The Long-Term Pavement Performance Program

© J. D. Talasek/National Academy of Sciences

APPENDIX A. PLANNING AND ADVISORY COMMITTEES SUPPORTING THE LTPP PROGRAM

INTRODUCTION

Well before the LTPP program began in 1987 and continuing into the present, the input of stakeholders and the guidance of experts in the highway community have been critical to the success of the program. This appendix documents to the extent possible some of the committees and expert task groups (ETGs) that have planned the program, guided its implementation, and, through a Data Analysis Working Group (see page 264), helped to promote analysis of LTPP data.

Between 1987 and 1992, when the LTPP program was part of the Strategic Highway Research Program (SHRP), an independent agency of the National Research Council (NRC), LTPP management was guided by an arrangement among the Federal Highway Association (FHWA), American Association of State Highway and Transportation Officials (AASHTO), and the NRC. The NRC provided formal, external, peer review and advisory support for the LTPP program through an advisory committee assisted by specialized ETGs and subcommittees.^1,2 When SHRP ended, in 1992, NRC continued to provide these advisory functions through SHRP’s sister organization, the Transportation Research Board (TRB), and continues to do so.

Members of the planning and advisory committees and ETGs bring expertise in pavement engineering and performance monitoring, statistics and data analysis, information technology, and other specialized areas associated with the LTPP program’s goal and objectives. The members are drawn from highway agency staff, academia, pavement industries, consulting firms, and research institutions from across the United States and Canada. In addition, committee liaisons from AASHTO, C-SHRP (the Canadian SHRP), FHWA, international agencies, and other organizations provide important linkages. These liaisons are included in the membership lists.

The following sections list, to the extent they are available, the approximate dates the committees and ETGs served, their scopes, and the individuals who have participated during three periods (see sidebar):

• SHRP planning and pre-implementation advisors (circa 1982–86).
  
  
• Pavement Performance Advisory Committee (1987–95).
  
  
• TRB Long-Term Pavement Performance Committee (1996–present).

The service of some ETGs and many members has spanned these timeframes. Members of the advisory committees and ETGs during these periods are listed below (where known, chairpersons are shown in italics). Please note that these lists are incomplete and undoubtedly contain inaccuracies. Although an extensive search has been conducted, records were not always accessible. Some committees morphed into others, some had very short lifespans, and for some, documentation is no longer available. Any omissions of individuals who have contributed to the program, misattributions, or other errors are unintentional and deeply regretted.

SHRP PLANNING AND PRE-IMPLEMENTATION ADVISORS (1982–86)

The Strategic Transportation Research Study: Highways,³ was one of a series of studies that paved the way for implementation of the SHRP-LTPP program. The study was sponsored by FHWA and carried out by TRB. Additional research planning studies for SHRP were sponsored by the National Cooperative Highway Research Program and, in the case of the long-term pavement performance program, FHWA. These studies culminated in the publication in 1986 of Strategic Highway Research Program Research Plans: Final Report,⁴ in which the foundation for the LTPP program was laid. Following are the advisory groups that helped to shape the LTPP program through these pre-implementation studies.

Steering Committee for the Strategic Transportation Research Study: Highways

Strategic Highway Research Program Task Force

Strategic Highway Research Program Advisory Committee, Pavement Performance

PAVEMENT PERFORMANCE ADVISORY COMMITTEE (1987–95)

Scope

The major objective of the Pavement Performance Advisory Committee (PPAC), which reported to the SHRP Executive Committee,⁵ was to review the LTPP research plans for conformance with the established goal and objectives, for practicality and applicability to the technical needs of the operating highway agencies, and for engineering technological accuracy and feasibility. In addition, the committee was charged with identifying significant highway engineering products emerging from the LTPP studies and assisting the SHRP Executive Committee in developing priorities and recommendations for implementation.

The committee provided programmatic review and technical commentary on the program objectives, long-range plans, near-term operational activities, and progress of the LTPP research program; conducted external, nongovernmental reviews of research; and identified needs for further research projects. Planning and implementation of the LTPP program were emphasized, but other pavement performance research was also reviewed to identify gaps and overlaps, encourage cooperation, and foster the synthesis of further results. PPAC served from approximately 1987 to November 1995, a period that included the 5-year term of SHRP and the early years of the program under FHWA’s management.⁶ Following are the committee members and the ETGs that assisted the committee.

