National Academies Press: OpenBook

Pavement Marking Warranty Specifications (2010)

Chapter: Chapter Two - Background and Context

« Previous: Chapter One - Introduction
Page 11
Suggested Citation:"Chapter Two - Background and Context." National Academies of Sciences, Engineering, and Medicine. 2010. Pavement Marking Warranty Specifications. Washington, DC: The National Academies Press. doi: 10.17226/14437.
×
Page 11
Page 12
Suggested Citation:"Chapter Two - Background and Context." National Academies of Sciences, Engineering, and Medicine. 2010. Pavement Marking Warranty Specifications. Washington, DC: The National Academies Press. doi: 10.17226/14437.
×
Page 12
Page 13
Suggested Citation:"Chapter Two - Background and Context." National Academies of Sciences, Engineering, and Medicine. 2010. Pavement Marking Warranty Specifications. Washington, DC: The National Academies Press. doi: 10.17226/14437.
×
Page 13
Page 14
Suggested Citation:"Chapter Two - Background and Context." National Academies of Sciences, Engineering, and Medicine. 2010. Pavement Marking Warranty Specifications. Washington, DC: The National Academies Press. doi: 10.17226/14437.
×
Page 14
Page 15
Suggested Citation:"Chapter Two - Background and Context." National Academies of Sciences, Engineering, and Medicine. 2010. Pavement Marking Warranty Specifications. Washington, DC: The National Academies Press. doi: 10.17226/14437.
×
Page 15
Page 16
Suggested Citation:"Chapter Two - Background and Context." National Academies of Sciences, Engineering, and Medicine. 2010. Pavement Marking Warranty Specifications. Washington, DC: The National Academies Press. doi: 10.17226/14437.
×
Page 16

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

11 PURPOSE This chapter provides background and context for the tech- nical findings in chapter three. The chapter is organized as follows: • An overview of the history of highway construction war- ranties in the United States, including the roles played by state DOTs and the FHWA in advancing warranty prac- tices generally and those with respect to pavement mark- ings specifically. • Reference to a warranty framework that was based on cumulative U.S. road construction experience to 1999. This framework synthesized categories of information believed to be useful when developing road construction warranties. Current examples of actual state DOT war- ranties for pavement markings that are discussed in chap- ter three and Appendix D generally conform to this frame- work, but illustrate the variety of specific approaches that agencies have used in implementing their respective warranty specifications. • A discussion of performance characteristics related to pavement markings, which helps in understanding tech- nical provisions of pavement marking warranties dis- cussed in chapter three and Appendix D, as well as cur- rent shifts toward more performance-based approaches when developing warranty specifications. Pavement markings were the first highway-related asset to be addressed through warranty specifications in recent U.S. road history. The historical review that follows shows that early experience with pavement marking as well as other types of road construction warranties provided useful experience on how to avoid obvious problems and prompted thinking about what information and requirements could be included in war- ranty specifications. HISTORICAL REVIEW Archived Sources The 1980s and 1990s saw the introduction and growth of trial use of road construction warranties in the United States. War- ranties during this period were used for road construction and maintenance on several types of highway assets including pavements, bridges, intelligent transportation system com- ponents and buildings, landscaping, pavement markings, sign sheeting, and roofing. Warranty durations ranged from 1 to 10 years across all types of work; for pavement markings, the warranties extended from 2 to 6 years. An FHWA website sum- marizes the experiences of 27 states in terms of highlights, war- ranty duration, performance indicators, and bonding and pay- ment provisions (“Briefing: Warranty Clauses . . .” 2000). A subset of these projects in 14 states was accomplished with FHWA assistance through the innovative contracting compo- nent of its Special Experimental Projects 14 (SEP-14) program. Following the passage of the Intermodal Surface Transporta- tion Efficiency Act (ISTEA, P.L. 102-240, Dec. 18, 1991), the FHWA subsequently engaged in a rulemaking process to allow the use of warranties on National Highway System (NHS) as well as non-NHS federal-aid projects. This rulemaking was completed successfully and went into force in 1996. Copies of many documents related to this early warranty research, as well as administrative changes during this period (e.g., Federal Register announcements as part of FHWA rule- making), are available on the technology transfer website for innovative contracting that is operated by Utah State Univer- sity (“Innovative Contracting” n.d.). Brief