plished in 2006 through five tasks stipulated in the research project statement. Data gathering used a breadth and depth approach. The study began with a literature review (Task 1), international in scope. Task 2 con- sisted of interviewing persons knowledgeable about the bleeding and flushing problem. Brief interviews were conducted with chip seal experts throughout the United States, including academicians, representatives from other state DOTs, binder suppliers, pavement preservation experts, and industry contacts. This work provided a practical, national-level context for addressing the bleeding and flushing problem. The research focus then shifted to an in-depth study of mainte- nance practices in Texas. In Task 3, face-to-face interviews were conducted with Texas DOT maintenance personnel to clarify the data and to gain additional, more subjective information not amenable to questionnaire responses. More than 120 Texas DOT personnel par- ticipated in on-site interviews, allowing for the capture of extensive construction and maintenance experience. In Task 4, results of the literature review and the statewide data-gathering efforts were tab- ulated, summarized, and synthesized. Task 5 constituted submittal of final project reports (1, 2). FINDINGS Maintenance Perspectives on Bleeding Versus Flushed Chip Seals Bleeding and Flushing Mechanism In a serviceable chip seal, binder performs its function of sealing the roadway surface against moisture infiltration and other envi- ronmental effects. However, the aggregate particles perform their function of creating a skid-resistant surface and keeping vehicle tires out of the asphalt. From a systems perspective, the asphalt binder protects the road, and the aggregate particles protect the binder. But for various reasons, the binder may migrate to the sur- face of the aggregate, filling the voids. This situation—inadequate voids between the aggregate particles—can manifest itself as either bleeding or flushing. Bleeding and flushing are related in that both mechanisms describe a condition whereby asphalt binder rises above the surface of the chip seal aggregate. This probably explains why most pavement mainte- nance publications, both academic and operations oriented, treat the terms more or less interchangeably (3–13). However, one of the prin- cipal findings of this research is that maintenance perspectives on bleeding and flushing in chip seals differ. Thus, the terms should be differentiated. Chip Seal Maintenance Solutions for Bleeding and Flushed Pavement Surfaces William D. Lawson and Sanjaya Senadheera 61 This study summarizes the research directed at identifying maintenance solutions for bleeding and flushed pavements surfaced with a chip seal. Factors that contribute to bleeding and flushed chip seals pertain to aggregates, binders, traffic, environment, and construction. No better advice exists for dealing with bleeding and flushed chip seals than to avoid the problem from the outset by employing a preventive mainte- nance perspective. Bleeding is an immediate maintenance problem that must be addressed; corrective maintenance, or in some cases emergency maintenance, would be done. Basic approaches to treat bleeding include bridging over the live asphalt by applying aggregate of various types and gradations, cooling off the pavement surface by applying water with or without additives, and removing the bleeding asphalt and rebuilding the pavement seal. Flushing, in contrast to bleeding, is typically not a mainte- nance problem that must be addressed immediately. Basic approaches to treat flushed chip seals are to retexture the existing surface or to add a new textured surface over the flushed pavement. Three promising areas for further research and implementation relative to bleeding and flush- ing solutions include the uses of lime water, ultrahigh pressure water cutting, and the racked-in seal at intersections. Expressed in the context of chip seal best practices, this study doc- uments typical manifestations of bleeding and flushing, discovering the causes and underlying factors that contribute to the problem, and identifying cost-effective treatment approaches. Three factors define its scope. First, the research intentionally focuses on the maintenance perspective to bleeding and flushing prob- lems. Second, this report specifically focuses on chip seals. Bleeding and flushing issues for hot-mix asphaltic concrete pavements have been intentionally excluded from consideration. Third, the mainte- nance solutions discussed largely derive from experience with roads in the Texas Department of Transportation (DOT) system. Although Texas physiography is diverse, by virtue of its being located in the southern part of the United States, the discussion in this paper does not heavily go into issues of cold-weather maintenance. METHOD The research method consisted of gathering, synthesizing, and reconstituting observational data from literature, survey question- naires, and field interviews. Research and reporting were accom- Department of Civil and Environmental Engineering, Texas Tech University, Box 41023, Lubbock, TX 79409-1023. Corresponding author: W. D. Lawson, william.d.lawson@ttu.edu. Transportation Research Record: Journal of the Transportation Research Board, No. 2108, Transportation Research Board of the National Academies, Washington, D.C., 2009, pp. 61–68. DOI: 10.3141/2108-07