Transportation Research E-Circular 237: Innovations in Asphalt Mixture Design Procedures explores the fundamentals of asphalt mix design for improved durability and performance. Based off of presentations made at TRB's 95th Annual Meeting, the document examines presentations that cover ways to incorporate more binder into the mix with trials that modify the air void and void in mineral aggregat...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 257: A Mechanistic–Empirical Model for Top–Down Cracking of Asphalt Pavements Layers develops a calibrated mechanistic-empirical (ME) model for predicting the load-related top-down cracking in the asphalt layer of flexible pavements. Recent studies have determined that some load-related fatigue cracks in asphalt pavem...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 858: Quantifying the Effects of Preservation Treatments on Pavement Performance presents a proposed framework that uses performance measures to quantify the changes in pavement performance in terms of condition, service life, and life-cycle costs. Pavement preservation provides a means for maintaining and improving the ...

The latest edition of Research Pays Off explores the Georgia Department of Transportation (DOT)'s use of alternative delivery methods to compress and accelerate the delivery of projects from engineering through construction through public–private partnerships (PPPs) and design–build (DB) methods.This article discusses the legislation that allowed Georgia DOT to build partnerships with private f...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 530: Construction and Rehabilitation of Concrete Pavements Under Traffic identifies practices from projects representing a wide range of conditions and techniques. The current state of the practice in constructing or rehabilitating concrete pavements under traffic relies primarily on a few high-profile and well-documented pro...

A featured article in the July-August 2018 issue of the TR News investigates how risk is addressed in both the traditional project delivery method and in alternative project delivery methods used by departments of transportation across the country.  The TR News is TRB's bimonthly magazine featuring timely articles on innovative and state-of-the-art research and practice in all modes of tra...

A featured article in the July-August 2018 issue of the TR News examines the latest application and implementation of alternative contracting methods for faster project delivery of transportation infrastructure. The TR News is TRB's bimonthly magazine featuring timely articles on innovative and state-of-the-art research and practice in all modes of transportation. It also includes brief news it...

The July–August issue of TR News examines 20 years of research and TRB activities on alternative contracting methods (ACM) and success stories from implementing research innovations. Explored are pioneering tools and contracting techniques used by state departments of transportation such as Georgia and Colorado, along with tested project delivery methods, selection tools for transit, internatio...

TRB’s Transportation Research Record: Journal of the Transportation Research Board has released 24 early access papers addressing maintenance and preservation, including: Study on the Day-Based Work Zone Scheduling Problem in Urban Road Networks Based on the Day-to-Day Traffic Assignment Model ( link ) Development of a Pavement Marking Life Cycle Cost Tool ( link ) Developing Guidelines for Epo...

TRB's National Cooperative Highway Research Program (NCHRP) has released a pre-publication, non-edited version of Research Report 876: Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects. The report presents an approach for estimating the cost-effectiveness of including safety and operational improvements in a resurfacing, res...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 517: Corrosion Prevention for Extending the Service Life of Steel Bridges documents and describes the current practice for corrosion prevention of steel bridges. This report provides information on choosing materials and coatings to prevent corrosion, and documents ways to develop an effective maintenance plan for newly const...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 515: Practices for Preventing Roadway Departures identifies and summarizes practices being used by state departments of transportation (DOTs) to prevent roadway departure crashes and to identify the data-driven advantages and disadvantages of these practices. More than half of all traffic fatalities result from roadway depart...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 251: Spot Painting to Extend Highway Bridge Coating Life: Volume 2: Research Overview documents the evaluation method for a guidance document that provides approaches for employing spot painting in a cost-effective, safe, and environmentally compliant manner. Bridge coatings are the primary means of corrosion pro...

TRB's National Cooperative Highway Research Program (NCHRP) Web-Only Document 251: Spot Painting to Extend Highway Bridge Coating Life: Volume 1: Guidance provides approaches for employing spot painting in a cost-effective, safe, and environmentally compliant manner. Bridge coatings are the primary means of corrosion protection for steel bridges in the United States. Most bridge coatings tend t...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 871: Long-Term Aging of Asphalt Mixtures for Performance Testing and Prediction presents a proposed standard method for long-term laboratory aging of asphalt mixtures for performance testing. The method is intended for consideration as a replacement for the method in AASHTO R 30, “Mixture Conditioning of Hot Mix Asphalt...

To keep pace with accelerating rate of research distribution, the Transportation Research Record: Journal of the Transportation Research Board is now publishing articles as soon as they are finalized. The latest papers to be published are as follows: Use of a Laser Diffractometer to Obtain the Particle Size Distribution of Fine-Grained Soils Interstate Speed Profiles Conditioning and Testing Pr...

