TRB Transportation Research Circular E-C172: Roadside Safety Design and Devices: International Workshop is a record of a meeting hosted by the International Research Subcommittee of the Roadside Safety Design Committee in Milan, Italy, on July 17, 2012. The focus of the meeting included assessment practices, safety systems, best practices, and other road safety products and issues.

TRB Transportation Research Circular E-C170: Nanotechnology in Concrete Materials: A Synopsis explores promising new research and innovations using nanotechnology that have the potential to result in improved mechanical properties, volume change properties, durability, and sustainability in concrete materials.

TRB’s Transportation Research Circular E-C169: Measuring the Transportation System from a Supply Chain Perspective provides a synopsis of the information from a July 2012 workshop that was designed to help to advance the understanding of if and how public-sector decision making could be improved by having better supply chain information. The circular also summarizes initial themes that were ide...

TRB Transportation Research Circular E-C168: Artificial Intelligence Applications to Critical Transportation Issues describes artificial intelligence (AI) applications in transportation and includes opinions on the future of AI by members of the committee that produced the report. The circular also contains 12 individually authored articles that describe five general AI areas: traffic operation...

TRB’s Transportation Research Circular E-C167: The Promise of Rural Roads reviews the role of low-volume roads in rural connectivity, poverty reduction, crisis management, and livability. The circular is based on the keynote address at the TRB 10th International Conference on Low-Volume Roads held in 2011 in Florida.

TRB Transportation Research Circular E-C166: Glossary for Regional Transportation Systems Management and Operations Terms: Second Edition is to avoid the frequently occurring misconceptions that arise through the use of different terms for the same meaning. E-C166 is an update of a previous edition published in April 2009 as Transportation Research Circular E-C133: Glossary of Regional Transpor...

TRB’s Transportation Research Circular E-C165: Alternative Binders for Sustainable Asphalt Pavement contains seven technical papers and summaries of presentations made at a January 22, 2012, workshop that explored material characterization and field validation for short- and long-term performance of various sustainable asphalt pavements.

TRB's Transportation Research Circular E-C164: Climate Change and Transportation: Summary of Key Information highlights the key findings of a variety of studies on the subject of climate change and its ramifications for the transportation sector conducted by the National Research Council, the principal operating agency of the National Academy of Sciences and the National Academy of Enginee...

TRB's Transportation Research Circular E-C163: Maintenance Management 2012 contains papers presented at the 2012 AASHTO–TRB Maintenance Management Conference held in Seattle, Washington, July 15–19, 2012. The objective of the conference--part of a series held every three to four years--was to provide a forum for the exchange of new ideas and developments in the maintenance and operations manage...

TRB’s Transportation Research Circular E-C162: Winter Maintenance and Surface Transportation Weather includes papers that were presented at the April 30-May 3, 2012, conference in Coralville, Iowa. Issues addressed by the papers include environmental stewardship and sustainability, road safety under winter conditions, decision support systems, winter surface friction, blowing and drifting snow,...

TRB’s Transportation Research Circular E-C161: Applications of Advanced Models to Understand Behavior and Performance of Asphalt Mixtures is a synopsis of information on the applications of advanced models to understand behavior and performance of asphalt mixtures.

TRB’s Transportation Research Circular E-C160: Polyphosphoric Acid Modification of Asphalt Binders: A Workshop documents the research discussed and presentations made at a April 2009 workshop that explored polyphosphoric acid-modified asphalt and its performance. The circular includes presentations made on a survey on polyphosphoric acid use and issues; the why and how of polyphosphoric acid mo...

TRB’s Transportation Research E-Circular E-C159: Teamwork in U.S. Railroad Operations: A Conference is a summary of the proceedings from an April 2009 conference that explored how modern teaming strategies might assist in improving the safety of railroad operations in the United States. The circular includes background papers, presentations, and summaries of breakout sessions held during the co...

TRB's Transportation Research E-Circular E-C158: Commodity Flow Survey Workshop is the proceedings of a November 2010 workshop that explored the next application of the Commodity Flow Survey (CFS). The CFS is a key data source for a myriad of freight planning activities.

TRB’s Transportation Research Circular E-C157: TRIS Turns 40: Results of a 2007 User Satisfaction Survey on the Transportation Research Information Service (TRIS) documents the results of an online survey of users of the TRIS database. The circular also includes background and information on the history and evolution of TRIS, information on several different versions of TRIS, and a discussion o...

TRB’s Transportation Research E-Circular E-C156: Automated Imaging Technologies for Pavement Distress Surveys documents state-of-the-art techniques and technologies in the acquisition of pavement surface images, and basic requirements needed to automatically identify and classify pavement surface distresses. The basics of film or magnetic tape–based image acquisition are presented in the circul...

