Revista ingeniería de construcción
version ISSN 0718-5073
Rev. ing. constr. vol.27 no.1 Santiago 2012
Revista Ingeniería de Construcción Vol. 27 No1, Abril de 2012 www.ricuc.cl PAG. 93 - 111
Development of the new 2011 canadian pavement asset design and management guide: a brief summary of canadian state-of-the-practice
Susan L. Tighe*1, Norman W. McLeod*, Marta Juhasz**
* University of Waterloo, CANADA
** Alberta Transportation, CANADA
The development of the new 2011 Transportation Association of Canada (TAC) Pavement Asset Design and Management Guide (PADMG) began in September 2009. The project is a pooled fund study being sponsored by over twenty Canadian public agencies including all ten provincial Canadian Departments of Transportation, several major Canadian cities, several industry associations and the federal government. The effort is being lead by a Canadian consortium team composed of consultants and academics from across Canada. The consortium team is composed of a diverse group of practitioners who have experience across Canada in the various areas of expertise pertinent to this guide. The new 2011 PADMG will be an up-to-date, practical consolidation of Canadian pavement design and management practice for practicing engineers, managers and technicians. It will also be a valuable resource for college and university courses both in Canada and elsewhere. The guide will highlight key industry issues such as sustainability, climate change, and new innovations. The paper first provides a summary of findings from a stakeholder survey to determine current state-of-the-practice in Canada. Information collected in this survey covers the major practices areas in pavement design and management. There will be 15 chapters in the new guide ranging from discussions on the principles of asset management, to data requirements, sustainability, maintenance, materials, low and high volume road design and life cycle analysis of pavement designs. The draft 2011 PADMG has been submitted and the project will be completed by September 2011
Keywords: Transportation association of Canada (TAC), Pavement asset design and management guide (PADMG)
The development of the new 2011 Transportation Association of Canada (TAC) Pavement Asset Design and Management Guide (PADMG) began in September 2009.
The project is a pooled fund study being sponsored by over fifteen Canadian public agencies including all ten provincial Canadian Departments of Transportation, several major Canadian cities, several industry associations and the federal government. The effort is being led by a Canadian consortium composed of consultants and academics from across Canada. The consortium is composed of a diverse group of practitioners who have experience across Canada in the various areas of expertise pertinent to the Guide. The new 2011 PADMG is an up-to-date, practical consolidation of Canadian pavement design and management practices for practicing engineers, managers and technicians. It will also serve as a valuable resource for education of new engineers and technicians at both the college and university level. It is anticipated as was the case with previous guides that it will be used by international practitioners as a reference. The Guide will highlight key industry issues such as sustainability, climate change, and new innovations.
This type of initiative is not new to the TAC. Three previous guides have been published in 1965, 1977 and 1997. Full use of time invariant material from the 1997 TAC Pavement Design and Management Guide will be made, while outdated information will be removed. New material, concepts and practices, as well as new chapters, will be incorporated in the 2011 PADMG. In essence, the work to be carried out will build on the past but focus on the needs of the future.
2. Scope or objective of the paper
The focus of this paper is to address how the 2011 survey outcomes have influenced the process of producing the Guide. The survey helped to identify and subsequently address important issues related to pavement and asset management throughout Canada. This paper shows the 2011 survey results in comparison to the 1993 survey results. This shows the changes that have occurred in the past 18 years. Finally, the paper provides a brief introduction of the topics included in the new 2011 Guide.
One of the first major tasks in the development of the new 2011 PADMG was to carry out a stakeholder survey to determine the current state-of-the-practice in Canada. The intent of the survey, completed in early 2010, was also to ensure the content of the 2011 Guide is up-to-date and relevant to users.
This paper is directed at briefly describing the new Guide, summarizing the key findings from the survey, and providing a comparison of the 1997 Guide survey results to the new Guide's survey results (note that the 1997 Guide's survey was done in 1993). Information collected in the 2010 survey covers the major practice areas in pavement design and management. The comprehensive survey included questions on: network information; pavement and asset management practices; data collection types and methodologies including condition indices; pavement design, construction and materials; pavement preservation, maintenance and rehabilitation practices; new innovations; and select questions on green initiatives and sustainability.
