Live Webcast Event : December 6, 2018 at 11:00 AM EST TRB Special Report 329: Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future explores pending and future federal investment and policy decisions concerning the federal Interstate Highway System. Congress asked the committee to make recommendations on the “features, standards, capacity needs, application of technologies, and intergovernmental roles to upgrade the Interstate System” and to advise on any changes...

TRB has released a prepublication version of Critical Issues in Transportation 2018. In this report, which is updated periodically by the TRB Executive Committee, a series of challenging questions are posed to explore issues and opportunities that may arise 10 to 20 years into the future. These questions, 63 in all, have been organized into 12 topic areas and provide a way to frame future areas of research, policy analysis, and debate. Critical issues identified in this report deserve attention because o...

TRB's Airport Cooperative Research Program (ACRP) latest Impacts on Practice explores the impact ACRP Synthesis 39 : Airport Wildlife Population Management has had on integrated wildlife management plans at airports. A wildlife biologist at Orlando International Airport utilized this report to develop a holistic approach to mitigating bird strikes with a specific species of heron that thrives in the Florida wetlands. This document also provides guidance for dealing with threatened and endangered species,...

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 aggregate (VMA) requirements that complement the Superpave system. Performance testing ties together these approaches th...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 890: Using Recycled Asphalt Shingles with Warm Mix Asphalt Technologies documents the development of a design and evaluation procedure that provides acceptable performance of asphalt mixtures incorporating warm mix asphalt (WMA) technologies and recycled asphalt shingles (RAS)—with and without recycled asphalt pavement (RAP)—for project-specific service conditions. Since the introduction of the first WMA technologies in the ...

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 pavement layers can be initiated at the pavement surface and propagate downward through the asphalt layer. However, t...

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 functional condition of an existing highway system and slowing deterioration. Additionally, the guide identifies...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 878: Validation of the Louisiana Interlayer Shear Strength Test for Tack Coat evaluates and validates a test method to determine the interlayer shear strength of asphalt pavement layers. The report includes three appendices documenting the field project checklist, photos of existing pavement distress in two states, and a summary of test data from field projects.

TRB's E-Circular 234: Relationships of Laboratory Mixture Aging to Asphalt Mixture Performance summarizes the results from TRB Session 462: Relationship of Laboratory Mix Aging to Asphalt Mixture Performance, which was held during the 2016 TRB Annual Meeting. This circular includes four papers on addressing laboratory mix aging and explore handling asphalt mixtures at a production facility, varying the lab mix conditioning, and capturing situations found in the field.

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 projects. Sixteen case examples were reported to illustrate successful projects conducted under a variety of scenar...