LTPP Benefits Subcommittee

Scope

This subcommittee was created by PPAC to review the outcomes that have resulted from the LTPP program and how these outcomes can benefit highway agencies in the design, construction, and maintenance and rehabilitation of their pavements.

Members

Allan L. Abbott
Larry Cole
Gary D. Taylor
Gary Sharpe
Carl Monismith
Ray Moore

Expert Task Group on Deflection Testing and Backcalculation

Scope

The ETG assisted in developing the SHRP backcalculation program by recommending criteria for the selection of software for use in the program, participating in the evaluation of six candidate backcalculation programs, and recommending Poisson’s ratio values for use in the backcalculation procedure.^7,8

Expert Task Group on Equipment Evaluation

Scope

The ETG provided guidance to SHRP staff on monitoring equipment used to collect pavement performance data for network- and project-level pavement management.

Expert Task Group on Experimental Design and Analysis

Scope

The ETG provided guidance to SHRP staff, consultants, and LTPP regional staff in the overall design of the experiments in the General Pavement Studies and Specific Pavement Studies by evaluating the analysis plans and recommending specific changes in the experiments. The ETG periodically reviewed the analysis procedures over the course of the studies, together with the SHRP Data Analysis Working Group, PPAC, SHRP staff, and technical contract staff.

Expert Task Group on LTPP Automated Distress Identification

Scope

The ETG provided assistance to SHRP in its effort to evaluate pavement distress on LTPP test sections and to suggest mechanisms for implementation at the State level. This ETG played a key role in the development of the SHRP Distress Identification Manual, which is one of the LTPP program’s most highly used products.

Expert Task Group on LTPP Traffic Data Collection and Analysis

Scope

The ETG provided guidance to SHRP staff, consultants, and LTPP regional staff for the traffic data collection program. The Traffic ETG played an active role in the program and was instrumental in several decisions regarding traffic and data collection requirements, site-specific data collection, database needs, weigh-in-motion requirements, guidelines in traffic variability and precisions, equivalent single-axle load calculations, traffic data analysis, and adoption of the FHWA vehicle classification system.^9,10

Expert Task Group on Weigh-in-Motion Equipment and Technology

Scope

The Weigh-in-Motion Equipment and Technology ETG was charged with determining the availability, uses, cost, and accuracy of equipment to fulfill the needs of the LTPP program to measure load on the pavement test sections.¹¹

Members

Lloyd Henion
Perry Kent
Billy M. McCall
Tom Neukam
John Van Berkel
Doug Warpoole
John Wyman

Expert Task Group on Environmental Data

Scope

The ETG assisted SHRP in the development of the climatic database, advising on the establishment of on-site weather stations to complement the “virtual” weather stations, the retention of both raw and composite climatic data obtained from the Canadian and U.S. weather services, data elements to be included, and the algorithm for deriving site-specific estimates from the climatic data.^12,13

Members

Richard L. Berge
Tom Christison
Walter Dabberdt
Barry J. Dempsey
John Griffith
David W. Phillips
Eugene Rasmusson

LONG-TERM PAVEMENT PERFORMANCE COMMITTEE (1996–present)

The FHWA contracted with TRB for provision of formal peer review regarding LTPP program matters. This contract has been renewed periodically and supports the continuation of the advisory committee, renamed the Long-Term Pavement Performance Committee (currently referred to as the LTPP Committee or LCOM), and its ETGs. The committee is appointed by, and acts through, the NRC.

Scope

The role of the TRB LTPP Committee is to advise FHWA and AASHTO on the planning, implementation, and development and delivery of products of the LTPP studies. The committee also prepares reports, including letter reports, containing its “evaluations and suggested mechanisms to enhance the utility to the States of the studies’outcomes.”¹⁴

Traditionally, individuals who are actively employed by highway agencies in the United States and Canada have occupied slightly more than half of the Committee’s membership seats, and one of these State appointees has served as chairperson. Participation in the development of the Committee’s advice to FHWA and AASHTO on the plans, operations, and accomplishments of the LTPP program affords the States and Provinces the opportunity to affect the future of this research program in which they are heavily invested.

