationship. This means that as slope decreases to zer
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Some of the most prevalent cases of distress that pavement maintenance forces will encounter in expansive soil environments are roughness, longitudinal cracking, and structural deterioration. This report describes the findings from an extensive literature search, a multi-district survey, numerous field site investigations, and a laboratory testing
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The Texas Department of Transportation (TxDOT) is increasingly using nondestructive testing (NDT) for structural evaluation of pavements used in design and rehabilitation selection procedures. The Falling Weight Deflectometer (FWD) is currently the main structural evaluation tool. The Ground Penetrating Radar (GPR) has been introduced to supplement
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Research Project 0-4381, entitled “Develop an Automated System for Updating Pavement Layer Data,” is intended to develop the appropriate mechanism and the corresponding algorithms that can be used to build an automated relationship between the pavement structure of the layer database and other potential source(s) of pavement layer information at th
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Research Project 0-4381, entitled “Develop an Automated System for Updating Pavement Layer Data,” is intended to develop the appropriate mechanism and the corresponding algorithms that can be used to build an automated relationship between the pavement structure of the layer database and other potential source(s) of pavement layer information at th
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Nondestructive testing devices have been utilized for the last 50 years to assess the structural condition and bearing capacity of existing or newly constructed pavement systems. A variety of devices have been developed to measure the deformation (deflection) of a pavement due to an applied load. Currently, the most commonly used nondestructive tes
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This guide familiarizes users with the geographic information system (GIS)-based platform for vehicle age distribution and vehicle miles traveled (VMT) distribution, including installation instructions, system and program requirements, and important guidelines for use of the software package.
The report documents an economic design study to determine the best alternatives for rapid and economical replacement of bridges in rural locations. Two lane simple span bridges with spans up 100 feet were considered. A steel bridge using rolled W sections with either metal grid deck or a composite cast in place concrete deck was found to provide a
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Intersections are an important part of a highway facility because the efficiency, safety, speed, cost of operation, and capacity of the facility depend on the intersection design to a great extent. Each intersection involves through- or cross-traffic movements on one or more of the highways and may involve turning movements between these highways.
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The number of trucks on many highways in Texas and across the nation has increased to the point that special or unique roadway design treatments may be warranted. Increases in truck traffic have resulted from increases in time-sensitive freight (e.g., just-in-time deliveries), the North American Free Trade Agreement (NAFTA), and until recently a ro
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For the majority of the Texas highways the granular base layer is the main structural component of the pavement system. Project 0-4358 was initiated to provide Texas Department of Transportation (TxDOT) guidelines to improve its base specifications in order to better withstand the demands of future traffic loads. This report provides the results of
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The objective of this study was to evaluate the engineering properties of two local unbound granular materials, with a focus on the gradation and especially the percentage of fines (aggregate passing the No. 200 sieve). Two materials were obtained from two local quarries for this purpose. The percentage of fines was varied in these mixtures. Each m
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The objective of this project was to develop two aesthetically pleasing and crashworthy bridge rails for use by the Texas Department of Transportation (TxDOT). Texas Transportation Institute and TxDOT worked cooperatively to conceptualize several aesthetically pleasing rail designs. Researchers performed full-scale crash tests in accordance with Na
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United States Department of Transportation
Baghersad, Mahdi