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...

TRB’s Transportation Research Record: Journal of the Transportation Research Board has released 16 early access papers addressing pavements, including: Intelligent Compaction for Quality Control and Acceptance for Soil and Base Compaction through Statistical Analysis ( link ) Comparing Traffic Speed Deflectometer and Falling Weight Deflectometer Data ( link ) Time-Series Review of Highway Performance Monitoring System Data ( link ) Development of a Structural Capacity Prediction Model Based on Traffic Sp...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 526: Inertial Profiler Certification for Evaluation of International Roughness Index determines the state of practice of certification of inertial profilers at the national and international levels. Inertial profilers are used to collect the repeatable and reproducible road profiles analyzed to calculate a smoothness or ride quality index, the most common of which—the International Roughness Index (IRI) — is a performance measure that ...

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, restoration, or rehabilitation (3R) project. The approach uses the performance of the existing road in estimating t...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 524: Aggregate Quality Requirements for Pavements Aggregate Quality Requirements for Pavements documents transportation agency requirements for the quality of aggregates for various pavement types. Constructing and maintaining pavements requires an abundant and dependable supply of quality aggregates. Aggregate comes from a wide range of materials, including quarried rock, sand, and gravel, and materials such as slag, reclaimed asphalt...

TRB's National Cooperative Highway Research Program (NCHRP) has released a pre-publication, non-edited version of Research Report 890: Using Recycled Asphalt Shingles with Warm Mix Asphalt Technologies.  The report 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 condi...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 877: Performance-Based Mix Design for Porous Friction Courses presents a proposed mix design method for porous asphalt friction course (PFCs). PFCs have been used in the United States for many years. Their open aggregate gradations and resultant high air void contents provide PFCs with the ability to quickly remove water from the surface of a roadway, thus reducing the potential for vehicles to hydroplane and improving skid resis...

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 departure crashes. This type of crash occurs after a vehicle crosses an edge line or centerline or otherwise leaves th...

The National Cooperative Highway Research Program (NCHRP) Innovations Deserving Exploratory Analysis (IDEA) Final Report 193: DART Field Validation and Prototype Refinement documents a study to validate a field-ready prototype of the Duomorph Asphalt Rheology Tester (DART) as a low-cost and easy-to-use asphalt binder testing device. The DART system has the potential to provide a cost-effective way to monitor the uniformity or specification compliance of asphalt binder samples at various points along its ...