Currently, the LTPP Committee is a TRB Policy Study Committee that meets regularly to receive reports from the LTPP program staff, deliberate, and develop recommendations regarding current and future activities related to the conduct and operation of the program. All members are required to comply with the conflict of interest and bias disclosure procedures of the NRC of the National Academies. Since 1997, the committee has submitted its findings to FHWA and AASHTO in the form of a formal review letter. The review letters are archived and available at the TRB Web site.¹⁵ At various times, the LTPP Committee has formed subcommittees to address specific issues, such as the Subcommittee on Program Improvement (March 1997 to March 1999). The committee also sponsors the LTPP State Coordinators’meetings and semi-annual meetings of the TRB Data Analysis Working Group.¹⁶

The TRB LTPP Committee has served since August 1996. In 2006, however, the size of the committee and the number of ETGs were trimmed back, reflecting a reduction in LTPP activities and TRB funding.¹⁷ The ETGs are described separately for the periods before and after 2006.

TRB LTPP Committee Expert Task Groups, 1996–2006

Expert Task Group on LTPP Automated Distress Identification / Distress Data Collection and Analysis

Scope

The ETG on LTPP Automated Distress Identification advised FHWA on planning and implementation of the collection and processing of 35-mm photographic records of pavement distress at LTPP test sections. The ETG provided advice intended to help solve operational problems with this activity; enhance the productivity of recording, identifying, and extracting the distress data; and assuring that the results addressed high-priority needs of State highway departments. Specific areas of activity included (1) programmatic review of the automated distress identification project’s objectives, priorities, and work plans; (2) technical assessment of ongoing work; (3) project-wide and task-specific progress assessment; and (4) recommendations to enhance project success.

The ETG’s members were selected for their expertise with equipment and methods used for automated recording of visual images of pavement surfaces and extraction from these records of distress data suitable for analysis of pavement performance, and for their experience in pavement engineering, statistics, and data analysis.

In 1999, at the ETG’s request, the LTPP Committee broadened the scope of this ETG and changed its name to the ETG on LTPP Distress Data Collection and Analysis. Although the ETG would continue to focus on automated identification of distress, its charge was widened to include “all aspects of collecting, processing, and uploading in the LTPP database data quantifying the type and extent of distress experienced by LTPP’s test sections.”¹⁸ The ETG served from July 1996 until November 2005.

Expert Task Group on LTPP Data Analysis

Scope

The ETG on LTPP Data Analysis was organized to advise FHWA on matters related to the development, through analysis of LTPP data, of research products that are needed and will be used immediately by State highway agencies. Specific areas of activity include (1) development and prioritization of data analysis objectives; (2) technical assessment of work plans for specific analysis projects; (3) technical review and advice regarding ongoing analytical efforts; (4) program-wide and project-specific progress assessment; (5) participation in periodic assessment and update of the LTPP Data Analysis Plan; (6) technical review of LTPP data analysis reports; and (7) referral of data analysis products to the LTPP Implementation Technical Working Group.¹⁹ Members were selected for their technical expertise in the analysis of pavement performance data and experience in pavement engineering, statistics, and data analysis.

Expert Task Group on LTPP Database Development and Operations

Scope

The ETG provided advice to the LTPP Committee and FHWA on (1) the further development of the LTPP database including the refinement of existing data tables and the addition of new data tables, including “computed parameters” tables and tables for data currently stored offline; (2) the further development of tools (such as the DataPave software, or Web-enabled versions of the database) for improving the accessibility of the LTPP data; (3) priorities, plans, and options for improving the accessibility of LTPP data not currently included in the LTPP database that may be of interest and value to users of the LTPP data; (4) plans for long-term maintenance and operation of the LTPP database; and (5) storage and dissemination of offline data following the sunset of the LTPP research program. Members were familiar with pavement performance data, data analysis, information technology, the fundamentals of relational databases, and the LTPP database.

The ETG’s purview included review of planning, implementation, and progress of LTPP database activities and advice regarding operational problems. Together with the TRB LTPP Committee, its other ETGs, and the Subcommittee on LTPP Product Development and Delivery, this ETG oversaw the planning and progress of LTPP projects to assure that their outcomes would lead to products addressing the high-priority pavement-related needs of State highway departments. The ETG served from October 2002 until November 2005.

