TRB’s National Cooperative Highway Research Program (NCHRP) Report 718: Fatigue Loading and Design Methodology for High-Mast Lighting Towers provides criteria for the fatigue design of high-mast lighting towers. The report also includes a series of proposed revisions with associated commentary to the fatigue design provisions of the American Association of State Highway and Transportation Offic...

Roundabouts have seen unprecedented growth across the United States, from just a handful a decade ago to more than 2,000 and counting. National guidance had to keep pace with the needs of states and communities planning and implementing roundabouts, and NCHRP took a lead role.

On March 16, 2012, TRB’s Long-Term Bridge Performance (LTBP) Committee sent its first letter report to Victor Mendez, administrator of the Federal Highway Administration (FHWA). The committee provides advice and assistance on the conduct of the LTBP program, which is designed to collect research-quality data on a large representative sample of in-service U.S. highway bridges and to analyze thes...

In regions across the nation, bridge engineers know that the next major seismic event is coming—maybe tomorrow, maybe centuries from now. DOTs have the critical charge of designing for earthquakes and protecting the lives of travelers.

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 187: Seismic Design of Geosynthetic-Reinforced Soil Bridge Abutments with Modular Block Facing explores design methods and construction guidelines for using geosynthetic-reinforced soil (GRS) systems in bridge abutments in seismically active regions. The report focuses on single-span, simply-supported bridges subjecte...

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 425: Waterproofing Membranes for Concrete Bridge Decks documents information on materials, specification requirements, design details, application methods, system performance, and costs of waterproofing membranes used on new and existing bridge decks since 1995. The synthesis focuses on North American practices with some info...

TRB’s second Strategic Highway Research Program (SHRP 2) has released a Renewal Products Brief, which summarizes the status of products being produced within the Renewal area of SHRP 2. The goal of Renewal research in SHRP 2 is to advance the methods and materials that transportation agencies can use to renew the nation’s vital but aging highway system even as we continue to use and live n...

TRB’s Transportation Research Record: Journal of the Transportation Research Board, No. 2251 consists of 16 papers that explore the relationships of barge bow force–deformation for bridge design, innovative vibration absorber, vibration versus deflection control for bridges with high-performance steel girders, two new retrofit combination steel and concrete bridge rail designs, and skew in brid...

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 423: Long-Term Performance of Polymer Concrete for Bridge Decks addresses a number of topics related to thin polymer overlays (TPOs). Those topics include previous research, specifications, and procedures on TPOs; performance of TPOs based on field applications; the primary factors that influence TPO performance; current cons...

TRB’s second Strategic Highway Research Program (SHRP 2) has released a project brief that provides a snapshot of SHRP 2 progress. Since its authorization in 2005, 50 pilot tests and field demonstrations have been undertaken in 24 states, 35 documents have been published, data are being collected from nearly 1000 cars in the naturalistic driving study, and five invitational work sessi...

TRB’s National Cooperative Highway Research Program (NCHRP) Report 701: Proposed Specifications for LRFD Soil-Nailing Design and Construction contains proposed specifications for the design and construction of soil-nailed retaining structures. The American Association of State Highway and Transportation Officials (AASHTO) Standard Bridge Specifications, the AASHTO Load and Resistance Factor Des...

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 181: Evaluation of Bridge-Scour Research: Abutment and Contraction Scour Processes and Prediction examines bridge-abutment scour and the effectiveness of the leading methods used for estimating design scour depth.

TRB’s National Cooperative Highway Research Program (NCHRP) Research Results Digest 363: Hydroacoustic Impacts on Fish from Pile Installation explores the prediction and mitigation of the negative impacts on fish from underwater sound pressure during pile and casing installation and removal.  Appendices A through H for RRD 363 are available online.

TRB’s National Cooperative Highway Research Program (NCHRP) Report 697: Design Guidelines for Increasing the Lateral Resistance of Highway-Bridge Pile Foundations by Improving Weak Soils examines guidance for strengthening of soils to resist lateral forces on bridge pile foundations. The report presents computational methods for assessing soil-strengthening options using finite-element analysis...

TRB’s Transportation Research Record, Journal of the Transportation Research Board, No. 2220 includes 11 papers that explore portland cement concrete exposed to automated deicing solutions; identification and tracking of highway bridge maintenance; health monitoring of prestressing tendons in posttensioned concrete bridges; bridge maintenance in New York City, New York; multicriteria bridge man...