TRB’s Transportation Research E-Circular E-C155: Sensitivity Analyses for Flexible Pavement Design with the Mechanistic–Empirical Pavement Design Guide contains the proceedings of a workshop that was held in conjunctions with the 2010 TRB 89th Annual Meeting. The workshop was developed to provide information for transportation agencies in the process of, or considering the implementation o...

TRB Transportation Research E-Circular E-C154: Development of Warranty Programs for Hot-Mix Asphalt is a synopsis of current information for the development of warranty programs for hot-mix asphalt pavements. The opinions expressed in this e-circular are those of the document's author and do not necessarily reflect the views of the Transportation Research Board, the National Academies.

TRB Transportation Research E-Circular E-C153: Dynamic Traffic Assignment: A Primer is designed to help explain the basic concepts and definitions of dynamic traffic assignment (DTA) models and addresses the application, selection, planning, and execution of a DTA model. The report also describes the general DTA modeling procedure and modeling issues that may concern a model user.

TRB Transportation Research E-Circular E-C152: Adapting Transportation to the Impacts of Climate Change: State of the Practice 2011 focuses on transportation adaptation practices that can be implemented to yield potential benefits now and in the longer term. The document highlights what climate change adaptation means for the transportation industry. E-C152 was produced under the auspices ...

TRB’s Transportation Research E-Circular E-C151: Modeling Operating Speed is a synthesis of existing operating speed models developed in different regions of the world. The models are grouped according to roadway type. Limitations and deficiencies in existing operating speed models and suggestions for future work are also identified. Practitioner perspectives on the potential use of speed predi...

TRB Transportation Research E-Circular E-C 150: Advancing Regional Transportation Operations: A National Workshop is a summary of the December 2008 workshop held in Washington, D.C. The purpose of the workshop was to advance the state of the practice in regional approaches to managing and operating the transportation system in a multiagency, multimodal, and cross-functional manner with the goal...

TRB Transportation Research Electronic Circular E-C149: 75 Years of the Fundamental Diagram for Traffic Flow Theory: Greenshields Symposium includes the papers that were presented at a July 2008 conference that explored traffic flow theory’s history, recent developments, technological impacts, current status, and potential research needs.

TRB Transportation Research E-Circular E-C148: Critical Issues in Aviation and the Environment explores the environmental media affected by aviation activities and processes that link aviation and the environment. The circular consists of nine individually authored sections representing the authors' expert opinions on these issues. E-C148 updates and expands upon previous circulars while mainta...

TRB’s Transportation Research Circular E-C147: Development in Asphalt Binder Specifications includes papers that explore test methods and specifications for high-temperature permanent deformation, fatigue cracking, and low-temperature cracking.

TRB Electronic Circular E-C146: Trucking 101: An Industry Primer is designed to provide a basic picture of the structure of the U.S. trucking industry for public officials, policy makers, engineers, administrators, planners, academic researchers, journalists, and anyone who needs to think about issues affecting, or affected by, trucking. The report emphasizes that many of the distinct parts of ...

TRB’s Transportation Research Circular E-C145: Joint International Light Rail Conference--Growth and Renewal includes 24 peer-reviewed research papers that were presented as part of the April 2009 Joint International Light Rail Conference. Collectively, the papers provide up-to-date information on planning, design, construction, maintenance, and operations involved in running a light rail ...

TRB’s Transportation Research Circular E-C144: Research Needs Statements for Climate Change and Transportation includes a series of specific research needs statements on climate change and transportation designed as a resource to be used by universities, students, research organizations, government agencies, and other interested parties as they contemplate and fund research in this area.

TRB Transportation Research Circular E-C143: Modal Primer on Greenhouse Gas and Energy Issues for the Transportation Industry is primer designed to provide transportation decision makers with an inclusive, educated, and objective overview of the current state of the transportation industry from a greenhouse gas and energy standpoint.

TRB’s Transportation Research Circular E-C142: Methodology for the Development and Inclusion of Crash Modification Factors in the First Edition of the Highway Safety Manual explores the literature review procedure and inclusion process related to development of Part D—Crash Modification Factors of the Highway Safety Manual (HSM), which is expected to be released later this year. The development...

TRB Transportation Research Circular E-C141: Colorado's Full-Scale Field Testing of Rockfall Attenuator Systems explores the durability and performance of several currently available mesh and cable net products that can be used to construct rockfall attenuator systems, for which no design guidelines exist.

TRB Transportation Research Circular E-C140: A Review of the Fundamentals of Asphalt Oxidation: Chemical, Physicochemical, Physical Property, and Durability Relationships explores the current physicochemical understanding of the chemistry, kinetics, and mechanisms of asphalt oxidation and its influence on asphalt durability.

TRB’s Transportation Research Circular E-C139: Use of Accelerated Pavement Testing to Evaluate Maintenance and Pavement Preservation Treatments explores experiences where accelerated pavement testing (APT) has been successfully used for the assessment of pavement preservation and maintenance strategies. The goal of the report is to motivate future APT research for evaluation of maintenance and ...