histories, discus- sions, or analyses of these research studies, their successes and failures, and the administrative actions during this period are available in several sources in addition to the FHWA web- site cited earlier. Among these are compilations of the status and use of road construction warranties in the United States and Europe as presented in NCHRP Synthesis 195: Use of Warranties in Road Construction (Hancher 1994) and a paper summarizing U.S. warranty experience by Russell et al. (1999). A study to develop performance-based warranties for the Vir- ginia DOT also reviewed work during this period as well as the concepts underlying warranty specifications (Ozbek 2004). A study conducted in 2001–2003 to update information on U.S. road construction warranties likewise briefly reviewed the warranty use experiments by state DOTs during the 1980s and 1990s (Bayraktar et al. 2004, 2006). Lessons Learned from Early U.S. Highway Warranty Use Overview Through 1999 An overview of U.S. warranty contracting for highway con- struction was developed by Russell et al. (1999). The first experiment with a highway warranty was for pavement mark- ings by the North Carolina DOT (NCDOT), beginning in 1987. CHAPTER TWO BACKGROUND AND CONTEXT

Only a handful of projects were completed through the early 1990s, but warranted work increased substantially in the late 1990s, spurred by passage of ISTEA and subsequent changes in federal regulation that allowed warranty use on federal-aid projects both on and off the NHS. From 1987 through 1997, 240 projects involving warranties were completed by 21 states, and Florida and Utah were planning to begin warranty use in 1998. The count of 240 projects was a conservative number, because DOTs were not able to provide an accurate tally of all the traffic marking, landscaping, and irrigation projects. War- ranty specifications in this initial 10-year period covered work on asphalt pavement, chip sealing, microsurfacing, patches on portland cement concrete pavement, bridge painting, bridge components, landscaping and irrigation systems, pavement markings, and roofs (Russell et al. 1999). For pavement marking specifically, agencies promoted quality of work by focusing on contractor qualifications and quality of materials and methods of application and installation. Specific requirements by DOTs included some or all of the following: personnel resumes, lists of materials and equipment to be used, test reports or manufacturer’s data on materials, annual performance reports, and manufacturer’s warranty of materials performance and, in some cases, of workmanship. The latter requirement typically included training of contrac- tor’s personnel who applied or installed the markings and onsite presence of a manufacturer’s representative during application. Other requirements might also include a traffic control plan, a striping plan giving the timing and area of each stage of work, a spill recovery plan, and a placement, procurement, and handling plan (Russell et al. 1999). Two project examples from this period provide additional insight into the outcomes of these early efforts. The first is the NCDOT project that warranted pavement markings; the second is a pavement (roadway surface) warranty initiative by the Wisconsin DOT (WisDOT). NCDOT: Pavement Marking Warranty In 1987, epoxy pavement marking materials were installed on a section of I-85 in central North Carolina, with the objectives of (1) monitoring the condition and performance of the mark- ings through a 4-year performance period, and (2) assessing the use of a performance-based warranty specification that could be applied on future NCDOT pavement marking projects (Stanley 1989, 1990). The warranty specification required that the markings meet or exceed criteria governing physical dura- bility and reflectance during the 4-year performance period. As the trial progressed, the basic mechanisms of the war- ranty specification appeared to work as planned. Most of the markings performed satisfactorily through the first two years. Sections of the yellow edge line that had incurred physical damage after one year of service were replaced promptly by the contractor. No other deficiencies attributable to the con- 12 tractor were observed after that. However, in the third year of the trial, the condition and performance of the markings were unexpectedly degraded by premature failures of the asphalt pavement surface. These problems required maintenance and resurfacing, which first reduced the effectiveness of the mark- ings and then obliterated them. The trial evaluation was halted after three years (Stanley 1990, 1991). While the logistical and administrative feasibility of pave- ment marking warranties was demonstrated, the results also showed the sensitivity of pavement marking performance to road maintenance work (Stanley 1991). • The pavement markings cracked as a result of reflection cracking and spalling of the underlying pavement surface. This cracking caused both a reduced presence (durability) and reduced retroreflectance. • The reflectance of the pavement markings suffered fur- ther from road maintenance and repair as evidenced through asphalt spotting and tracking from nearby crack sealing, short overlays, and pothole filling. Even small amounts of asphalt on the surface of pavement markings reduced their measured reflectance. WisDOT: Asphalt Pavement Warranties Useful lessons on how to structure and administer warranties also came from demonstration projects involving paved road surfaces. WisDOT engaged in trial use of asphalt pavement warranty specifications with assistance from the FHWA through SEP-14. This effort was an outgrowth of a WisDOT quality control/quality assurance program to give contractors a stronger role and greater responsibility in undertaking pave- ment work in the state. By 1994 almost all asphalt pavement being placed on the state trunk highway system came under this quality control/quality assurance program, and a warranty specification for asphalt concrete pavement construction was seen as the next logical step. The result indicated that war- ranty specifications could be developed and used successfully in connection with low-bid project procurements. Warranties added 5% to 10% to the cost of pavement projects over their 5-year duration, but reduced WisDOT’s construction engi- neering costs, gave contractors greater flexibility and control in managing their project work, and provided a quality pave- ment. Salient characteristics of this warranty program were as follows (Shober et al. 1996): • Purpose. WisDOT identified several purposes of this warranty program; for example, to move from method- based specifications to performance-based specifications; to reduce departmental costs of testing, supervision, and construction; to encourage contractor innovation; to ori- ent highway construction toward a performance-based process; to strengthen customer-oriented results in safety, ride quality, and asset longevity; to gain administrative and management experience in warranty-related matters

13 such as bonding; and to leverage the WisDOT pave- ment management system in helping define acceptable performance targets. • Duration. WisDOT considered warranty durations of from 3 to 5 years. A 5-year warranty was selected because it provided sufficient time to assess pavement perfor- mance without placing an undue burden on the contractor. • Performance indicators. Developing customer-oriented performance indicators for the warranty likewise involved balancing desired qualities with realistic warranty-based issues. Of eight measures considered initially, three were selected: rutting, friction, and longevity. These customer- oriented indicators were then related to technical cate- gories of pavement distress that are managed using Wis- DOT’s pavement management system. • Pavement management system contribution. Data from WisDOT’s pavement management system proved valuable in several tasks: (1) establishing realistic war- ranty performance thresholds based on historical data; (2) providing well-documented, proven methods of con- ducting distress surveys to establish pavement perfor- mance; (3) through its store of data, giving contractors and surety companies the confidence that what was being asked for in the warranty specifications was entirely achievable; and (4) giving the surety companies proven data on which to base a bond. • Conflict resolution. A conflict resolution team was estab- lished for each pavement project and empowered to resolve disputes between WisDOT and the contractor. • Agency and contractor practices. Both WisDOT and the contracting community applied practices that con- tinue to be reflected in warranted road construction. For example, WisDOT adhered to the principle that con- tractors would not be held responsible for distresses caused by factors beyond their control—an important perspective when considering the multifaceted causes of pavement distresses such as alligator cracking and rutting. Contractors developed a reliable approach based on established construction technology, avoidance of unreasonable risk, and a focus on quality. • Sense of opportunity. Contractors taking a long view of their business opportunities welcomed the use of war- ranties. Warranties gave the contractors a better under- standing of how pavements performed in service, and put long-term performance in their business interest. The greater latitude and responsibility they were given dur- ing construction enabled contractors to be more nimble and creative in solving problems. • WisDOT recommendations. Based on this experi- ence, Shober et al. (1996) recommended that WisDOT expand the warranty approach to other types of pave- ments, reevaluate and adjust performance thresholds as needed, and consider incentives for exceptionally well- performing pavements. If, for example, a pavement exhibited exceptional performance at the end of 3 years, the contractor could be relieved of future warranty work on that project. Such