The members of the consortium team, in partnership with the TAC PADMG Project Steering Committee, (PSC) have also identified the prospective chapters in the new Guide. Members of the consortium are currently reviewing reference materials both nationally and internationally to ensure each chapter is relevant and up-to-date. For example, the new Guide will include extensive review of TAC publications, Canadian Technical Asphalt Association (CTAA) proceedings, the Canadian National Guide for Sustainable Municipal Infrastructure (NGSMI), Transportation Research Board (TRB) records, the United States National Highway Cooperative Research Program (NCHRP), Provincial Standards, and other applicable publications. In addition, a list of additional references will be included at the end of each chapter.
The following chapters will be included in the new Guide:
• Chapter 1: Introduction;
• Chapter 2: Principles of Asset Management;
• Chapter 3: Principles of PMS and Implementation;
• Chapter 4: Data Requirements and Collection Methods;
• Chapter 5: Network Level Needs Analysis and Priority Programming;
• Chapter 6: Materials;
• Chapter 7: Flexible Pavement Design;
• Chapter 8: Rigid Pavement Design;
• Chapter 9: Gravel and Surface Treated Road Design;
• Chapter 10: Maintenance and Rehabilitation Treatments;
• Chapter 11: Life Cycle Analysis of Pavement Designs;
• Chapter 12: Role of Construction;
• Chapter 13: Role of Maintenance;
• Chapter 14: Sustainability in Pavement Engineering and Management; and
• Chapter 15: Issues, Opportunities and Future Prospects.
A detailed schedule for drafts was prepared to ensure the final 2011 PADMG was completed on time in September 2011. Each chapter was prepared by a team of two to three consortium members. Peer review by the consortium project manager and one other consortium member was also carried out on each chapter. A technical editor was also involved in the review of each chapter to ensure the Guide was professional and consistent. Finally each chapter was submitted to the PADMG PSC for their review and comment. The 2011 TAC PADMG was written in a straightforward and consistent manner so that it would be easy to understand. Each chapter was prepared to provide information for the newly graduated engineer or technician starting their career to the senior engineers and managers who require information on complex issues.
In addition, training and workshop materials were prepared by the consortium. This includes a comprehensive set of slides and speaker notes for use during the 2011 TAC Workshop at the annual fall conference and in addition, training across Canada has been planned upon the official release of the 2011 PADMG.
A primer for the 2011 PADMG was also prepared. The primer is directed at summarizing the key pertinent features of the Guide and is also directed at non-technical practitioners, executives and politicians responsible for managing assets. However, it will also serve as a communication tool for technical practitioners when dealing with their various stakeholders. The Primer outlines the key subjects that are addressed in the Guide and briefly describes the current status of Canadian best practices and emerging trends including technology advancements.
Green transportation technologies, climate change, and other topical technologies are highlighted. The Primer also highlights the importance of various factors involved in the design and management of all pavements in the network including: rural and urban; gravel, surface treated, flexible and rigid; and local, collector, arterial and freeway functional classifications.
4. Purpose and design of the 1993 and 2010 surveys
The surveys, carried out in both 1993 and 2010, were directed at acquiring information on current pavement design and management methods and practices and to identifying the preferences of requirements of a representative set of major users of the Guide. The surveys were also similar in format in both years (Tighe, 2009b). Another objective of the surveys was to identify problems or issues currently associated with pavement management systems, what could be done differently, and opportunities for change. Finally, the 2010 survey provided an opportunity for respondents to indicate items they would like to see in the new 2011 Guide.
The 2010 survey, developed by the consortium, was 32 pages in length and quite in-depth and comprehensive. The survey contained 9 major sections which were: General Information; Pavement and Asset Data Requirements, Collection Methods and Database; Network Level Needs Analysis and Priority Programming; Pavement Materials and Drainage; Pavement Design (Structural and Economic Evaluation); Construction; Maintenance and Preservation; Implementation of a Pavement Management and Asset Management System; and Issues, Opportunities and Future Prospects. Within each section there were items related to the information and also items for opinions or additional comments.
5. Respondents to the survey
The survey was distributed in January 2010 to organizations across Canada, including cites, provincial, federal and territorial agencies, consulting firms, academic institutions and other organizations associated with the field of pavement design and management. The return rate of the survey was 63% as opposed to a return rate of 75% for the 1993 survey, although the raw number of surveys returned in 2010 was higher, at 44, than in 1993, at 34. A broader group was surveyed in 2010 when compared to 1993 (Tighe, 2009b). The breakdown of respondents is shown in Table 1 below.