TRB’s Transportation Research Circular E-C138: Critical Issues in Aviation and the Environment 2009 explores the major environmental media affected by aviation activities and the key processes that link aviation and the environment, including climate change, alternative fuels, and sustainability. The circular focuses on the state of science, rather than on policy, and the authors of various por...

TRB’s Transportation Research Circular E-C137: Glossary of Highway Quality Assurance Terms contains terms of common usage and accepted practice for terminology used in the highway quality assurance field.  The report is designed as a reference document.

TRB Transportation Research Circular E-C136: Implementation Status for Geotechnical LRFD in State DOTs explores various states’ experiences in the practical implementation of Load and Resistance Factor Design (LRFD) in geotechnical and substructure design.

TRB’s Transportation Research Circular E-C135 Maintenance Management includes papers presented at the 12th American Association of State Highway and Transportation Officials–TRB Maintenance Management Conference held in Annapolis, Maryland, July 19-23, 2009. The objective of this series of conferences is to provide a forum every 3 to 4 years for the exchange of new ideas and developments in the...

TRB’s Transportation Research Circular E-C134: Influence of Roadway Surface Discontinuities on Safety is designed to help highway engineers evaluate roadway maintenance guidelines and priorities. The report addresses safety issues related to roadway roughness, holes, and bumps; the positive effects of road surface discontinuities; pavement edges; friction variations; water accumulations; surfac...

TRB’s Transportation Research Circular E-C133: Glossary of Regional Transportation Systems Management and Operations Terms is designed to provide clear definitions of terms as they are typically used in the context of regional transportation systems management and operations.

TRB’s Transportation Research Circular E-C132: Young Impaired Drivers provides overview of the information presented and discussions among the participants at a June 3-4, 2008, workshop that explored the risks posed by young impaired drivers and how these risks might be ameliorated.  Background papers prepared for the workshop are also included. The workshop included perspectives on the i...

Transportation Research Circular E-C131, Transportation Asset Management: Strategic Workshop for Department of Transportation Executives summarizes a workshop held in Washington, D.C., in December 2006 that explored advancements in asset management that have the potential to lead to growth in asset management applications in the United States.

TRB’s Transportation Research Circular E-C130: Geophysical Methods Commonly Employed for Geotechnical Site Characterization explores how geotechnical, geophysical tools are used to image or characterize the shallow subsurface of the Earth, typically to depths of less than several hundred feet.

TRB’s Transportation Research Circular E-C129: Use of Inclinometers for Geotechnical Instrumentation on Transportation Projects explores the state of the practice and representative applications on the use of inclinometer systems for measuring ground deformation and performance of geotechnical design elements on transportation projects. The report examines inclinometer components and installat...

TRB’s Transportation Research Circular E-C128 includes papers that were presented at the 10th International Conference on Bridge and Structure Management held on October 20-22, 2008, in Buffalo, New York.  The conference brought together practitioners, administrators, and researchers from around the world to exchange information on the development, implementation, and utilization of...

TRB Transportation Research Circular E-C127: Implementation of an Airport Pavement Management System explores the role and data requirements for an Airport Pavement Management System (APMS).  The report also examines the benefits, costs, and common challenges associated with the implementation of an APMS.

TRB Transportation Research Circular E-C126: Surface Transportation Weather and Snow Removal and Ice Control Technology includes papers that were presented at the 4th National Conference on Surface Transportation Weather (June 16–17, 2008), and the 7th International Symposium on Snow and Ice Control (June 17–19, 2008), which were both held in Indianapolis, Indiana.  The E-Circular include...

TRB’s Transportation Research Circular E-C125: Evolving Role of Statewide Transportation Planning in an Era of Regional Funding and Governance reports on a July 7-8, 2006 peer exchange in La Jolla, California that explored this topic.

TRB’s Transportation Research Circular E-C124: Practical Approaches to Hot-Mix Asphalt Mix Design and Production Quality Control Testing explores the state-of-the-practice for Superpave mix design and specification, including a summary of changes made to the Superpave mix design procedure as a result of National Cooperative Highway Research Program research findings, American Association...

TRB’s Transportation Research Circular E-C123, Traffic Safety and Alcohol Regulation: A Symposium provides an overview of the information presented at a June 5-6, 2006, symposium that examined the role of alcohol regulation in traffic safety.  The report explores discussions among symposium participants and includes the background papers prepared for the workshop.

Transportation Research Circular E-C122, Asphalt Emulsion Technology: Review of Asphalt Emulsion Residue Procedures, explores methods used worldwide for the recovery of asphalt emulsion residue and examines new avenues for research and practice on the issue.

