Managing Selected Transportation Assets: Signals, Lighting, Signs, Pavement Markings, Culverts, and Sidewalks (2007)

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Transportation agencies at all levels of government have in recent years investigated and applied the concepts, methods, and tools of asset management. These applications have typi- cally focused agencies’ strongest capabilities on pavements and bridges, key items in an agency’s capital program and budget. They are often at the center of decisions on investment priorities and program tradeoffs, and their performance is highly visible to motorists and the public at large. Relatively sophisticated management systems and other analytic tools enable agencies to track the condition and performance of pavements and bridges and to identify “optimal” investment strategies for these assets. Data on current condition, performance, and remaining service life are developed through detailed, comprehensive periodic inspections. Broader technical knowledge of pavements and bridges is sustained through research pro- grams; technological innovation by public and private industry organizations; and information dissemination through publications, conferences, and courses. Similar methods, tools, and forums for information exchange are typically not as widely available or deployed for other surface transportation assets in the United States, at least not to the scale seen for pavements and bridges, although there are notable individual exceptions. The objectives of this synthesis were to gain a better understanding of the state of practice for managing transportation infrastructure assets other than pavements and bridges, to identify best practices, and to document gaps in existing knowledge and needs for further research. The study focused on the assets listed here, although unique or innovative management meth- ods for other assets were also included whenever identified. The six types of assets that were the primary subjects of this study—referred to as “selected infrastructure assets” or simply “selected assets”—included: • Traffic signals, including structural components; • Lighting, including structural components; • Signs, both ground-mounted (or roadside) and overhead, including structural components; • Pavement lane striping and other markings; • Drainage culverts and pipes (but not bridges); and • Sidewalks, including the walkway itself, curbs, and corners on urban roads and streets (corner curbs, and curb cuts and ramps if present). This synthesis study examined several key aspects of asset management related to the selected infrastructure assets, including primary sources of technical guidance for management; basic approaches to budgeting for and conducting preservation, operation, and maintenance; organizational responsibilities for ongoing maintenance; measurement of asset condition and performance, including methods and frequencies of data collection; estimates of service lives (or deterioration models) for key components of the selected assets, accounting for the differ- ent materials used; information technology capabilities available to help agencies manage these selected assets; perceptions of the transportation objectives that are served by maintaining selected assets in good condition; and major gaps in knowledge that impede better asset man- agement, with recommendations for future research. These data were gathered through a review of U.S. and international literature, and a survey of state, provincial, county, and city trans- portation agencies in the United States and Canada. SUMMARY MANAGING SELECTED TRANSPORTATION ASSETS: SIGNALS, LIGHTING, SIGNS, PAVEMENT MARKINGS, CULVERTS, AND SIDEWALKS

The literature review indicated that management of these assets can be complicated in several ways. • From an engineering and technical standpoint, selected assets comprise a number of components and materials, serve in many different environments across the United States and Canada, and are subject to many different types of deterioration. Developing models that adequately explain these deterioration mechanisms and that can predict ser- vice lives for the complete range of possible conditions is a major challenge. • From a human factors perspective, the selected assets that affect mobility and safety can have complicated impacts that are still being researched among different population groups of drivers and pedestrians. • From an organizational, institutional, and procedural view, selected assets present chal- lenges in management, coordination, and data compilation, given the typically diffused responsibility for their operation and maintenance. The survey questionnaire, developed with the advice of the Topic Panel, was presented in seven parts: six related, respectively, to the six classes of infrastructure assets listed ear- lier. A seventh part addressed the broader issues of asset management and knowledge gaps and needs. The survey was distributed to the contact individuals for asset management within each state department of transportation or state highway agency, as identified by AASHTO. Distribution to U.S. cities and counties was assisted by FHWA’s Local Technical Assistance Program network. Distribution to provinces and cities in Canada was facilitated by the Transportation Association of Canada. A total of 35 agencies responded to this questionnaire. Those agencies that responded to the survey were clearly interested in the management of these selected assets. Several have already developed management systems specifically directed at one or more of these classes of infrastructure. Others have incorporated these selected assets within agency-wide asset management systems or enhanced maintenance man- agement systems. Others are now in the process of developing an asset management approach for these assets, although they are not yet completed. At a minimum, agencies rely on existing maintenance management systems or other analytic and data gathering tools such as spread- sheet workbooks and paper log books to track and manage these selected assets. Agencies that responded to the survey agreed substantially on why these selected assets should be managed. Many provided exactly the same or very similar rankings of the transportation goals served by these assets. However, estimates of technical data such as asset service life varied across agencies. Although there is a basic pool of information that could form the nucleus of an asset management approach, these agencies reported that additional work is needed in a number of areas. • State of knowledge—current state of knowledge regarding the performance and service life of selected assets needs to be improved to reduce variability and increase consis- tency and completeness. • Inventory—lack of a complete, accurate, and current inventory of these selected assets was viewed by many agencies as one of the key issues to address. The main challenge is to keep the inventory complete and current over time. • Management capabilities and information—although research continues on understanding and modeling the service life of selected assets and implications for performance, participating agencies identified several additional capabilities and types of information that are needed to improve management. These included a need for greater standard- ization in how asset service life is measured and reported; the need to evaluate service life under field conditions; additional modeling tools and related information; and sim- ple, practical, and streamlined analytic tools to aid decision making without the need for substantial data gathering. 2

• Beyond physical condition—these selected assets demonstrate performance impacts that go beyond physical condition and service life. Measures of performance and life expectancy need to be broadened to encompass concepts such as energy consumption and functional, rather than physical, obsolescence of electronic components. Performance also needs to be understood in terms of impacts to the general public, not just motorists. • Dynamic commercial environment—new technology is continually evolving for these selected assets. Although these advances provide many benefits to transportation agencies and users, they complicate an agency’s ability to remain current regarding the performance and compatibility of new versus existing products. • Institutional factors—maintenance responsibilities for these selected assets tend to be shared among public- and private-sector entities. Although these arrangements may make efficient use of resources, they complicate information awareness and enforcement of maintenance standards. • New technology—several ideas were proposed by participating agencies for new tech- nology that could aid in the management and repair of selected assets. • Better communication of priority—participating agencies identified the need for stronger communication of the priority of selected assets. 3