incentives were believed to be beneficial to all parties: the contractor would save on bonding and maintenance costs and WisDOT and the motoring public would have a superior performing pavement. More Recent Study of U.S. Construction Warranty Experience An updated picture of the use of road construction warranties in the United States was obtained through a study conducted in 2001–2003 (Bayraktar et al. 2004, 2006). Data were obtained through a literature review, survey questionnaire, and inter- views with personnel among selected transportation agencies, contractors, and surety companies. The survey questionnaire was cast broadly among 158 organizations in the United States. Sixty-three responses were received from 40 state DOTs, 16 contractors, and 7 bonding companies. These responses were culled to retain only the subset from agencies and firms that had solid experience with road construction warranties. Questionnaire responses were qualified in this way for 13 state DOTs, 16 contractors, and 6 surety companies. The survey was followed up with interviews of key individuals in transporta- tion agencies to clarify responses where needed and gain addi- tional information on perceived benefits of warranties, per- ceived barriers to implementation, preferred warranty duration for different types of work, typical bidders’ profiles, and pos- sible alternatives to then current warranty provisions. Contrac- tors and bonding companies were likewise interviewed on topics relevant to their experience and perspectives. Key results of the Bayraktar et al. study that relate to findings of this synthesis project are discussed in chapter three. FHWA Activities Following the passage of ISTEA in 1991 and final rulemak- ing in 1996, which together allowed use of construction war- ranties on federal-aid projects, the FHWA has maintained active support of warranty clauses. The information on the FHWA website regarding the historical development of con- struction warranties and state usage was discussed earlier. The FHWA has also sponsored international scans on Euro- pean warranty use, which are discussed in chapter three. In addition, the FHWA is conducting the following activities relevant to the subject of this synthesis: • The FHWA is sponsoring research by Utah State Uni- versity to study best practices in innovative contracting and to compile relevant sources on the Innovative Con- tracting website discussed at the beginning of this chap- ter (“Briefing: Warranty Clauses . . .” 2000; “Innova- tive Contracting” n.d.). It has also developed materials that provide an overview and explanations of warranty practices (“A New Look . . .” 2007; “Background for Pavement Warranties” n.d. draft). • The FHWA is meeting a Congressional mandate to develop minimum acceptable retroreflectivity thresholds

for pavement markings. Background information on this mandate and its importance is discussed in NCHRP Synthesis 371 (Markow 2007). Accomplishments to date are compiled on an FHWA Safety Program website (“Pavement Markings Visibility” n.d.) and an FHWA research website (“Establishing Criteria for Minimum . . .” n.d.). Technical and economic research contributing to this effort has been performed (Debaillon et al. 2007, 2008; Hawkins et al. 2008). Two workshops were con- ducted in Summer 2007 to solicit input from state and local transportation agency representatives regarding how the minimum retroreflectivity levels could be incorporated into the Manual on Uniform Traffic Con- trol Devices (MUTCD) (Falk and Carlson 2008). Work is proceeding on this effort. • The FHWA is conducting pavement marking demonstra- tion projects in Alaska and Tennessee that are required by Section 1907 of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU, P.L. 109-59, Aug. 10, 2005). The pur- pose, features, and funding of these demonstration proj- ects are described in an FHWA Fact Sheet (“Pavement Marking Demonstration Projects” 2006), with additional detail on a contractor website (“FHWA Project 475980- 00001 . . .” n.d.). Because the legislation specified a num- ber of requirements, the FHWA is conducting research in four major topic areas (“FHWA Project 475980-00001 . . .” n.d.): 1. Durability study: to investigate the cost-effective- ness of different pavement marking systems, includ- ing advanced acrylic waterborne markings. 2. Safety study: to evaluate the impacts and effective- ness of increasing the width of pavement marking edge lines from 4 in. to 6 in. 3. Environmental study: to evaluate the potential environmental impacts of the different pavement marking systems that are included in the demonstra- tion projects. 4. State bidding and procurement processes study: to review the effects of state bidding and procurement processes on the quality of pavement marking mate- rials that are employed in state highway projects. This website includes status reports describing progress and plans within each active topic area. Work is proceeding on these projects. WARRANTY FRAMEWORK DEVELOPED FROM HISTORICAL EXPERIENCE Based on a review of state highway warranty specifications covering various types of work through 1998, Russell et al. (1999) compiled a road construction warranty framework com- prising 11 key categories of information that were typically included: • A description of the warranty scope and work required. • The duration of the warranty period. 