Transportation Research Circular E-C121, Information Assets to Support Transportation Decision Making: Report of a Peer Exchange of State Transportation Organizations, summarizes discussions at an April 17-18, 2007, peer exchange of state department of transportation officials and other professionals that focused on data and information uses, management strategies, needs, and gaps in their org...

Transportation Research Circular E-C120, Traffic Monitoring Data: Successful Strategies in Collection and Analysis summarizes sessions that took place as part of a May 2007 workshop in Washington, D.C., designed as a forum to exchange knowledge about successful strategies in the collection and the analysis of traffic data.

TRB’s Transportation Research Circular E-C119: North American Freight Transportation Data Workshop summarizes sessions that took place as part of a May 2007 workshop in Washington, D.C., that allowed data users and providers to discuss freight transportation data from a North American perspective.  The workshop highlighted changes in government-supplied data sources and explored data user...

TRB’s Transportation Research Circular E-C118: Lessons Learned from the AASHO Road Test and Performance of the Interstate Highway Systemincludes six papers that reflect on the performance of Interstate Highway System pavements and lessons learned from the American Association of State Highway Officials (AASHO) road test from 1956 to 1961 in Ottawa, Illinois.

TRB’s Transportation Research Circular E-C117: The Domain of Truck and Bus Safety Research explores information and perspectives on truck and bus safety research.  The report is designed to help establish a knowledge base and help identify potential future activities.

TRB’s Transportation Research Circular E-C116, Geotechnical Challenges of the Interstate Highway System: The First 50 Years and a Look Ahead, explores what geotechnical engineers have learned since the construction of the Interstate System and what they see as future challenges for the discipline.  The circular is based on presentations made during a session at the 2006 TRB 85th Annual Me...

TRB’s Transportation Research Circular E-C115: Challenges of Data for Performance Measures: A Workshop is the proceedings of a July 8, 2006, workshop in San Diego, California.  The workshop explored ongoing issues and research directions in data management processes for performance measures.

TRB’s Transportation Research E-Circular 114: Research Opportunities in Radio Frequency Identification Transportation Applications summarizes a conference by the same title that was held October 17 to 18, 2006, in Washington, D.C.  This conference focused on current and future research on radio frequency identification (RFID) technologies in transportation applications, which includ...

TRB has released Transportation Research Circular E-C113, Artificial Intelligence in Transportation: Information for Application includes six articles that explore five general artificial intelligence (AI) areas including knowledge-based systems, neural networks, fuzzy sets, genetic algorithms, and agent-based models.  The circular is designed to serve as an informational resource for tra...

TRB’s Transportation Research Circular E-C112, Joint International Light Rail Conference: A World of Applications and Opportunities is the proceedings of the Joint International Light Rail (LRT) Conference that was held in St. Louis, Missouri, on April 9-11, 2006.  The conference focused on planning and urban integration, vehicle design and innovation, infrastructure use, security a...

TRB’s Transportation Research Circular E-C111, Integrating Roadway, Traffic, and Crash Data: A Peer Exchange is the proceedings of a November 1-2, 2006, meeting held in Washington, D.C.  The peer exchange was designed to bring both data and highway safety professionals together to share experiences and identify key issues relating to integrating roadway, traffic, and crash data sour...

TRB's Transportation Research Circular E-C110: Geometric Design Strategic Research documents efforts leading up to and resulting from the Strategic Geometric Design Research Needs Workshop held in Williamsburg, Virginia, in July 2004. The report also contains research problem statements for possible use as a long-range geometric design research program by organizations such as the American Ass...

TRB’s Transportation Research Circular E-C109: Transportation Information Assets and Impacts: An Assessment of Needs explores the relationship between data, as the raw material, and information as the processed, useful product supporting decisions.  The report also examines the value of information in specific real decisions and outlines an ongoing process designed to help ensure th...

TRB’s Transportation Research Circular E-C108: Geospatial Information Technologies for Asset Management is the proceedings of an October 30-31, 2005, peer exchange held in Kansas City, Missouri.  The peer exchange focused on moving spatial technology applications to the next level by managing change, data integration, and communication.  Participants at the exchange identified resear...

TRB’s Transportation Research Circular E-C107: Control of Cracking in Concrete: State of the Art explores causes of cracking, testing, and ways of minimizing strains and stresses that can cause cracking in transportation structures such as bridge structures, pavements, and footings.

TRB Transportation Research Circular E-C106: Environmental Geospatial Information for Transportation summarizes a May 3-4, 2006, peer exchange that took place in Washington, D.C.  The peer exchange highlighted several examples of successful collaboration, data sharing, and the effective use of environmental geospatial information systems data in transportation planning.  The report f...

TRB Transportation Research Circular E-C105: Factors Affecting Compaction of Asphalt Pavements includes invited papers that were presented at a January 2005 workshop that explored asphalt practitioners’ concerns related to specifying and achieving density during hot-mix asphalt (HMA) pavement construction.  Issues covered by the papers include optimizing HMA construction temperature...