Members

Roger L. Green
Leonnie Kavanagh
David P. Orr
Robert Raab
Shelley M. Stoffels
Deborah Walker
Eric Weaver
John R. Weaver
Benjamin Worel

Expert Task Group on LTPP Materials Data Collection and Analysis/Falling Weight Deflectometer Data Collection and Analysis

Scope

The ETG reviewed and advised the TRB LTPP Committee on matters relating to the collection, processing, and uploading materials properties data in the LTPP database. Established by the TRB LTPP Committee in 1999 because of the high level of materials data issues being brought to the attention of the Automated Distress Identification ETG, the new ETG addressed materials-related questions such as the robustness of techniques for backcalculation of resilient modulus from nondestructive testing, the repeatability of laboratory testing of resilient modulus, the precision and bias of resilient modulus testing, and the pros and cons of resilient modulus versus dynamic modulus. The scope of this ETG later expanded to include the review and analysis of falling weight delectometer data. Thus, the name changed to Expert Task Group on Materials and Falling Weight Deflectometer Data Collection and Analysis. The ETG served from December 1999 until October 2006.

Expert Task Group on Product Development and Delivery

Scope

The ETG provided technical advice to the TRB LTPP Committee on matters related to identification of LTPP products, the efforts to develop these products, and the plans to deliver these products to the State highway agencies. The ETG’s advice helped solve operational problems encountered in these activities, enhanced the productivity of the LTPP program, and assured that the program’s results address the high-priority needs of the States. Members included several members of the TRB LTPP Committee and other individuals who are well acquainted with the potential of the LTPP program to generate products of value to the highway community, including representatives of State transportation departments, transportation technology associations, consulting engineering firms, and universities. The ETG served from August 1999 to October 2003.

Expert Task Group on State Usage of the LTPP Data

Scope

The ETG on State Usage of the LTPP Data provided advice to the FHWA and AASHTO on the unique needs of State departments of transportation (DOT) regarding access to and use of data residing in the LTPP database. Activities of this committee included (1) evaluation of database users’service procedures, (2) evaluation of database user guides and other documentation, (3) evaluation of specific data delivery formats to afford ease of use, and (4) appraisal of the capacity of State DOTs to use LTPP data in DOT-staffed research and management activities.

Expert Task Group on Traffic Data Collection and Analysis

Scope

The ETG advised the TRB LTPP Committee, FHWA, and AASHTO on matters related to collection, processing, uploading in the LTPP database, and analysis of traffic data collected at LTPP test sites in the United States and Canada. The ETG provided comments and advice intended to help solve operational problems encountered in these activities. The work of the ETG was to facilitate the accumulation in the LTPP database of high-quality traffic data in quantities sufficient to support LTPP analysis projects. These projects are designed to produce outcomes that lead to products addressing the high-priority pavement-related needs of State/Province highway departments. The work of the ETG also included reviewing those parts of the plans, activities, and progress of the LTPP program’s data analysis and product development activities that pertain to the use of LTPP traffic data, and reporting its findings and suggestions to the TRB LTPP Committee. The ETG served from 1992 to 2013.

TRB LTPP Committee Expert Task Groups, 2006–2013

In 2006, as a result of budget constraints imposed on the LTPP program, the number of ETGs providing support to the TRB LTPP Committee was reduced to two: the TRB ETG on LTPP Traffic Data Collection and Analysis continued to provide the same functions as it had since 1992, and a multipurpose ETG on LTPP Special Activities was created to encompass many of the functions of the ETGs that were discontinued. Thus, between 2006 and 2013, the TRB LTPP Committee, with the support of the Traffic Data and Special Activities ETGs, provided the formal peer review functions for all LTPP-related activities. In 2013, the Traffic Data ETG was retired and its remaining responsibilities were folded into those of the Special Activities ETG.

Expert Task Group on LTPP Special Activities

Scope

The Special Activities ETG, referred to as LSPEC, advises the TRB LTPP Committee on matters related to collection, processing, uploading into the LTPP database, and analysis of all data, including traffic data as of 2013, that have been recorded at or determined from samples collected at LTPP test sites. The work of the ETG facilitates the accumulation in the LTPP database of high-quality data in quantities sufficient to support LTPP analysis projects. These projects were designed to produce outcomes addressing the high-priority, pavement-related needs of State highway agencies. The ETG’s scope of work includes reviewing the plans, activities, and progress of various aspects of the LTPP studies, including materials data collection and analysis, distress and profile data collection and analysis, data analysis, product development and delivery, and database development and operations.

Expert Task Group on LTPP Traffic Data Collection and Analysis (see 1996–2006 ETG section above; retired in 2013)

REFERENCES

1. “TRB Long-Term Pavement Performance (LTPP) Committee (B0135).” Web page. https://www.mytrb.org/CommitteeDetails.aspx?CMTID=4173.
   
