Long Term Pavement Performance

Prepared by

Task Committee on the LTPP Contest
The Transportation and Development Institute of ASCE

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Table of Contents

1. Introduction

1.1 Background
1.2 Scope

2. Long Term Pavement Performance (LTPP) Program

2.1 Background
2.2 DataPave Tool

3. Categories and Awards

3.1 Categories

4. Participants

4.1 Student Participants
4.2 Faculty Participants
4.3 Other Participants

5. Guidelines for Participation

5.1 Timeline for Contest
5.2 Guidelines for Paper Preparation
5.3 Evaluation Process
5.4 Review Process
5.5 Publication of Papers
5.6 Paper Submission

1. INTRODUCTION

1.1 Background

The “International Contest on LTPP Data Analysis” is a joint effort between the Federal Highway Administration (FHWA), the Long-Term Pavement Performance (LTPP) Program, and the Task Committee on Long-Term Pavement Performance Contest, a subcommittee of the Highway Pavement Committee of the Transportation and Development Institute (T&DI) of the American Society of Civil Engineers (ASCE).  The contest was initiated in August 1998 and is designed to encourage students, professors, State Highway Officials, and consultants from around the world to get involved in using the LTPP data compiled by the FHWA over the past 17 years.  The database offers a unique opportunity for everyone to work individually or in teams, in the development of papers, which will benefit transportation engineers and which will be considered for awards.  All participants receive letters of recognition.  Winners receive cash prizes, plaques, and certificates as per the recognition awards described in this guide.  FHWA will reserve the right to publish the winning papers in an LTPP research document, which will be available for free to anyone who desires a copy.

1.2 Scope

This guide provides the information that contestants will need in order to participate in the international contest.  It includes the following:

1. Background of the LTPP program.
2. An introduction to the DataPave online web tool that contains the most recent LTPP data;
3. Critical dates for the contest - paper submission, review period, and recognition;
4. Guidelines for paper submission and evaluation criteria;
5. Contest Awards and recognition for the contest winners;
6. Expected benefits of the contest.

2. LONG TERM PAVEMENT PERFORMANCE (LTPP) PROGRAM

2.1 Background

During the early 1980s in the United States of America, the Transportation Research Board (TRB) of the National Research Council, under the sponsorship of the Federal Highway Administration (FHWA) and with the cooperation of the American Association of State Highway and Transportation Officials (AASHTO) undertook a thorough study of the deterioration of the nation’s highway and bridge infrastructure system.  The study recommended that a “Strategic Highway Research Program (SHRP)” be initiated to focus research and development activities that would make major contributions to improving highway transportation.  The study report, published as TRB Special Report 202 during 1984, emphasized six research areas, with the Long Term Pavement Performance (LTPP) program as one of the key research areas.  During 1985 and 1986, independent contractors developed details of the research programs for SHRP.  The detailed programs were published in May 1986 as a TRB Report entitled “Strategic Highway Research Program - Research Plans.”

The SHRP program, now finished, was passed on to the FHWA in 1992 and is currently called the Long-Term Pavement Performance (LTPP) program. It continues the work started by its predecessor, the SHRP program until it is concluded.  The LTPP program continues the research study of in-service pavements as it was envisioned by SHRP, as a comprehensive program to satisfy a total range of pavement information needs.  It draws on technical knowledge of pavements presently available and seeks to develop better models to explain how pavements perform.  It also seeks to gain knowledge of the specific effects on pavement performance due to various design variables, such as traffic, environment, materials, construction quality, and maintenance practices.  As sufficient data becomes available with time, analysis is conducted to provide better performance prediction models for use in design and pavement management.

The overall objective of the LTPP program is to increase pavement life by investigation of various designs and rehabilitated pavement structures, using different materials and under different loads, environments, sub-grade soil, and maintenance practices.  The specific objectives for the LTPP program are:

1. Evaluate existing design methods.
2. Develop improved design methodologies and strategies for the rehabilitation of existing pavements.
3. Develop improved design equations for new and reconstructed pavements.
4. Determine the effects of (a) loading, (b) environment, (c) material properties and variability, (d) construction quality, and (e) maintenance levels on pavement distress and performance.
5. Determine the effects of specific design features on pavement performance.
6. Establish a national long-term pavement database to support the programs objectives and future needs.

