MD-07-SP708B4FMartin O’Malley, GovernorAnthony G. Brown, Lt. GovernorJohn D. Porcari, SecretaryNeil J. Pedersen, AdministratorSTATE HIGHWAY ADMINISTRATIONRESEARCH REPORTDEVELOPMENT OF FRICTION IMPROVEMENT POLICIES ANDGUIDELINES FOR THE MARYLAND STATE HIGHWAYADMINISTRATIONPRINCIPAL INVESTIGATOR:RICHARD SPEIR, P.ERESEARCH TEAM MEMBERS:TARA PUZINROBERTO BARCENA, P.EPRAVEEN DESARAJU, P.EAPPLIED RESEARCH ASSOCIATES, INCSP708B4FFINAL REPORTFebruary 2009
The contents of this report reflect the views of the author who is responsible for the facts and theaccuracy of the data presented herein. The contents do not necessarily reflect the official views orpolicies of the Maryland State Highway Administration. This report does not constitute a standard,specification, or regulation.
Technical Report Documentation Page1.Report No.2. Government Accession No.3. Recipient's Catalog No.MD-07-SP708B4F4. Title and Subtitle5. Report DateDevelopment of Friction Improvement Policies and Guidelines for theMaryland State Highway AdministrationFebruary 20096. Performing Organization Code7. Author/s8. Performing Organization Report No.Richard Speir, Tara Puzin, Roberto Barcena, Praveen Desaraju9. Performing Organization Name and Address10. Work Unit No. (TRAIS)Applied Research Associates, Inc.7184 Troy Hill Drive, Suite NElkridge, MD 2107511. Contract or Grant No.12. Sponsoring Organization Name and Address13. Type of Report and Period CoveredSP708B4FMaryland State Highway AdministrationProject Planning Division707 North Calvert StreetBaltimore MD 21202Final Report14. Sponsoring Agency Code(7120) STMD - MDOT/SHA15. Supplementary Notes16. AbstractThis policy and guideline document presents the research performed and the activities that were undertakento develop guidelines and improvement policies for the implementation of a friction management programat the Maryland State Highway Administration (MDSHA). The document includes a review of the stateof-the-practice based on an extensive literature review. The Pavement Friction Management Frameworkand an overview of Friction Management have been included, and served as the basis for developing ourrecommendations for MDSHA’s pavement friction management program. In addition, using ourknowledge of MDSHA’s current friction practices and available data, a systematic approach to selectfriction improvement candidates as well as establishing state-wide friction policies to maximize MDSHA’savailable resources has been developed. Also, feedback from various MDSHA Districts and officials aboutfunding and scheduling preferences was obtained through various brainstorming meetings. The reportincludes various recommendations based on the results of this study, and suggestions for future datacollection practices and friction restoration methods have been included.17. Key Words18. Distribution Statement: No restrictionsPavement Friction, Pavement Texture, This document is available from the Research Division uponInvestigatory Level, Intervention Level, request.Friction Site Categories, FrictionRestoration Methods, Friction Number,International Friction Index, FrictionTesting.19. Security Classification (of this report)None20. Security Classification (of this page)NoneForm DOT F 1700.7 (8-72) Reproduction of form and completed page is authorized.21. No. Of Pages 22. Price53
TABLE OF CONTENTSINTRODUCTION . 3Background and Objective. 3Report Organization. 3LITERATURE REVIEW . 5Pertinent Literature Summary. 5PAVEMENT FRICTION MANAGEMENT FRAMEWORK . 6Pavement Friction . 6Friction Components. 6Factors Influencing Pavement Friction. 7Pavement Surface Texture . 8Friction Data Collection. 9PAVEMENT FRICTION MANAGEMENT OVERVIEW . 11Friction Categories and Levels . 11Establishing Investigatory and Intervention Friction Levels . 12Detailed Site Investigation. 16Project Selection . 17PFM Program Progress . 17CURRENT AND PROPOSED MDSHA FRICTION GUIDELINES ANDIMPROVEMENT POLICIES. 18Current Friction Practices in Maryland. 18Friction Data Collection and Observation . 19Candidate Safety Improvement Sections (CSIS). 19Current Friction Guidelines . 19Proposed MDSHA Friction Guidelines and Improvement Policies . 21Friction Program Development Guidelines- General Implementation. 21Friction Program Development Guidelines- for Immediate Implementation. 25Project Level Program Development Guidelines . 28Restoration Methods . 29Additional Network Level Friction Improvement Policies . 34Materials and Texture Testing and Selection. 35FEEDBACK FROM MDSHA DISTRICTS AND OFFICALS. 38Timings/Schedule . 38Funding Sources. 38RECOMMENDATIONS. 391
LIST OF FIGURESFigure 1: Adhesion and Hysteresis (2) . 7Figure 2: Type of Surface Friction(2) . 8Figure 3: Establishing Friction Levels Using Historical Friction Data Only(2) . 14Figure 4: Establishing Friction Levels Using Historical Friction and Crash Data(2) . 14Figure 5: Establishing Friction Levels Using Pavement Friction Distribution and CrashRate Friction Trend (2) . 15Figure 6: Friction Assessment Process . 22Figure 7: Friction Assessment Based on MDSHA’s Current Friction Rating System . 27Figure 8: Project Level Friction Assessment Process. 29Figure 9: Friction Restoration Methods. 33LIST OF TABLESTable 1: Factors Influencing Pavement Surface Friction(2) . 7Table 2: Factors Affecting Pavement Surface Texture(2). 9Table 3: Factors Affecting Friction Testing(2) . 10Table 4: Friction Categories and Levels for New Zealand(2, 10) . 12Table 5: Detailed Site Investigation Questions and Concerns(2,6,11,12) . 17Table 6: MDSHA’s Friction Practices(2) . 18Table 7: Friction Levels for Future Implementation(11) . 23Table 8: Friction Levels Using MDSHA’s Current Friction Ratings . 25Table 9: Friction Levels Based on Roadway Functional Class . 34Table 10: Schedule for the Friction Management Program. 382