TRB’s Transportation Research Circular E-C104, Fifty Years of Interstate Structures: Past, Present, and Future documents some of the key legislation, specifications development, and advances in research, design, and construction for bridges and other highway structures since the signing of the Federal-Aid Highway Act of 1956.

TRB’s Transportation Research Circular E-C103, Concrete: The Sustainable Infrastructure Material for the 21st Century examines some of the research innovations in the 20th century that led to advancements in concrete.  The circular also explores what the future may hold as a result of the continuing advancements in high-performance durable concrete.

TRB Transportation Research Circular E-C102: Asphalt Emulsion Technology includes four papers designed to serve as an overview of the chemistry, production, quality assurance testing, and application of bituminous emulsions.  The papers were produced following a technical session at the 2005 TRB 84th Annual Meeting on bituminous emulsions.

TRB’s Transportation Research Circular E-C101, Driver Education: The Path Ahead includes a series of papers that were presented at a workshop held on September 12–13, 2005, in Washington, D.C.   Issues covered by papers in the circular include novice drivers, content of driver education, instructional methods for young drivers, student competency measures, novice driver t...

TRB’s Transportation Research Circular E-C099, Statewide Transportation Planning: Making Connections includes the presentations, resource papers, and summaries of views expressed by conference speakers, panelists, and participants at a May 18–20, 2003, conference held in Duck Key, Florida.  The presentations, breakout sessions, and informal discussions held during the conferen...

TRB's Transportation Research Circular E-C098, Maintenance Management 2006: Presentations from the 11th AASHTO–TRB Maintenance Management Conference, contains papers presented at the 11th AASHTO–TRB Maintenance Management Conference held in Charleston, South Carolina, July 16-20, 2006. The report includes papers on outsourcing, pavements, roadside, winter operations, bridges, maint...

TRB’s Transportation Research Circular E-C097, International Perspectives on Urban Street Design: Proceedings of the Context-Sensitive Design Workshop includes four papers that were presented during the 2005 TRB 84th Annual Meeting.  The papers explore street design in small European towns; context-sensitive design aspects of arterial streets in Berlin, Germany; and issues relative ...

TRB’s Transportation Research Circular E-C096, Drugs and Traffic: A Symposium provides an overview of the information presented and the discussions among the participants, as well as the background papers prepared for a June 20-21, 2005, symposium held in Woods Hole, Massachusetts.  The goal of the symposium was to synthesize and summarize available information on the role of drugs ...

TRB’s Transportation Research Circular E-C095, Operations Data for Planning Applications: Identifying Needs, Opportunities, and Best Practices summarizes a May 4, 2005, Washington, DC, peer exchange that focused on opportunities to improve the linkages between transportation planning and operations.  The report includes a summary of questions addressed by participants about the rela...

TRB’s Transportation Research Circular E-C094, Safety Data Analysis and Evaluation: Research Problem Statements contains research problem statements produced by members and friends of TRB’s Safety Data, Research, and Analysis Committee (ANB20).  The committee is concerned with methods of gathering, storing, and, in particular, using the transportation safety data for informed ...

TRB’s Transportation Research Circular E-C093: 6th National Conference on Transportation Asset Management summarizes the content of the sessions and presentations from the November 1–3, 2005, conference in Kansas City, Missouri.  The circular includes a summary of each conference session as well as summaries of the individual topics included in the session.  The circular ...

TRB’s Transportation Research Circular E-C092, Maintenance and Operations of Transportation Facilities: 2005 Strategic Vision explores the major trends that affect maintenance; cites current and emerging innovations in management systems, technology, and intelligent transportation systems; and examines some of the key maintenance challenges of this century.

TRB Transportation Research Circular E-C091, Innovations in Statewide Planning: A Peer Exchange summarizes a July 2005 peer exchange on innovations in statewide planning.

TRB Transportation Research Circular E-C090, Design–Build: A Quality Process summarizes an all-day workshop that took place at the 2005 TRB 84th Annual Meeting.  The workshop focused on achieving quality on design-build projects from the preparation of the request for proposals, to the actual design, to the use of incentives to achieve desired levels of quality, and to final construction.

TRB’s Transportation Research Circular E-C089: Critical Issues in Aviation and the Environment 2005 updates a 2004 summary of critical issues in aviation and the environment.  The 2005 report identifies priority research that may yield potential benefits to environmental media affected by aviation activities (noise, air quality, and water quality) and processes that link aviation and the ...

TRB Conference Proceedings E-C088: Commodity Flow Survey Conference is the proceeding from a conference held in on July 8-9, 2005, in Boston, Massachusetts.  The conference examined the commodity flow survey (CFS), reviewed data sources being used to supplement information from the CFS, and explored ideas to improve future iterations of the CFS.