The July-August 2011 TR News assembles feature articles exploring the state of security and critical infrastructure protection, including an assessment of U.S. infrastructure resiliency, North American perimeter security and the movement of trade, the security of bridges and tunnels, measures to protect rail and transit from attacks, the effects of piracy on the global supply chain, a...

TRB’s National Cooperative Highway Research Program (NCHRP) Report 700: A Comparison of AASHTO Bridge Load Rating Methods documents an analysis of 1,500 bridges that represent various material types and configurations using AASHTOWare™ Virtis® to compare the load factor rating to load and resistance factor rating for both moment and shear induced by design vehicles, American Association of Stat...

TRB’s National Cooperative Highway Research Program (NCHRP) Report 698: Application of Accelerated Bridge Construction Connections in Moderate-to-High Seismic Regions evaluates the performance of connection details for bridge members in accelerated bridge construction in medium-to-high seismic regions and offers suggestions for further research. The following appendixes to NCHRP Report 698 were...

TRB’s National Cooperative Highway Research Program (NCHRP) Report 696: Performance of Corrugated Pipe Manufactured with Recycled Polyethylene Content provides potential specifications for corrugated drainage pipe manufactured with recycled high-density polyethylene (HDPE). The report includes proposed draft specifications for recycled HDPE, formulations of virgin and recycled HDPE, and drainag...

TRB’s Transportation Research Record: Journal of the Transportation Research Board, No. 2212 contains 13 papers that explore acceptance of geomaterials, water jetting to mitigate defects in drilled shafts, pile load test and implementation of load and resistance factor design specifications, lateral resistance of short rock sockets in weak rock, and field testing of a batter pile group foundati...

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 418: Developing Production Pile Driving Criteria from Test Pile Data provides information on the current practices used by state transportation agencies to develop pile driving criteria, with special attention paid to the use of test pile data in the process.

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 415: Design Fires in Road Tunnels information on the state of the practice of design fires in road tunnels, focusing on tunnel fire dynamics and the means of fire management for design guidance. Note:  On September 20, 2011, the following errata was released related to NCHRP Synthesis 415.  The electronic version of...

TRB’s National Cooperative Highway Research Program (NCHRP) RRD 355: Summary of Cast-In-Place Concrete Connections for Precast Deck Systems summarizes the results of a project that developed recommended design and construction specifications and examples for the design and construction of durable cast-in-place reinforced concrete connections for precast deck systems. The project focused on syst...

TRB’s National Cooperative Highway Research Program (NCHRP) Report 683: Protocols for Collecting and Using Traffic Data in Bridge Design explores a set of protocols and methodologies for using available recent truck traffic data to develop and calibrate vehicular loads for superstructure design, fatigue design, deck design, and design for overload permits. The protocols are geared to address th...

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 177: Evaluation of Bridge Scour Research: Geomorphic Processes and Predictions explores the impact of long-term aggradation and degradation, and lateral river channel migration, on highway structures.

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 175: Evaluation of Bridge Scour Research: Pier Scour Processes and Predictions explores the current state of knowledge regarding bridge-pier scour, assesses several methods for design estimates of scour depth, examines a structured methodology for scour-depth estimation for design purposes, and highlights aspects of&n...

TRB’s Strategic Highway Research Program (SHRP 2) has released a project brief that highlights the activities taking place within SHRP 2’s Renewal focus area related to implementing innovative means to enhance the durability of bridge foundations and components; reduce the cost and time related to bridge design, construction, and repair; and optimize bridge deck inspections.

TRB’s National Cooperative Highway Research Program (NCHRP) Report 675: LRFD Metal Loss and Service-Life Strength Reduction Factors for Metal-Reinforced Systems explores the development of metal loss models for metal-reinforced systems that are compatible with the American Association of State Highway and Transportation Officials' Load and Resistance Factor Design Bridge Design Specifications. ...

The Water Science and Technology Board, part of the National Academies’ Division on Earth and Life Studies (DELS), has released a report that states that the U.S. Army Corps of Engineers-- which operates and maintains the nation's water resources infrastructure of dams, levees, locks, and navigation channels--faces a water planning paradox. According to the committee that developed the report, ...

TRB’s National Cooperative Highway Research Program (NCHRP) Report 679: Design of Concrete Structures Using High-Strength Steel Reinforcement evaulates the existing American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications relevant to the use of high-strength reinforcing steel and other grades of reinforcing...