TRB's E-Circular 228: Rebuilding and Retrofitting the Transportation Infrastructure documents the presentations from a conference of the same name held in Washington, D.C., in September 2017. This meeting was the 11th in a series of Spotlight Conferences funded by the U.S. Department of Transportation’s (DOT) Office of the Assistant Secretary for Research and Technology, University Transportati...

TRB's National Cooperative Highway Research Program (NCHRP) latest Research Topic Highlights explores solutions for roadway tunnels. It summarizes the results of several research projects that has framed the problems and mitigation strategies associated with tunnels. Included are summaries of tunnel inspection, rehabilitation, and preservation; tunnel design; and tunnel safety and security.

The full edition of the July–August 2017  TR News  magazine is now available.  Moving research into practice is the theme of feature articles in this edition. Authors describe today’s successes, present a systematic approach that has proved effective at a state department of transportation, describe federal programs encouraging innovations at the state level, discuss initiatives ...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 863: Material Properties of Cold In-Place Recycled and Full-Depth Reclamation Asphalt Concrete  presents procedures for determining material properties of cold-recycled asphalt mixtures for input to pavement structural design programs. Highway agencies are placing increasing emphasis on sustainability, recycling, a...

TRB's Airport Cooperative Research Program (ACRP) latest Impacts on Practice discusses how Harrisburg Airport (MDT), part of the Susquehanna Area Regional Airport Authority in Harrisburg, Pennsylvania applied results of ACRP Report 92 : A Guidebook to Creating a Collaborative Environment Between Airport Operations and Maintenance. The tools contained in helped MDT employees collaborate across t...

The full edition of the May-June 2017 TR News is now available. This edition explores the role of transportation in economic development. Articles feature information about benefit-cost analysis, freight production models, transportation satellite accounts, and right sizing strategies. The TR News is TRB's bimonthly magazine featuring timely articles on innovative and state-of-the-art research ...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 857: Performance-Related Specifications for Pavement Preservation Treatments presents guidelines for use in preparing performance-related specifications (PRS) for pavement preservation treatments and, if desired, determining pay adjustment factors. Although PRS have been used for the construction of pavements, their use...

TRB's Innovations Deserving Exploratory Analysis (IDEA) Program Safety 27: Field Evaluation of Ballast Fouling Conditions Using Machine Vision introduces a machine vision-based inspection system to assess ballast degradation levels for an in-service rail track. This system incorporates an approach to ballast sampling, procedures for image acquisition of horizontal and vertical ballast cross sec...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 859: Consequences of Delayed Maintenance of Highway Assets presents a process for quantifying the consequences of delayed maintenance of highway assets that considers the asset preservation policy, the maintenance and budget needs, and the analyses of delayed maintenance scenarios. This process considers delayed mainten...

TRB's National Cooperative Highway Research Program (NCHRP) Innovations Deserving Exploratory Analysis (IDEA) has released Final Report 181: Development of Small Specimen Geometry for Asphalt Mixture Performance Testing. The use of small specimen geometries in Asphalt Mixture Performance Tester (AMPT) offer a means to measure as-built pavement layers. Small specimen geometries may improve the e...

TRB's Airport Cooperative Research Program (ACRP) Synthesis 85: Alternative Fuels in Airport Fleets is designed to assist airport operators in analyzing complex procurement, operational, and environmental decisions when considering alternative fuels in airport fleets. Airports own and contract fleets to transport passengers, staff, and goods by on- and off-road vehicles. Although most transport...

The latest of TRB's National Cooperative Highway Research Program (NCHRP) Ready Results explores new technologies and practices to inspect culvert and storm drains. The manual assists transportation agencies with incorporating culverts into modern asset management systems—a move that allows agencies to improve the way they prioritize rehabilitation activities and more clearly demonstrate the ne...

The latest of TRB's National Cooperative Highway Research Program (NCHRP) Ready Results summarizes nondestructive evaluation (NDE) methods for assessing the condition of in-service post-tensioning and stay cable systems. Post-tensioned (PT) girder bridges and stay cable bridges pose a challenge to bridge inspectors because steel tendons used as the primary structural support in these bridges ar...

A featured article in the May-June 2017 issue of the TR News examines how to develop appropriate evaluation frameworks that account for the integration of new technologies into the infrastructure in order to accurately value the current highway system. The TR News is TRB's bimonthly magazine featuring timely articles on innovative and state-of-the-art research and practice in all modes of trans...