14 • Bonding requirements including bond value, accept- able bond rating, and other administrative and proce- dural requirements. • Maintenance responsibilities and work approvals. • Method of conflict resolution including requirement for a conflict resolution team, its composition, criteria for invoking the team’s involvement, and the resolution process. • Contractor responsibilities regarding the warranty including threshold performance values that trigger the need for remedial work, provisions governing materials and construction methods as applicable, the specified end product, elective or preventive maintenance actions, and insurance requirements. • Department (agency) responsibilities including bond and insurance approvals, inspection, approvals of work plans, reports, and work performed, and criteria and requirements to meet emergency situations. • Performance indicators that will be used to guide work needed under the warranty and criteria to deter- mine whether defects are beyond the contractor’s control. • Requirements for corrective actions including any agency approvals needed, the types of activities and allowable time period for remedial actions, and proce- dures that void the need for corrective action by the con- tractor (e.g., utility relocation or destructive testing by the department). • Method of measurement of the warranted end product. • Basis of payment; for example, amount, limits, and pay- ment schedule. Some details have advanced since 1998; for example, the introduction of contractor or third-party inspection in lieu of agency inspection during the warranty period and improved understanding of pavement marking perfor- mance. However, the basic structure of this framework, interpreted broadly, can provide a guide in formulating cur- rent warranty provisions. The examples of current pave- ment marking specifications included in Appendix D (included as a web-only document), with key aspects dis- cussed in chapter three, illustrate different ways in which these basic elements have been incorporated within con- temporary warranty specifications. PERFORMANCE ISSUES RELATED TO PAVEMENT MARKINGS Research and field experience with updated pavement marking materials and practices has accompanied the increasing use of warranty specifications for these markings. These concurrent advances have enabled DOTs to include more refined installa- tion and performance requirements, as well as provisions for items such as multi-year performance measures/criteria and staged payment schedules. The following subsection describes general categories of pavement marking performance typi- cally included in warranty specifications. Specific examples,

15 with threshold criteria and measurement procedures for var- ious marking materials, are given in Appendix D (web only). Later subsections summarize the current status of research on prediction models for pavement marking performance and impacts of pavement marking quality on road mobility and safety. Past experience with asphalt pavement warranties has shown these topics to be important issues in developing effec- tive warranty specifications. They continue to be important subjects of investigation and the focus of ongoing DOT interest regarding pavement marking performance and related benefits. Measures of Performance Pavement marking performance is commonly specified in war- ranties using the following measures. (These measures relate to the warranty period as defined in chapter one. Other measures may also be included in specifications, relating to initial accep- tance or observation or performance periods that precede the warranty period.) • Retroreflectivity, visibility: The visibility of pavement markings is critical to safety and the orderly movements and interactions among motor vehicles, bicyclists, and pedestrians. Retroreflectivity is the ability of marking materials to reflect light back to its source and can be mea- sured quantitatively by instruments. Warranties typically specify minimum retroreflectivity requirements (under dry, wet, or rainy conditions) through the warranty period, but may also allow for visual inspections in daytime or nighttime. Allowable minimum retroreflectivity levels are usually specified separately for white and yellow markings and, depending on individual agency practice, may or may not vary during the warranty period. Tech- nical discussions of retroreflectivity are contained, for example, in the FHWA Delineation Handbook (Migletz et al. 1994) and the synthesis of pavement markings research performed for the Iowa DOT (Thomas and Schloz 2001). The issue of the minimum level of reflec- tivity needed for safe and