The LTPP program comprises a matrix of several types of studies.  These include General Pavement Studies (GPS) and Specific Pavement Studies (SPS).  The GPS involve a very large experiment consisting of in‑service pavement test sections throughout the U.S. and Canada embracing an array of site selection factors that provide information for a national database to meet the objectives of the LTPP program.  The SPS have their own set of limited goals, construction needs, and experimental approaches that cannot be achieved by the GPS.  The SPS are intensive studies of few specific variables.  In addition to the GPS and SPS test sections, a separate program was established to study the effects of environment on the long-term performance of in-service pavements, the Seasonal Monitoring Program (SMP).  About 65 GPS sections were designated as SMP test sections.  For the SMP sites, continuous or more frequent data collection is performed to capture the effect of environmental variation on pavement performance.

Several broad classes of data are contained in the LTPP database including:

1. General information
2. Inventory data
3. Climatic data
4. Materials test data
5. Maintenance data
6. Rehabilitation data
7. Traffic data
8. Pavement monitoring data

The LTPP data being collected are housed in an Information Management System (IMS).  It is the world’s largest pavement performance database ever created, with enormous potential for the development of products to improve pavement technologies in the future.    The document “Introduction to LTPP Data” (April 1999) presents a discussion of the uses of and limitations of LTPP data in pavement performance analyses, general data availability, and data update schedule. 

For further details on the LTPP program, please visit on the INTERNET: https://www.fhwa.dot.gov/pavement/ltpp/ or contact Antonio Nieves Torres (FHWA) at 202-366-4597 email: Antonio.Nieves@fhwa.dot.gov, Andrea Baker at (ASCE/T&DI) 703-295-6124 email: abaker@asce.org.

2.2 DataPave Tool

Because of the size of the LTPP database, which is evolving continuously to accommodate data collected over a period of 17 years, the IMS is designed to optimize storage space.  The data are stored using a relational database design that involves over 6,000 data elements in over 400 tables.  This approach greatly enhances the system’s ability to store massive amounts of data in a very organized fashion.  However, the storage scheme makes data accessibility somewhat difficult, since it requires extensive knowledge of the information and format of the LTPP database, which includes knowledge about the database structure, data codes, data collection, testing protocols, and relationships between data tables.  To address the need for a structured and user-friendly LTPP data source accessible from a desktop computer, a tool was created called “DataPave”.  DataPave was first created in software form and now provided online at www.LTPP-Products.com.   The primary objective of this tool is to provide the LTPP database users with a user-friendly front-end application that can be used to explore, extract, and organize the LTPP data along with having the most recent data release of the LTPP database available to users. 

The first step in using DataPave is to select the LTPP test sections of interest to the user.  There are several ways of accomplishing this. Two most popular ways are either by using the Visualization by location or Criteria method.

• Visualization method (By Location) using online map

  Steps:

  1. Enter the DataPave website.
  2. Select the Visualize, then by location.
  3. From the drop down menu on the right side of the windows select the appropriate experiment type GPS, SPS, or SMP.
  4. Click refresh map.
  5. Select Zoom in button.
  6. Select an area of the state you desire by clicking on the upper left-hand side of the state and dragging the cursor to select the state.  This is will zoom into the state you want.
  7. Select the specific experiment GPS-1, SPS-5 or SMP experiment from the toggle list on the right-hand side of the window and click the refresh map button at the bottom of the page.
  8. Zoom in as desired (optional)
  9. Then click on the “Identify” button to select the site-specific experiment you wish to view.
  10.  The screen will change to the “Detail Report” page which will give up a birds-eye view of selected data for that site.
  11. Select the site section number you wish to download data from and click “Export”.
  12. The screen will refresh to the “Data Extraction” window.
  13. Select the IMS module and table you wish and the fields that you wish.
  14. Select the sections you want (limited to 20 sites)
  15. Select the file format
  16. Click export

PROS:  Quick easy way to access some site data.

CONS: Search is limited to table specific data only.  Only 20 sites can be selected at any particular time.

NOTE 1:  This selection will provide performance data for the selected LTPP section(s).

• By Criteria

  Steps:

  1. Select first the state(s), or LTPP region.
  2. Select Experiment type (i.e. GPS, SPS, SMP).
  3. Select Parameters such as climatic region, subgrade type, and other filter criteria.
  4. Select the site section number you wish to download data from and click “Export”.
  5. The screen will refresh to the “Data Extraction” window.
  6. Select the IMS module and table you wish and the fields that you wish.
  7. Select the sections you want (limited to 20 sites)
  8. Select the file format
  9. Click export.

NOTE 2:  This selection will provide performance data for the selected LTPP section(s). When using either method performance trends and detailed information can be obtained.