TRB Electronic Circular E-C087: Rubblization of Portland Cement Concrete Pavements includes non-peer reviewed papers that were written based on presentations made during sessions on rubblization of portland cement concrete pavements at the TRB 84 Annual Meeting in January 2005.  Hot-mix asphalt (HMA) overlays can also be considered for application to an existing, deteriorated portland cem...

TRB Electronic Circular E-C086: Evaluation of Chemical Stabilizers: State-of-the-Practice Report is designed to provide information on practices that agencies have found to be successful and tp provide a reasonable degree of uniformity and standardization in the evaluation of chemical stabilizers used in soil stabilization. The circular is intended to provide the potential users of any chemica...

TRB Transportation Research Circular E-C085, Railroad Operational Safety: Status and Research Needs summarizes the proceedings of the Midyear Meeting of the Transportation Research Board’s (TRB) Railroad Operational Safety Subcommittee held September 10–12, 2002, in Irvine, California, which examined human factors-related research issues facing the railroad enterprise. The report includes rese...

TRB Research Circular E-C084 presents the top 16 pedestrian research problem statements, prioritized from a list of approximately 80 research problem statements by TRB’s Technical Activities Division Committee on Pedestrians.  

TRB Transportation Research Circular E-C083: National Roundabout Conference: 2005 Proceedings includes presentations made during the May 22-25, 2005, conference in Vail, Colorado.  Issues examined during the conference included the range of settings where roundabouts may be used, design elements and criteria, and methods of estimating safety and operations impacts.  The conference al...

TRB Transportation Research Circular E-C082, Statewide Multimodal Transportation Planning Proceedings: 2004 Peer Exchange focuses on cost estimating for transportation planning and incorporating safety into the transportation planning process.  The report provides an overview of the presentation and roundtable discussions that took place during the peer exchange on July 27-28, 2004, in Pa...

TRB Research Circular E-C081: A Research Program for Improvement of the Highway Capacity Manual describes a research program designed to improve the Highway Capacity Manual (HCM). The proposed program was developed by the members of the TRB Highway Capacity and Quality of Service Committee with the assistance of feedback from users of the HCM.  The program includes 38 research studies tha...

TRB Electronic Circular E-C080: Freight Data for State Transportation Agencies documents a peer exchange that was held July 11, 2005, in Boston, Massachusetts.  At the peer exchange, participants identified major challenges and issues relating to freight data. Some of those challenges and issues include the determination of data and information needs, logistics and supply chain analysis, ...

TRB Electronic Circular E-C079: Calibration to Determine Load and Resistance Factors for Geotechnical and Structural Design explores how load and resistance factors are developed.  The circular includes information on how to estimate load and resistance factors where adjustment of these factors is justified based on local experience and data.  The circular also includes criteria for ...

TRB Electronic Circular E-C078 Roadway Pavement Preservation 2005 contains papers written for the TRB First National Conference on Roadway Preservation held in Kansas City, Missouri, on October 31-November 1, 2005.  The conference addressed all aspects of successfully implemented roadway pavement preservation activities, including management, engineering, economics, the establishment of s...

TRB’s Electronic Circular 77--Enhancing the Value of Data Programs: A Peer Exchange contains the proceedings of a peer exchange that took place on July 23-24, 2001, in Vail, Colorado.  The purpose of the exchange was to share ideas on raising the awareness of data programs and ensuring that data add value to the operation of state departments of transportation.  The forum examined wh...

TRB Electronic Circular E-C076: Asset Management in Planning and Operations--A Peer Exchange summarizes a September 7–8, 2004, peer exchange that focused on the expanding role of asset management in planning and operations as a comprehensive approach to managing agency resources and transportation systems.  The peer exchange was designed to gather additional information about the state of...

TRB Electronic Circular E-C075: Statewide Travel Demand Modeling—A Peer Exchange includes presentations made during the September 23–24, 2004, peer exchange and includes comparison of travel demand modeling efforts taking place in select states.

TRB Electronic Circular E-C074: Glossary of Highway Quality Assurance Terms—Third Update contains terms of common usage and accepted practice in the area of highway quality assurance (QA). The report is designed as a reference document that contains common usage of highway QA terminology.

TRB Transportation Research Circular E-C073: Performance Measures to Improve Transportation Planning Practice: A Peer Exchange summarizes the results of a peer review on the use of performance measures to improve transportation planning and its relationship to project programming.  The one-day peer review focused on how state departments of transportation are using performance measures to...

TRB’s Electronic Circular 72: Implementing Impaired Driving Countermeasures: Putting Research into Action—A Symposium summarizes a symposium that was held on August 21-22, 2003, in Irvine, California. The circular provides an overview of the information presented and discussions among the participants, as well as the background papers prepared for the symposium.