The survey was distributed in January 2010 and all responses were received by March 2010. In total, 44 surveys were received back from 15 cities, 14 federal, provincial and territorial agencies, 8 consultants and supplier agencies, 4 academic institutions and 3 Associations and Public Private Partnerships. It is noteworthy that the survey has also assisted the TAC Asset Management Task Force and the TAC Project Steering Committee on performance issues. It has also been used by the TAC Project Steering Committee on Special Roads.
Table 1. Summary of 1993 and 2010 Survey Respondents
6. Summary of 2010 survey findings
The following is a highly summarized overview of the survey responses, the findings of which will be incorporated into the new Guide. The results are grouped into Cities, Provincial/Federal/Territorial Agencies and Others. The questions that were asked are presented followed by the results. Due to the scope of this paper only selected responses have been summarized, the findings are presented in tables and figures. A more detailed version of the survey summary is also available through TAC (Tighe, 2010a; Tighe and Juhasz, 2010a). The intent of this section is to highlight current practices related to pavement management in Canada.
6.1 General Information
What percentage (of your average annual budget for roads and pavements) is directed to: new pavement construction/reconstruction, rehabilitation, routine maintenance, major maintenance and pavement preservation?
Figure 1. Summary of road and pavement spending for federal/provincial/territorial agencies
Figure 2. Summary of road and pavement spending for cities surveyed
Approximately what percentages of pavements are: gravel, surface treated, flexible (asphalt), rigid and composite?
Figure 3. Summary of pavement types for federal/provincial/territorial agencies
Figure 4. Summary of pavement types for cities surveyed
Table 2. What planning horizons or periods do you use?
Pavement and Asset Data Requirements, Collection Methods and Database.
Table 3A. Is your pavement database integrated with an asset management system?
Table 3B. If no, Do you plan to do so in the next 5 years?
Table 4. What is the location referencing system your agency currently uses?
Table 5. Is your database part of a GIS that incorporates, for example, underground services (where applicable), other road features etc.?
Table 6. Does your database accommodate dynamic segmentation?
Do you use the following?
Table 7A. International Roughness Index
Table 7B. Structural Adequacy Index
Table 7C. Response to the type of scale the agencies use for the Structural Adequacy Index
Table 7D. Surface Distress Index
Table 7E. Response to the type of scale the agencies use for the Surface Distress Index
Table 7F. Composite Index
Table 7G. Response to the type of scale the agencies use for their Composite Index
Table 7H. Response to the type of Composite Index used by the agencies
Table 8. Do you conduct periodic axle load surveys?
Table 9. Do you specifically incorporate any environment or climate related data in your pavement or asset management database?
Table 10. How do you handle or incorporate cost data on pavement construction or rehabilitation within your PMS (i.e. annual compilation of average or benchmark unit costs, etc)?
Table 11. Has your agency developed a network level PMS
Pavement Design (Structural and Economic Evaluation)
Table 12A. Does your agency have a Pavement Design Manual?
Table 12B. If yes, does it include rehabilitation design?
Table 12C. If yes, does it include maintenance?
Table 12D. If yes, does it include preservation?
Table 12E. If yes, does it include drainage design?
Implementation of a Pavement Management and Asset Management System.
Table 13. Pavement management can be operationally carried out at two basic levels: network and project. If you have implemented a pavement management system, does it consider:
Table 14. Are you planning any major changes in your PMS?
Table 15. Does it operate at the strategic level to produce one consolidated budget list for all assets?
Table16. Do all management systems feed into the AMS?
6.2 Issues, Opportunities and Future Prospects
This section is directly from the 2011 survey and the results are consolidated into the following list.
Describe what consultants or researchers could do to assist with tools your agency is lacking:
• Provide support in developing long-term performance specifications and design for pavements
• Asset Management System, including right-of-way asset management and underground utilities
• Focus research in defining the "sweet spots" on the deterioration curve which optimizes the timing of various preventative or rehabilitative treatments
• Issues related to funding constraints, and lack of resources for people and project follow-up, and loss of in-house expertise
• High speed and high quality data collection techniques relating to pavement distress and deflection
• Pavement design issues such as dependable backcalculation method/software and development of mechanistic design protocols to address use of non-traditional construction materials (e.g. cement stabilized granular, cold-in-place, hot-in-place, etc.)
