Section 106 of the National Historic Preservation Act (NHPA) requires transportation agencies to consider the effects of their undertakings on historic resources when those undertakings are federally funded. Section 106 of the NHPA also allows for the use of Program Alternatives to tailor compliance, potentially streamlining Section 106 evaluations for commonly encountered categories of histori...

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...

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...

The past few years have seen some significant advances in concrete technology. For example, newer concrete incorporating advances in admixtures and cementitious materials has emerged. The TRB National Cooperative Highway Research Program's NCHRP Synthesis 544: Concrete Technology for Transportation Applications documents how state departments of transportation select and deploy concrete technol...

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...

The majority of instances of explicit consideration of service life design has been limited to signature bridges and other projects where extended service lives (in other words, greater than 100 years) are specified by the owner. Many state departments of transportation and other transportation agencies have recognized the importance of implementing service life design for typical highway bridg...

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...

The U.S. transportation system is developed, operated, and managed by private and public enterprises and, as of 2012, employs approximately 4.3 million people. This number is even larger when it accounts for people whose jobs are entirely dependent on the transportation system, from delivering fresh lettuce year-round to a fast response to a fire alarm to the reliable delivery of children to sc...

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...

Analysis of the erodibility of geomaterials is important for the study of problems related to soil erosion such as bridge scour, embankment overtopping erosion, and stream stability. Erodibility is the relationship between the soil erosion rate and fluid velocity or hydraulic shear stress. Since different soils have different geotechnical properties, their erosion rates vary. The TRB National C...

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...

Transit state of good repair (SGR) is a critical area within the U.S. transit industry. All transit agencies, large or small, regardless of region of the country or modes operated, face challenges in maintaining their physical assets in good repair, and many are in a situation where the funds available for rehabilitating and replacing existing capital assets are insufficient for achieving SGR. ...

Identifying the location, size, and extent of weld defects or flaws can be critical for ensuring bridge safety. Current bridge-inspection practice relies primarily on visual inspection for detecting cracks but is not capable of detecting subsurface weld defects that may develop into cracks under service loading. Other technologies such as conventional ultrasonic testing (UT) and radiographic te...

Information exchanged during the 97th Annual Meeting of the Transportation Research Board in a session titled "Relationship Between Laboratory Cracking Tests and Field Performance of Asphalt Mixtures" is captured in Transportation Research Circular E-C251: Relationship Between Laboratory Cracking Tests and Field Performance of Asphalt Mixtures . The document explores a significant amount of wor...

Traditionally, pavement management decision-making has relied on surface cracking as an indicator of structural condition. However, with early-intervention preservation activities to extend the life of pavements, surface cracks no longer are a reliable indicator of structural condition. In the past 15 years, traffic speed deflection devices (TSDDs) have been developed to measure pavement struct...

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...

Airports continually balance demands to improve infrastructure within the realities of available budgets. Green revolving funds (GRFs) offer an alternative approach for investing in projects that generate operational savings. These funds work by tracking verified cost reductions from implemented actions, and then transferring those savings to a reserve that provides capital for future qualified...

“Pavement condition data” are essential inputs to the process of managing airport pavements and ensuring safe operations. The technology available today to collect pavement condition data is considerably different from that available even 20 years ago, and new technologies are being developed and introduced into practice at a rapid pace. ACRP Research Report 203: Guidelines for Collecting, Appl...

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...

Although general aviation airports have historically been funded by federal, state, and local entities, the private sector is increasingly playing a larger role. This involvement has ranged on a continuum from service and management contracts to singular projects at airports that involve leasing mechanisms to long-term leases and the whole-scale private development of general aviation airports....

Public–private partnerships (P3s) can provide solutions to the project delivery challenges faced by state departments of transportation (DOTs) and local transportation agencies in delivering surface transportation infrastructure by aligning risks and rewards between public and private sectors, accelerating project delivery, improving operations and asset management, realizing construction and o...

Some concrete pavements commonly used at airports are susceptible to the destructive effects of alkali-silica reaction ( ASR).  The presence of ASR on concrete pavements can have a devastating effect on pavement performance, not only in terms of reduced functionality, but also in terms of shortened service lives.  The focus of  ACRP Synthesis 96:   Practices to Mitigate Alka...

TRB’s Technical Activities Division has released Transportation Research Circular E-C248: 12th International Conference on Low-Volume Roads, highlighting topics including road surfaces, geotechnology, cold regions and climate change, pavement management, planning and economics, unpaved roads management, geosynthetics in low-volume roads, drainage and stream crossings, climate change resiliency,...

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 531 documents agency practices, challenges, and successes in conducting automated pavement condition surveys. The report also includes three case examples that provide additional information on agency practices for conducting automated pavement surveys. Pavement condition data is a critical component for pavement management s...

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 533 identifies the current state of practice among state departments of transportation (DOTs) regarding selection and setup of very short duration work zone (VSDWZ). The report presents case examples of four state DOTs along with an in-depth analysis of the VSDWZ policies of these states. The case example agencies have develo...

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's Highway Innovations Deserving Exploratory Analysis (IDEA) Program Final Report 189: A Novel Vision Sensor for Remote Measurement of Bridge Displacement explores the development of a camera-based computer vision sensor system for remote measurement of multipoint bridge displacements in outdoor environments. The vision sensor tracks the movement of natural targets on the structure from a co...

TRB’s National Cooperative Highway Research Program (NCHRP) Research Report 912: Guidelines for Detection and Remediation of Soluble Salt Contamination Prior to Coating Steel Highway Structures consolidates practical guidance on the detection and remediation of soluble salt contamination prior to coating steel highway structures. Soluble salts are those that dissociate in solution into anionic ...