TRB’s Electronic Circular 71: Data for Understanding Our Nation’s Travel: National Household Travel Survey Conference summarizes a conference held on November 1-2, 2004, in Washington, D.C. The conference was designed to bring together a diverse set of data users who understand the data’s usefulness in order to provide feedback to inform the design of future national travel behavior surveys.&n...

TRB's E-Circular 70 - Optimizing the Dissemination and Implementation of Research Results: A Summary of Workshop and Midyear Meeting Activities examines the issues and challenges associated with optimizing the dissemination and implementation of research results. This TRB E-Circular also documents the problem exploration process and the potential priority actions from these efforts.

TRB’s Electronic Circular E-C069: Critical Issues in Aviation and the Environment identifies priority research focused on existing and future environmental impacts of aviation on the environment and the opportunities for mitigating or avoiding those impacts.  This is first in what is planned to be an annual summary of critical issues in aviation and the environment to be developed by TRB’...

TRB Circular E-C068: New Simple Performance Test for Asphalt Mixes includes a series of papers that examine practical and reliable laboratory tests that could be considered for ranking the rutting potential of hot-mix asphalt paving mixtures.  The circular also includes a literature review on performance tests.  

TRB’s Transportation Research Circular E-C067: Context-Sensitive Design Around the Country: Some Examples describes Context-Sensitive Design (CSD) projects presented during the 2003 TRB 82nd Annual Meeting.  CSD is defined as a project development process, including geometric design, that attempts to address safety and efficiency while being responsive to or consistent with the road’s nat...

TRB Transportation Research E-Circular 66 is the proceedings of the National Metropolitan Planning Organization Peer Exchange that took place on May 20-21, 2003, in Duck Key, Florida.  The proceedings include information on near-term planning research topics and needs, short-term needs for transportation planning capacity building, and long-term research topics for the TRB Committee on Me...

TRB’s Electronic Circular E-C065: Transportation Security Education and Training summarizes the transportation security education and training presentations at the TRB’s 83rd Annual Meeting, January 11–15, 2004, and emphasizes the important security duties transportation professional’ play in protecting against and reacting to security events.

TRB’s Transportation Research Circular E-C064 -- Data Requirements in Transportation Reauthorization Legislation: What Is Included and Impacts on the Data Community highlights a TRB conference held on November, 19, 2003, in Washington, DC, that examined data issues associated with the programmatic proposals being considered for surface transportation reauthorization legislation, including new a...

TRB Electronic Circular 63: Sixth International Symposium on Snow Removal and Ice Control Technology is the compendium of papers for the June 7-9, 2004, Spokane, Washington symposium.  Issues addressed at the symposium included winter weather (information, models, and data quality); winter maintenance (policy, management, and performance); customers’ perspectives on winter operations; env...

TRB Transportation Research Circular E-C062: Addressing Fiscal Constraint and Congestion Issues in State Transportation Planning is the proceedings from a peer exchange held on July 14–16, 2002, in Wood’s Hole, Massachusetts.

TRB Transportation Research Circular E-C061: Data Partnerships: Making Connections for Effective Transportation Planning is the proceedings of a peer exchange held on May 21, 2003, in Duck Key, Florida. The meeting addressed some of the benefits and challenges facing the development of transportation data partnerships.

TRB Transportation Research Circular EC060: Using Simulation to Evaluate Impacts of Airport Security -- 2003 Simulation Workshop documents the proceedings of a January 12, 2003, workshop. The primary objective of this workshop was to present, demonstrate, and discuss the passenger and baggage screening simulation techniques used to comply with the Transportation Security Administration’s (TSA) ...

TRB Transportation Research Circular E-C059: Accelerated Highway Construction, Workshop Series Summary summarizes three workshops held in Washington, D.C., Indianapolis, Indiana, and Pittsburgh, Pennsylvania, in 2000-2002. The objective of this workshop series was to provide a forum for the exchange of new ideas and developments in the field of accelerated construction.

TRB Transportation Research Circular E-C058 includes the proceedings of the 9th National Light Rail Transit Conference held November 16-18, 2003, in Portland, Oregon. The ninth national conference focuses on the planning, design, construction, operation, maintenance, and administration of LRT systems.   TABLE OF CONTENTS FRONT MATTER Cover 2003 LRT Conference Planning Committee Forward Co...

TRB Transportation Research Circular EC057 - The Roadway INFOstructure: What? Why? How? summarizes an August 21-23, 2002, workshop in Irvine, California, which examined the Federal Highway Administration’s vision for a Roadway INFOstructure. The Roadway INFOstructure was designed as the road and highway component of the Integrated Network of Transportation Information.

TRB Transportation Research Circular E-C056: The Future of MEMS: Microelectromechanical Systems in Transportation Engineering introduces microelectromechanical systems (MEMS) into transportation engineering by describing the general concept and the issues related to their development. MEMS are a relatively new innovation in the integrated circuit field. Although there are a few developed applic...