• Methods to detect frost problem (discrimination between surface and deep frost problem), profile survey in winter and classification and frost measurement of frost cracking.
Any items that should be included in the new 2011 PADMG:
• Municipal constraints (e.g. curb and gutter, utilities) and a holistic management approach
• High speed and automated data collection such as IRI for QA, cracking data that has been collected using automated means
• Monitoring and evaluation procedures of rehabilitation/recycling techniques
• Structural characterization for Asset Management inputs to augment current inputs
• Pavement design related issues such as transition from dynaflect to FWD, implementation of the MEPDG into pavement design, mechanistic designs and protocols and also how to implement structural characterization into a strategic and tactical asset management models and life cycle costing
• Environmentally sustainable and more environmentally friendly road materials and systems such as a green pavement rating system, more usage of RAP, warm mix and half-warm mix asphalts
• Performance based on remaining life, life cycle economic evaluation and investment strategies, optimization of rehabilitation budget to maximize the enhancement of the network quality, and best practices to narrow down differences between the network level and project level analysis
• Practical aspects of PMS implementation
• Innovative recycling methods
• Thin surfacing, micro-surfacing
• Trench cut restoration issues and at intersections on downhill grades
7. Summary and comparison of the 1993 and 2010 surveys
The following summarizes and compares the 1993 and 2010 survey responses. Although responses were also received from non-road authorities, the responses below are from road owners only and exclude public private partnerships.
7.1 General Information
Planning horizons range from 1 to 10 years with most using 1 to 5 years in 1993 and 3 to 5 years for the 2010 survey. Rehabilitation, maintenance and preservation dominate pavement expenditures.
Table 17. Summary of the percentages spent on rehabilitation, maintenance and preservation
7.2 Pavement and Asset Data Requeriments, Collection Methods and Database
Table 18. Summary of the main measurement devices used by agencies
7.3 Network level needs analysis and priority programming
7.4 Implementation of a Pavement Management and Asset Management System
Table19. Summary comparison of examples of items for major changes in PMS
7.6 Issues, Opportunities and Future Prospects
8. Conclusion and future steps
This paper describes a large initiative that is currently underway to develop the new 2011 PADMG. This paper has presented a brief overview of the new 2011 PADMG and the findings from both the 1993 and 2010 surveys. Some of the detailed findings from the 2010 survey have been presented. These findings are intended to be highlights of the more comprehensive survey summary.
Perhaps one of the most surprising findings from the 2010 survey is in fact that despite a maturing road network, a large percentage of agency budgets seems to be allocated to new construction. Another notable change is that agencies are using slightly longer planning horizons in 2010 and are using PMS more extensively as compared to 1993. Several other smaller differences were noted between 1993 and 2010 and appear to primarily relate to changes in experience, expertise and the evolution of pavement design and management practices. With respect to issues opportunities and future prospects, generally the high priority areas remain unchanged from 1993 to 2010 with a greater emphasis in 2010 on the environment and the availability (or lack thereof) of skilled people.
The survey was very important for determining what information should be included in the design guide. It also provided valuable insight into general practices across Canada. The TAC Asset Management Task Force and a performance measures Steering Group has used the survey results for various inititives. Finally, the new 2011 Guide promises to be a valuable tool for practitioners, managers and educators both nationally and internationally.
The authors of this paper gratefully acknowledge the contributions of all the members of the consortium and the members of the Project Steering Committee. The efforts of Laura Bland, Administrative Assistant, at the University of Waterloo and the staff members at TAC are also appreciated.
Tighe S. (2009a), "Development of a National Pavement Asset Design and Management Guide (PADMG), Canada Consortium Proposal", Transportation Association of Canada. [ Links ]
Tighe S. (2009b), "Inventory Survey of Current Practices for Use in Preparing Transportation Association of Canada's New: Pavement Asset Design and Management Guide (PADMG)", Transportation Association of Canada. [ Links ]
Tighe S., Bland L., (2010a), "Pavement Asset Design and Management Guide, State-of-the-Practice Survey Summary". [ Links ]
Tighe S., Juhasz M., (2010a), "Canadian Pavement Design and Management Current State-of-the-Practice", Transportation Association of Canada Annual Conference, Halifax, Nova Scotia, Septiembre 2010. [ Links ]
Contribution ICMPA 2011
Contribution ICMPA 2011