   
2. “TRB Committees Related to Pavements Web page. http://www.trb.org/Pavements/TRBCommittees.aspx.
   
   
3. America’s Highways: Accelerating the Search for Innovation (Special Report 202). Transportation Research Board, National Research Council, Washington, DC, 1984.
   
   
4. Strategic Highway Program Research Plans, Final Report. Transportation Research Board, National Research Council, Washington, DC, May 1986.
   
   
5. Federal Highway Administration’s Commitment to the Strategic Highway Research Program: Past-Present-Future. January 1990. Available from LTPP Customer Support Service Center (ltppinfo@dot.gov).
   
   
6. Long-Term Pavement Performance Committee. Preserving and Maximizing the Utility of the Pavement Performance Database. Transportation Research Board, Washington, DC, 2009, p. vii. http://onlinepubs.trb.org/Onlinepubs/sp/ltpp_report_2009.pdf.
   
   
7. PCS/Law Engineering. Layer Moduli Backcalculation Procedure: Software Selection (SHRP-P-651). Strategic Highway Research Program, National Research Council. October 1993. http://onlinepubs.trb.org/onlinepubs/shrp/SHRP-P-651.pdf.
   
   
8. PCSLaw Engineering. SHRP’s Layer Moduli Backcalculation Procedure (SHRP-P-655). Strategic Highway Research Program, National Research Council, Washington, DC, August 1993, pp. 2, 18. http://onlinepubs.trb.org/onlinepubs/shrp/SHRP-P-655.pdf.
   
   
9. W. O. Hadley. SHRP LTPP Overview: Five-Year Report (SHRP-P-416). Strategic Highway Research Program, National Research Council, Washington, DC, June 1994, pp. 245–46. http://onlinepubs.trb.org/onlinepubs/shrp/SHRP-P-416.pdf.
   
   
10. J. L. German and C. R. Copeland, Jr. SHRP-LTPP Traffic Data Collection and Analysis: Five-Year Report (SHRP-P-386) (W. O. Hadley, Ed.). Strategic Highway Research Program, National Research Council, Washington, DC, March 1994, pp. 2–4. http://onlinepubs.trb.org/onlinepubs/shrp/SHRP-P-386.pdf.
    
    
11. J. L. German, C. R. Copeland, Jr., and W. O. Hadley (Eds.). SHRP LTPP Traffic Data Collection and Analysis: Five-Year Report (SHRP-P-386). Strategic Highway Research Program, National Research Council, Washington, DC, March 1994, pp. 2–5. http://onlinepubs.trb.org/onlinepubs/shrp/SHRP-P-386.pdf.
    
    
12. G. R. Rada. SHRP-LTPP Monitoring Data: Five-Year Report (SHRP-P-696). Strategic Highway Research Program, National Research Council, Washington, DC, August 1994, pp. 59–64. http://onlinepubs.trb.org/onlinepubs/shrp/SHRP-P-696.pdf.
    
    
13. PCS/LAW Engineering. Development of the LTPP Climatic Database (SHRP-P-621). Strategic Highway Research Program, National Research Council, Washington, DC, January 1993. http://onlinepubs.trb.org/onlinepubs/shrp/SHRP-P-621.pdf.
    
    
14. “TRB Long-Term Pavement Performance (LTPP) Committee (B0135).” Web page. https://www.mytrb.org/CommitteeDetails.aspx?CMTID=4173.
    
    
15. “TRB Policy Study Letter Reports and Other Brief Reports.” Web page. http://www.trb.org/publications/pubspolicystudiesletterreports.aspx.
    
    
16. Long-Term Pavement Performance Studies Web page. http://www.trb.org/LTPPProgram/LTPPProgram.aspx.
    
    
17. V. M. Mendez. Long-Term Pavement Performance Committee Letter Report (Letter No. 22). Dec. 18, 2006, p. 1. http://onlinepubs.trb.org/Onlinepubs/sp/ltpp_letter_22.pdf.
    
    
18. A. L. Abbott. Long-Term Pavement Performance Committee Letter Report (Letter No. 5) Apr. 1, 1999, p. 4. http://onlinepubs.trb.org/onlinepubs/sp/ltpp_letter_5.pdf.
    
    
19. C. J. Churilla. “FHWA’s Implementation Plan for SHRP Products.” Public Roads, Winter 1994. http://www.fhwa.dot.gov/publications/publicroads/94winter/p94wi24.cfm.