TRB Transportation Research Circular E-C055: A National Forum on Assessing Historic Significance for Transportation Programs presents the proceedings of a forum held in Washington, D.C., on May 23–25, 1999.

TRB Transportation Research Circular E-C054: Third National Community Impact Assessment Conference includes the proceedings of the conference, which was held in Madison, Wisconsin, on August 19-21, 2002. Community Impact Assessment is an iterative process of understanding potential impacts of proposed transportation activities on affected communities and their sub-populations throughout transpo...

TRB Transportation Research Circular EC053: 9th International Bridge Management Conference Supplement includes two papers that cover Dynamic Load Tests in Bridge Management and Hybrid Knowledge Representation in Bridge Management Systems. This circular is a supplement to Circular E-C049 (http://trb.org/publications/circulars/ec049.pdf) . Papers in both Circulars were presented at the 9th Intern...

TRB Transportation Research Circular EC052: Maintenance Management 2003 contains papers presented at the Tenth AASHTO-TRB Maintenance Management Conference held in Duluth, Minnesota, July 13-17, 2003. The objective of this series of conferences is to provide a forum every three to four years for the exchange of new ideas and developments in the maintenance and operations management of transport...

TRB Transportation Research Circular E-C051: Future Aviation Activities - 12th International workshop summarizes a September 18-20, 2002 Transportation Research Board and Federal Aviation Administration workshop on forecasting long-term trends and developments in commercial, business, and personal air transport.

TRB Transportation Research Circular EC050: Transportation and Economic Development 2002 summarizes presentations from a May 5-7, 2002, conference that offered transportation, economic development, and planning professionals a broader understanding of the most timely and important issues linking transportation and economic development.

TRB Transportation Research Circular E-C049 contains papers on bridge management concepts, strategies and health indices, asset management, joints, coatings and concrete repair, life - cycle costs, load testing, utilizing the Internet and performance measures, deterioration and reliability, future directions and challenges in bridge management systems, management system implementation, safety a...

TRB Transportation Research Circular E-C048: Freight Transportation Research Needs Statements identifies critical issues in freight transportation as a resource for researchers in the freight area and serves as a seedbed for further discussion and analysis from a wider cross-section of freight practitioners.

TRB Transportation Research Circular E-C047: Financial Aspects of Equipment Information includes assistance on analyzing various financial acquisition choices and their impacts on budget, total costs, and fleet upgrade factors.

TRB Transportation Research Circular E-C046: Using Spatial Data, Tools, and Technologies to Improve Program Delivery chronicles a peer exchange that focused on optimum use of spatial data, tools, and information to facilitate decision making and to deliver multimodal transportation programs.

TRB Transportation Research Circular E-C045: 2002 California HOV Summit Proceedings The proceedings from TRB's May 3, 2002, California HOV Summit, which examined the latest events and research findings surrounding high-occupancy vehicle lanes, are now available in .

TRB Transportation Research Circular Number E-C044: Bailey Method for Gradation Selection in Hot-Mix Asphalt Mixture Design includes a synopsis of current information on a systematic approach to selecting and adjusting aggregate gradation in hot-mix asphalt design.

TRB Transportation Research Circular E-C043: Significance of Restricted Zone in Superpave Aggregate Gradation Specification presents the historical basis of the restricted zone in hot-mix asphalt (HMA) mixes and summarizes the published research conducted on the restricted zone to determine its significance within the Superpave gradation specification. A characteristic hump in a mix gradation w...

TRB Transportation Research E-Circular Number E-C042: Airport - Airspace Simulations: A New Outlook documents proceedings from a workshop produced by TRB's Committee on Airspace and Airfield Capacity and Delay.

TRB Transportation Research E-Circular 41: Supporting the Establishment of Safety Transportation Networks includes an introduction to safety-conscious planning and a toolkit to organize and conduct a safety-conscious planning forum.

TRB Transportation Research E-Circular E-C040: Aviation Demand Forecasting -- A Survey of Methodologies includes examples of the diversity of techniques used in forecasting aviation system demand and market analyses.

TRB Transportation Research Circular E-C039: Conference on Transportation Improvements: Experiences Among Tribal, Local, State, and Federal Governments is the proceedings from a conference held on October 18–21, 2001 in Albuquerque, New Mexico that focused on the complexity of broad transportation issues of importance for Native American nations.

TRB Transportation Research Circular E-C038: Standards for Testing, Evaluating, and Locating Roadside Safety Features includes presentations by international experts on standards for testing, evaluating, and locating roadside safety features--from a meeting of the TRB Committee on Roadside Safety Features (A2A04) Subcommittee on International Research Activities (A2A04(2)).

TRB Transportation Research Circular E-C037: Glossary of Highway Quality Assurance Terms includes standards for usage of highway quality assurance terminology.