State transportation agencies are increasingly tasked with doing more with less in managing highway transportation networks. The TRB National Cooperative Highway Research Program's NCHRP Research Report 923: Workforce Optimization Workbook for Transportation Construction Projects provides state transportation agencies with guidance to identify their construction staffing needs and how to best a...

Scaling loose rocks from slopes adjacent to highways is a simple and effective measure for temporarily reducing the risk of rockfall potential on naturally occurring bedrock outcrops and highway rock–soil cuts. However, the current practice in estimating scope of work and contracting rock scaling projects are inconsistent from agency to agency. Many owners and transportation agencies conduct sc...

A long-existing challenge to the bridge engineering community is how to achieve fast construction while ensuring a structure’s integrity and sustainability. The TRB Highway Innovations Deserving Exploratory Analysis Program's IDEA Final Report 188: A Class of V-Connectors for Bridge Deck-Pier and Pier-Footing Joints with the Combined Advantage of Integrated Design and Seismic Isolation while En...

The TRB Centennial Book is available for purchase in ebook or print format. In The Transportation Research Board, 1920–2020: Everyone Interested Is Invited , author Sarah Jo Peterson tells the story of how people and institutions created and have continued to shape TRB. In a compelling narrative accompanied by more than 150 images exploring the history of transportation and research, she argues...

A programmatic approach to sustainable materials procurement in highway construction may be better than one-off attempts. For now, there is little guidance on procuring sustainability in highway construction and sustainability is not as important as cost or schedule. The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 262: Sustainable Highway Construction describes t...

Sustainability is often an element that informs decisions made during the planning, programming, and design phases of highway construction projects. However, the construction phase of a highway project is also an opportunity to advance sustainability. The TRB National Cooperative Highway Research Program's NCHRP Research Report 916: Sustainable Highway Construction Guidebook provides clear and ...

The Wisconsin DOT issues both single- and multi-trip permits for Oversize–Overweight (OSOW) vehicles. As the number of OSOW vehicle permits issued in Wisconsin have increased in recent years, the management and analysis of OSOW permit data has become more labor-intensive and time-consuming. This "Research Pays Off" feature in  TR News edition 324 (November-December 2019), by Hani Titi, Nic...

This article is adapted from The Transportation Research Board, 1920–2020: Everyone Interested Is Invited , to be published by the National Academies Press in January 2020. TRB can be best understood as an infrastructure—one that people purposely designed, carefully constructed, and devotedly maintained to share and strengthen knowledge about transportation. The core missions and structures tha...

The November-December 2019 issue of TR News - with a focus on climate change resilience - is available in hard copy and digital copy for subscribers. For those who are not subscribers, the table of contents is available. Other feature articles in the issue include ones on the history of both TRB and transportation in general and a preview of the TRB Annual Meeting slated for January in Washingt...

About $1.5 trillion will be spent globally on airport infrastructure by 2030, a ccording to the International Air Transport Association.  Most of that enormous amount of money will be spent on projects that must be constructed without disrupting airport operations. Given the focus on schedule and on the cost of failing to complete the construction during the periods of planned outages, the...

Concrete is a porous material that allows materials to move through it. The number of pores connected in the concrete, also known as the permeability, influences the ability of fluids to penetration the concrete. And this permeability parameter is an important transport mechanism for freeze-thaw damage, corrosion, alkali silica reaction, and sulfate attack. The TRB Innovations Deserving Explora...

Global business and tourism depend heavily on the efficient operation of airports and movement of passengers, baggage, and cargo across many areas. With increasing demand and connectivity requirements for airports comes the need for more sophisticated simulation and modeling tools to validate design assumptions. Furthermore, airport design and planning decisions have significant impacts on poli...

The performance of flexible and rigid pavements is known to be closely related to properties of the base, subbase, and/or subgrade. However, some recent research studies indicate that the performance predicted by this methodology shows a low sensitivity to the properties of underlying layers and does not always reflect the extent of the anticipated effect, so the procedures contained in the Ame...

TRB’s Technical Activities Division has released Transportation Research Circular E-C249: Key Elements of Construction Quality Assurance for Implementation, presenting a synopsis of " Quality Assurance: There’s Value in the Basics," held at the 2018 Annual Meeting of the Transportation Research Board. In this session, four speakers with a range of perspectives—the Federal Highway Administration...

The uses and levels of maturity of five advanced technology areas visualization and modeling, interconnected technologies, safety technologies, instrumentation and sensors, and unmanned aircraft systems in transportation highway construction projects are documented in TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 534: Emerging Technologies for Construction Delivery. The ...

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 537: Impact of Asphalt Thickness on Pavement Quality documents transportation agency policy for lift thickness and minimum compaction requirements on resultant asphalt pavement quality. To achieve expected pavement performance, it is important that asphalt concrete (AC) have adequate density. A critical factor in achieving th...

TRB Special Report 330: Performance of Bridges That Received Funding Under the Innovative Bridge Research and Construction Program, examines the results of a federal program to promote innovation in highway bridge construction. The report provides recommendations to Congress on how the installed and life-cycle costs of bridges could be reduced through the use of innovative materials and technol...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Report 908: Acceptance Criteria of Complete Joint Penetration Steel Bridge Welds Evaluated Using Enhanced Ultrasonic Methods presents guidelines for evaluating complete joint penetration (CJP) welds in steel bridges and proposes modifications to the American Association of State Highway and Transportation Officials (AASHTO)/Am...

TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 536: Bridge Demolition Practices documents practices used by bridge owners to manage and administer bridge demolition in construction projects. Each year hundreds of bridges are rebuilt or are entirely replaced as part of highway construction projects. Bridge reconstruction or replacement work often entails demolition of part...

TRB’s National Cooperative Highway Research Program (NCHRP) Web-Only Document 260: Proposed Refinements to Design Procedures for Geosynthetic Reinforced Soil (GRS) Structures in AASHTO LRFD Bridge Design Specifications explores the effect of adopting a closely‐spaced reinforcement layout in geosynthetic‐reinforced soil structures. While research since the early 1980s has identified the benefici...

TRB's National Cooperative Highway Research Program (NCHRP) Research Report 894: Performance of Longitudinal Barriers on Curved, Superelevated Roadway Sections  presents guidance on designing, selecting, and installing longitudinal traffic barriers for curved, superelevated roadways for possible incorporation in the American Association of State Highway and Transportation Officials (AASHTO...

TRB has released Critical Issues in Transportation 2019 . 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 analys...

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 up...

The latest edition of Research Pays Off explores how to evaluate the impact of transportation projects on residential subdivisions. 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 items of interest to the transportation community, research pays off articles that...

The full edition of the July–August 2018 TR News is now available. This edition 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 m...

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 i...

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) 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 pave...

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) Innovations Deserving Exploratory Analysis (IDEA) Final Report 186: Development of an Electrical Probe for Rapid Assessment of Ground Improvement explores new technologies that can be used in soil improvement. Soil improvement has numerous applications in transportation construction, including embankment stabilization, underpinning bri...