DEVELOPMENT OF FRICTION IMPROVEMENT POLICIES ANDGUIDELINES FOR MDSHAINTRODUCTIONBackground and ObjectiveThe Maryland State Highway Administration (MDSHA) monitors friction properties ofpavement surfaces statewide. Additionally, each year the Office of Materials Technology(OMT) and the Office of Traffic and Safety (OOTS) work together to identify pavementlocations that have exhibited inadequate friction levels and relatively high numbers ofwet surface accidents throughout the state. Although there is a process in place to identifythese locations, the process is somewhat informal and inconsistent across the variousMDSHA District Offices.As a result of the MDSHA friction measurement and wet accident related activities,District Offices are required to prioritize and take action to address the noted locations.Consequently, the Districts should be given more guidance on how to better identifyproject candidates, and what actions can be taken to address these locations, includingmaterial selection, design life, and alternative temporary low-cost effective solutions untila more permanent fix can be applied. The objective of this study is to develop asystematic approach to select friction improvement candidates as well as establish statewide friction policies to maximize MDSHA’s available resources.Report OrganizationThis report has been divided into the following 7 sections:188.8.131.52.5.INTRODUCTIONLITERATURE REVIEWPAVEMENT FRICTION MANAGEMENT FRAMEWORKPAVEMENT FRICTION MANAGEMENT OVERVIEWCURRENT AND PROPOSED MDSHA FRICTION GUIDELINES ANDIMPROVEMENT POLICIES6. FEEDBACK FROM MDSHA DISTRICTS AND OFFICIALS7. RECOMMENDATIONSINTRODUCTIONThe Introduction contains important background information, the project objective, andthe report organization for this study.LITERATURE REVIEWThe Literature Review includes information about the literature search and provides asummary of the documents reviewed that were most pertinent to this study.3
PAVEMENT FRICTION MANAGEMENT FRAMEWORKThis section provides information about the basic concepts of pavement friction andsurface texture, which are key concepts to understand pavement friction, and pavementfriction management. This section also provides friction data collection information andcovers the MDSHA current friction practices, both of which are part of the frictionmanagement framework.FRICTION MANAGEMENT OVERVIEWThe friction management overview section includes important general information that isnecessary for developing a friction management program. Essentially, the informationpresented in this section can be used by MDSHA to improve upon various frictionmanagement entities using MDSHA specific data. Furthermore, this section outlinesimportant information on detailed site investigations, project selection, and frictionrestoration methods. It also covers the importance of documenting the frictionmanagement program’s progress for system feedback.CURRENT AND PROPOSED MDSHA FRICTION GUIDELINES ANDIMPROVEMENT POLICIESThis section presents the current and proposed friction guidelines and improvementpolicies developed for MDSHA. This section includes two sets of distinct guidelines forfriction management. The first set includes all of the entities of a state-of-the-art frictionmanagement program and should be considered as the goal system for futureimplementation. The second set of guidelines was developed using MDSHA’s currentfriction ratings and is applicable for a more immediate implementation. This section alsoincludes an additional friction improvement policy that exclusively addresses frictionnumbers at a network level. Additionally, this section includes information on materialtesting and selection, important aspects for setting and implementing friction policies,both on a network level and project level.FEEDBACK FROM MDSHA DISTRICTS AND OFFICIALSThis section contains information from the brainstorming meetings held with the DistrictOffices and other MDSHA officials. This section also provides a brief summary of thepreferred schedule of events and funding sources for friction projects based on thefeedback received at the brainstorming meetings.RECOMMENDATIONSVarious recommendations to help MDSHA improve their friction practices are presentedin this section of the report.Additional Information in the ReportThe report also contains 2 appendices: Appendix A, which includes a complete literaturereview and documents the sources utilized during the information gathering process.Appendix B includes an example form that could be used as aid for the detailed siteinvestigation/field survey.4
LITERATURE REVIEWAs a basis for creating guidelines and