effective traffic movements has been a subject of continuing research and agencies have adopted different approaches and threshold values. • Durability: Durability, also referred to as presence, refers to the resistance of a pavement marking to physical dam- age; for example, cracking, chipping, breaking, spalling, flaking, blistering, crazing, delamination, shrinkage, loss of adhesion to the pavement surface, or other damage that causes the marking to appear worn out or unsightly. The durability of a pavement marking depends not only on the marking material, but also on traffic (average annual daily traffic), weather and resulting maintenance activity (e.g., winter maintenance), the quality of materials, preparation, installation, and the type and condition of the pavement surface. An issue in assessing durability is defining when a marking has degraded to the threshold that requires replacement. Agencies have adopted different approaches and threshold values for evaluating durability. • Color: Color retention or stability may be specified with reference to standardized color chips and color tolerance charts and, depending on agency practice, by providing chromaticity coordinate limits for use with a colorimeter. The warranty specifications may refer to test methods or standards of the International Commission on Illumina- tion [CIE (English acronym) or ICE (French)], ASTM International (originally the American Society for Test- ing and Materials), AASHTO, or other organizations. In addition to these color-related requirements, specifi- cations may also call for minimum daytime reflectance values for white and yellow markings, respectively. Examples of the use of these measures are provided in each of the specifications included in Appendix D (web only). Agencies also specify a number of administrative steps to promote quality, including meetings before and during the job; contractor submittal of work plans, spill plans, and progress status reports; and required testing by agencies noted previ- ously or the National Transportation Product Evaluation Pro- gram (NTPEP). Readers who would like additional informa- tion on the types of pavement marking materials in use today and measures of their performance can refer to a number of recent documents; for example, NCHRP Synthesis 306: Long- Term Pavement Marking Practices (Migletz and Graham 2002), Pavement Marking Handbook (Texas) (2004), “ODOT’s Pavement Marking Program” (Oregon) (2008), and the chapter on pavement marking materials, with cited references, in NCHRP Synthesis 371 (Markow 2007). Predicting Pavement Marking Performance The compilation of good historical data on pavement mark- ing performance and the ability to predict performance reli- ably would assist both public and private sector organizations to address warranty requirements more dependably and effi- ciently. This idea is suggested by experience to date in the pavement arena. • The earlier discussion of WisDOT’s pavement warranty experience shows the importance of good historical data on performance. Contractors and sureties have both gained confidence from these data in (1) the proven track record of existing WisDOT pavements, which provided realistic estimates of life expectancies; and (2) the like- lihood that warranty requirements were achievable by the contractor. • Pavement management systems, with predictive models based on periodic inspections and accumulated historical data, enable agencies to forecast trends in condition and the need for corrective work. The timing of maintenance and rehabilitation treatments can thus be optimized to provide satisfactory performance at the lowest long- term cost. • With an available model to predict performance (in the WisDOT pavement case, the AASHTO pavement design

model) researchers have formulated a method of risk- cost analysis that can be used by agencies and contractors to analyze short-term, warranty-based specifications for pavement projects (Zhang and Damnjanovic 2006). • Researchers have shown how a pavement management system can be used to track the performance of both warranted and nonwarranted pavement projects, and have demonstrated this approach in five states: Florida, Indiana, Michigan, Ohio, and Wisconsin (Wang et al. 2005). Work has already been undertaken to develop pavement marking management systems in Minnesota (Pavement Mark- ing Management System . . . 