PROS:  Quick easy way to access some site data.

CONS: Search is limited to table specific data only.  Only 20 sites can be selected at any particular time.

NOTE 3:  A summary of the requested information is displayed in the following screen.  Three additional documents can be downloaded at this time as well.

• LTPP Data Disclaimer
• LTPP Data Dictionary
• LTPP Data Codes

IMPORTANT NOTE: If you are planning to export all the information available from any particular table for all the LTPP test sections, the only way to do this is by using the “SQL Export” feature.  You must build the SQL query in order for the web site to handle the amount of data that might potentially be downloaded.  Kept in mind that the site has a size limitation of 10 mb, and that multiple downloads might be needed to retrieve all the data needed for a particular analysis. The Table Export and SQL Export options are the two means that provide greater flexibility for download of data.

3. CATEGORIES and AWARDS

3.1 CATEGORIES

Table 3.1 below describes the four categories and the awards.

Table 3.1 Categories, Team Composition, and Awards

4. Participants

4.1 Student Participants

Graduate and Undergraduate students who graduate anytime during the academic year are eligible to participate.  Students who are full-time employees on LTPP-related contracts are NOT eligible to participate in the contest.  Students that wish to participate in the contest must be sponsored by at least one faculty advisor.  The participants must submit a letter of sponsorship from the faculty advisor showing his (her) support and that the paper was neither published nor submitted for publication elsewhere.

4.2 Faculty Participants

Faculty advisors are NOT permitted to be co-authors with students in the undergraduate or the graduate categories, but their names can be listed as “Faculty Advisors” on the submitted paper manuscript.  The cash prize, however, goes to the student team.  Faculty members, however, can participate as authors in the curriculum category.

4.3 Other Participants

Non-student or faculty may participate with students under the partnership category. This may include:

1. Highway and Other Agencies

• Pavement designers
• Materials engineers
• Maintenance engineers
• Traffic forecasters
• Pavement management engineers

2. Researchers

• Consultants and research facilities
• Agency research groups

3. Industry

• Paving associations (e.g., NAPA, ACPA, AAPT)
• Manufacturers of paving materials (e.g., TAI, NSA)
• Automobile and truck associations (e.g., AAA, ATA)
• Consultants

4. International Organizations

• International Road Federation (IRF)
• PIARC
• World Bank
• US AID
• Pan-American Institute of Highways (PIH) (Non-University centers, university centers must participate under graduate and under graduate categories)

5. GUIDELINES FOR PARTICIPATION

5.1 Timeline for Contest

Following is the timeline for the International Contest:

5.2 Guidelines for Paper Preparation

The paper preparation guidelines are provided in Appendix A.  They can also be viewed at the www.LTPP-Products.com web site. Each paper must have a cover page including all authors’ names, affiliation and addresses. The cover page must also list the category under which the paper is submitted.  An example of the cover page format is shown in Appendix B, and can also be downloaded from the LTPP contest web site. 

Length of Manuscripts

The length of each paper, including the abstract and references may not exceed 7,500 words; that is, a paper that is only text should contain no more than 7,500 words.  Each figure, photograph, or table accompanying the text counts as 250 words.  For example, if two figures and three tables are submitted, the text may be no more than 6,250 words.

Note that 7,500 words is the maximum length; authors are encouraged to keep papers to the minimum length possible, and limit the number of figures and tables, providing only essential information of interest to the reader.

The total number of words in the paper should be noted on the title page. Overlong papers will NOT be considered by the Contest Board.

Length and Content of Abstracts

Each paper must have an abstract. The abstract must be no longer than 500 words, it must be self-contained, and it must not require reference to the paper to be understood.  In some cases, only the abstract of a paper is read; in other cases an abstract prompts further reading of the entire paper.  The abstract should present the primary objectives and scope of the study and the reasons for writing the paper; the techniques or approaches should be described only to the extent necessary for comprehension; and findings and conclusions should be presented concisely and informatively.  The abstract should not contain unfamiliar terms that are not defined, undefined acronyms, reference citations, or displayed equations or lists.

Footers

All pages of the submitted paper must have a footer. This footer must have:

• "year of contest" i.e. 200# LTPP-ASCE International Contest on LTPP Data Analysis
• Name of Author (1)
• Category
• Page number.

5.3 Evaluation Process

The following criteria will be used to evaluate all papers.

