Managing Selected Transportation Assets: Signals, Lighting, Signs, Pavement Markings, Culverts, and Sidewalks (2007) / Chapter Skim
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Pages 48-65
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From page 48... ...
49 OVERVIEW Signs help inform, guide, and regulate traffic, including vehicular traffic, pedestrians, and cyclists. Good signage must communicate its information clearly and with sufficient lead time to transport system users in daytime and nighttime and in variable weather conditions.
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• Qualified products lists, sources, or vendors; procurement procedures. • Warranty requirements.
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51 approaches to preserving and maintaining road signs once in service. Survey results for the budgeting method are shown in Figure 40.
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maintenance of sign, signal, and lighting supports was 8 of 39 agencies (21%) responding affirmatively.
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53 • Adjusting sign fabrication processes (e.g., to use higher quality materials)
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54 0 10 20 30 40 50 60 70 80 90 100 No Response Other Customer Surveys Customer Complaints Asset Value QUAL: Other QUAL: Vandalism QUAL: Dirt Accumulation QUAL: Corrosion QUAL: Structural Condition QUAL: Nighttime Legibility QUAL: Daytime Legibility QUAL: Color Fading QUAL: Retroreflectivity Performance or Health Index Conform to Current Standards Asset Age PHYS: Other PHYS: Vandalism PHYS: Dirt Accumulation PHYS: Corrosion PHYS: Structural Condition PHYS: Nighttime Legibility PHYS: Daytime Legibility PHYS: Color Fading PHYS: Retroreflectivity Percentage of Responses FIGURE 42 Measuring performance of road signs. PHYS = physical; QUAL = qualitative.
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55 signs. Vermont noted that its use of video is only to complement on-site inspections.
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Minimum Sign Retroreflectivity Standards The FHWA has devoted considerable attention to methods, materials, and guidelines to promote more effective performance of traffic signs. A major focus of attention has been the retroreflectivity of highway signs, an issue that has been a high priority for the FHWA since the 1980s.
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57 retroreflectivity levels provides a solid incentive and capability for agencies to prioritize sign replacement needs and allocate limited resources effectively. • The resulting better planning and programming of sign investment needs and the improved basis of resource allocation should contribute to greater safety and mobility of the road system to the benefit of the public.
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58 No Response Do Not Use Service Life Other Manufacturer's Data Professional Judgment Literature Agency Experience LCC Analyses Model Develop, MIS 0 20 40 60 80 100 Percentage of Responses FIGURE 45 Sources for determining service lives of sign components. MIS = management information systems; LCC = life-cycle cost.
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59 8 7 6 N o. o f R es po ns es 5 4 3 2 1 0 0 2 4 6 8 10 12 14 16 18 20 Estimated Service Life, Years FIGURE 46 Estimated service life of sign sheeting undifferentiated by reflective performance or color.
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6, the number of responses for estimated service life more than 4 to 6 years; and so forth. It should be noted again that the data in Table 13 and Figures 46 through 50 may be derived in part from the professional judgment of agency personnel.
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61 • Diamond grade sheeting Florida 7 years Saskatchewan 12 years The structural performance of sign supports has also been a topic of recent interest. Research has resulted in updated guidelines and specifications for structural supports (Standard Specifications for Structural Supports .
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levels for signs; and contributing to the public safety on the nation's road system. Determining Current Asset Status To apply the service-life concept in asset management a method is needed to determine where an asset is in its service life -- that is, how much life is consumed, and how much remains.
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Simple Program(s) for this Asset Broad-Based MMS, TIAMS, etc.
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– Utah DOT – Colorado DOT Region 5 – New Brunswick DOT – City of Cape Coral, Florida – City of Portland, Oregon. Two agencies mentioned partial implementations of sign management programs and databases.
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65 – To understand the benefit–cost and comparative service lives of different types of sign sheeting, such as high-intensity sheeting versus the new prismatic sheeting. – A related comment observed that new products emerge continually and it may be difficult to test service life of sheetings that will not have failed before new models become available.
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population, including older drivers (Ranney et al.
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