1999), Missouri (Weinkein et al. 2002), and Iowa (Hawkins et al. 2006). Work is proceeding on predictive models that can help analyze the factors affect- ing pavement marking performance and assist in making deci- sions on when corrective work might be needed; for example, Parker and Meja (2003) and Sathyanarayanan et al. (2008). This work tends to be performed for a single agency or at a single site. Indications from a survey of practice nationwide in the management of pavement markings suggests however that considerable variability will exist in comparing results from different agencies until models better account for a greater number of influencing variables, including road characteristics and driver behavior (Markow 2007). Impacts of Pavement Marking Performance The impacts of pavement marking performance in terms of effects on crash rates, for example, are likewise subject to variability, including sometimes apparently counterintuitive effects. At the heart of this issue is the relationship between retroreflectivity and crash rates, or retroreflectivity and drivers’ ratings of pavement marking acceptability. Although there is a broad relationship between the two variables in each of these pairs, it is confounded by details of the road site, traffic char- acteristics, and driver characteristics and behavior. This issue has been addressed in a number of sources and is reviewed, for example, in NCHRP Synthesis 306 (Migletz and Graham 2002) and NCHRP Synthesis 371 (Markow 2007). Although the literature on other types of warranties (particularly those for pavement projects) suggests no direct linkage between performance impacts and an agency’s ability to administer warranties, there would be a direct relationship between the impacts of asset performance and the presumed benefits or value-added owing to the warranty. For example, with respect to pavement markings specifically, further studies may be needed to determine whether pavement marking warranties contribute to safety by: • Maintaining a brighter line through the warranty period (because higher retroreflectivity leads to higher driver ratings of visibility and/or lower crash rates), or 16 • Contributing to a longer life of the warranted marking, implying that the greater safety is being achieved through additional safety benefits accumulated through the longer useful life, but not necessarily to greater brightness dur- ing the warranty period. Current research is ambiguous on this point (e.g., Bahar et al. 2006, in addition to references cited previously). A study in New Jersey suggests that there may be a “threshold effect” in which increases in retroreflectivity above this threshold value do not significantly affect drivers’ ratings of visibility (Parker and Meja 2003). Again, these issues relate to the justifications for warranty use and the potential benefits to be achieved, and not to the management or administrative aspects of warranty use. A somewhat analogous issue has been raised by Bayrak- tar et al., who noted that based on current warranty use in the United States, the practical outcome appears to be protection against premature failures rather than, say, promotion of contractor innovation or reduced life-cycle costs. This does not mean that such benefits cannot be achieved; rather, given the way in which warranties are now used, a main result is essentially that of an “insurance policy” (Bayraktar et al. 2006, pp. 4–6). Implications for Study Findings This evolving research in pavement marking performance and its impacts for road users is reflected in the variety of cur- rent state DOT practices documented in chapter three and Appendix D (web only). For example, agencies differ in the conceptual approach they take to warranty development. Only a few apply true performance-based concepts in which the specifications deal solely with required outcomes, leaving to the contractor the decisions on specific materials and methods of installation to achieve these requirements. The great major- ity of state DOTs that responded to the project survey employs rather a combination of prescriptive, methods-based materials and installation provisions, plus performance-based provisions covering the service life of pavement markings. Technical standards for satisfactory performance likewise vary across agencies in the measures of performance used as well as the numerical threshold values that define acceptable performance over time. Further distinctions are also found in particular aspects of warranty coverage; for example, the degree to which winter-related damage is regarded as the contractor’s or materials manufacturer’s responsibility, as opposed to exclusion of these factors from warranty requirements. Although broad-based com- parisons are highlighted in chapter three, the details of spe- cific provisions are purposely left for the reader to investi- gate in Appendix D. The reason is that it was believed important for the reader to understand the full context of each warranty specification when assessing specific tech- nical requirements.

Next: Chapter Three - Current Perspectives on Pavement Marking Warranties »
Pavement Marking Warranty Specifications Get This Book
×
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 408: Pavement Marking Warranty Specifications presents information on the use of pavement marking warranties by United States and Canadian transportation agencies, including agency specifications. European experience is also included in the report for comparison purposes.

Appendices D and E for NCHRP Synthesis 408 are available online.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!