1. Usefulness of product - potential benefits to multiple end-users
2. Originality of concept (new/fresh technical topic)
3*. Demonstrated ample use of LTPP database
4. Organization of paper - completeness, references
5. Presentation - clarity, style, etc.

* Participants must use more than one LTPP site and data for the paper must only be based on LTPP data.

5.4 Review Process

A pool of reviewers consisting of the Transportation & Development Institute’s (T&DI) Task Committee on the LTPP contest and representatives from universities, industry, state agencies and the LTPP program staff (herein called “Contest Board”) will be appointed to evaluate the papers using the criteria outlined above.  The winners will be determined for each category in accordance to the classification described in Table 3.1.

5.5 Publication of Papers

Depending on the number of papers and range of scope, the FHWA may print the successful papers in a special report and may also place them on the FHWA web site.  Upon the completion of the review process, authors are encouraged to seek publication for their papers independently in ASCE journals, TRB records, or other appropriate publications.  A release form from the ASCE-LTPP Contest Task Committee will be issued to authors for publication purposes.  This form can be maintained through the ASCE/T&DI liaison (Andrea Baker, 703-295-6124, abaker@asce.org).

Paper Submission

Contestants should submit their papers to the Transportation & Development Institute (T&DI) of ASCE in electronic format only via e-mail. Diskette or CD can also be submitted, and must be sent to T&DI at the address shown below. In either case, the paper must reach T&DI’s office on/or before June 30, 2010. Each paper must have a cover page as described in Appendix B, and be submitted in MS Word format only.  Papers submitted in any other format will automatically NOT be considered!

E-Mail submission, send the paper file by e-mail to:

ASCE-LTPP Task Committee - LTPP Data Analysis Contest: ltpp@asce.org

Diskette or CD-ROM submission, send to:

American Society of Civil Engineers
Transportation & Development Institute
International Contest on LTPP Data Analysis
Attention: Andrea Baker/ ASCE-LTPP Task Committee
1801 Alexander Bell Drive
Reston, VA 20191-4400

The contest board will screen the papers to check eligibilities and duplicate papers.   The board will then transfer all files to Adobe Acrobat PDF format prior to sending to reviewers.  This is to ensure that contest papers and their contents are not lost or altered in the process of file copying and/or transfer via the e-mail.

Appendix A

Paper Preparation Guidelines

Cover page:
Insert a cover page that includes all authors’ names, affiliation and addresses. It should also list the contest category (as per table 3.1) for which the paper is submitted (see Appendix B). Papers are reviewed anonymously, and therefore, names and affiliations of authors should appear only on the cover page.

Faculty Advisor Sponsorship Letter
Following the cover page, a signed letter from the faculty advisor for participants in categories 1 and 2 should be included on the academic institution letterhead. The letter shall state his/her sponsorship of the student team and that he endorses their participation and that the paper contents were neither published nor submitted for publication elsewhere.

Abstract Page:
Following the cover page/or the faculty advisor sponsorship letter, insert an abstract page. It should include the paper title (authors names must not be included). The abstract shall be limited to a maximum of 500 words.

Paper Manuscript (limited to 7,500 words, including figures and tables, see item 5.2):

1. MAIN HEADING – LEVEL 1 CENTERED (Font: times new roman, 14 point, bold. All caps.)

1.1 Heading Level 2 – Left Justified
Font: times new roman, 14 point, and bold italic. Leave two spaces before and one space after.

1.1.1 Heading Level 3 – Left Justified
Font: times new roman, 12 point, underlined. Leave one space before and after.

Body Text:
Font: times new roman, 12 point. Single-spaced.

Footers
Font: times new roman, 10 point. Single-spaced., page centered

References
List references alphabetically by authors last names using the ASCE style.

Appendix B

Contest Paper Cover Page

International Contest on LTPP Data Analysis
"200#" Year,

Contest Entry for Category _______
(insert category number and name as per table 5.1 in the contest operation manual)

Paper Title
(INSERT THE PAPER TITLE USING MAIN HEADING FORMAT)

By:

Author 1 (main author) full name
Affiliation
Complete Address, Phone, Fax and E-mail

Author 2 full name
Affiliation
Complete Address, Phone, Fax and E-mail

and

Author 3 full name
Affiliation
Complete Address, Phone, Fax and E-mail

Faculty Advisor (if any)
Full name
Affiliation
Complete Address, Phone, Fax and E-mail

Consent:
This paper is submitted to the 200# ASCE-LTPP International Contest on LTPP Data Analysis, for Category No.? The authors certify that the paper contents were neither published nor submitted for publication elsewhere.