Click for next page ( 26


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 25
25 signs. The engineers wanted to expand the initial data col- in the south. The yearly average possibility of sunshine for lection to cover more roadways, but funding was limited and four major cities within the state ranges from 56% to 61%. replacing inadequate signs was a higher priority. Until addi- The land type includes gently rolling hills, dense forest, and tional funding was secured, the city used expected sign life for agricultural flatland. The state has a mix of urban and rural the 14 roadways and blanket replacement for all other areas. areas and mirrors the demographics of many other states across the country. The Missouri DOT (MoDOT) roadway Other methods were considered, but none were determined system is comprised of approximately 32,000 centerline-miles, to be practical. It was also decided that purchasing a retro which include several major Interstates and a significant reflectometer was not feasible and borrowing one from an number of two-lane rural highways. It was estimated that the LTAP center not beneficial. Visual nighttime inspection was state maintains between 700,000 and 1 million signs. also considered, but staffing was an issue. Staff demands were already high with existing maintenance and overtime was a concern. If staff was going to conduct sign inspections, Sign Replacement Method the engineers preferred such inspections during routine daily MoDOT has been proactive with replacing signs resulting maintenance, because vandalism, sign discoloration, and from inadequate retroreflectivity. Rural areas experience more legend peeling were also major issues. vandalism and knockdowns were an issue in urban areas; how- ever, inadequate retroreflectivity was the primary reason for Method Review sign replacement. MoDOT engineers have been aware of the MUTCD requirements for some time and did not have any Overall, Phoenix has developed a viable plan and is working major concerns about the upcoming 2015 and 2018 compli- toward the goal of sign compliance despite the constraints ance dates. It believes that the overall sign population is in and challenges. The detailed blanket replacement records satisfactory condition and that existing methods for maintain- allow the city to evaluate the current state of the sign inven- ing and managing signs required only minor modifications. tory and helps them to prioritize sign replacements. Engi- neers have completed a detailed cost estimate that provides Prior to the minimum retroreflectivity ruling, MoDOT the total expenditures for bringing the sign population into used an alternating annual day/night inspection of its high- compliance for the 2015 and 2018 deadlines. With the cost way signs. These inspections were conducted by both engi- estimate, they were able to secure stimulus funding and neering staff and field crews. These individuals were not the previously mentioned grant. These additional funding officially trained, but simply learned by observing those they sources were limited, but they helped to address some of the inspected with. This process was somewhat effective, but did result in some variation in inspection results from one higher priorities, which were STOP and YIELD signs and part of the state to another. When the new retroreflectivity high-volume roadways. rules became official, MoDOT originally implemented a blanket replacement method as a means to address compli- When asked at the end of the survey to provide advice for ance. However, the department switched to visual nighttime other agencies, the engineers acknowledged that it was to inspections in late 2009/early 2010 because of the possible "start small and expand." Given the constraints and funding waste from early sign replacement that could occur and the limitations, the city was not able to complete a sign inventory desire to extend the sign service life of the signs as long as for all of the roadways or replace all of the signs at once. A possible. After 2010, nighttime inspections in the state were careful review of their resources and capabilities was under- conducted at least once per year and it was recommended that taken to create a detailed plan that prioritized short- and a team of two conduct inspections during the fall or spring. All long-term sign inventory management. Critical issues were inspectors followed the same basic procedures, but each of the addressed first and future expansion of the service life sys- 10 different districts in the state implemented slightly differ- tem planned for when resources became available. For a few ent inspection techniques. The participant responded that the roadways it was not ideal to implement an expected sign life primary concern with the current strategy was that inspections method and blanket replacement for other areas; however, it varied too greatly throughout the state and MoDOT needed a was practical and feasible at the time. more consistent approach. MoDOT first developed written guidelines for all districts Missouri Department of Transportation to follow. The guidelines standardized the visual nighttime Background inspection procedures and documented the basic steps. The second part of the guidelines provided descriptions for ade- The state of Missouri is situated in the middle of the coun- quate and failing signs. Because of the subjective nature of the try and experiences a wide range of climatic conditions. The inspection process, some districts were more likely to remove yearly temperature can vary from 90F in the summer to adequate signs prematurely. State engineers requested more below freezing in the winter (25, 26). The average annual consistent sign evaluations and sign performance descrip- snowfall ranges from 20 in. in the northern portion to 10 in. tions to help remove some of the variability. Along with the

OCR for page 25
26 guidelines, MoDOT implemented statewide training for sign ments if a sign has either passed or failed the visual nighttime inspectors. The training procedures were still being devel- inspection and ultimately offers a wide range of management oped, but it was envisioned that inspectors would view a capabilities to make maintenance operations more efficient. mix of adequate and failed signs to train their eyes. Quality It is believed that this is a well-rounded approach that ensures assurance checks were initiated to monitor the inspectors. An both high sign quality and effective use of resources. engineer would use a retroreflectometer to spot-check certain signs on randomly selected roadways. The quality assurance The state agency has proactively addressed the subjec- checks were a way to assess inspection consistency and to tive nature of visual inspections and implemented a program provide inspectors with feedback. to achieve more consistent sign evaluations. The guidelines and formal training help to refresh the knowledge of veteran To supplement the visual nighttime inspections, MoDOT inspectors and provides guidance to new staff members. created an advanced expected sign life system. The state pre- Quality assurance checks monitor the sign inspections and viously operated a program developed by a former employee; the results provide feedback to the inspectors. As a result, however, this system was now outdated and had become dif- MoDOT has created a cyclical process that continues to ficult to maintain. When this employee retired, there was a improve the quality and consistency of its sign inspection considerable loss of expertise and changes to the program method. were complicated. Also, the old system did not integrate well with new technology and a work order required several steps The new system offers a large number of management before it was included in the system. These complications and organizational capabilities. It helps track vandalism and negated many of the expected sign life system benefits and monitor sign quality to extend the life of valuable resources. changes were required. The engineers can use the planning, scheduling, and budget- ing tools to improve maintenance operations. Technicians in The new system offers the agency more i nterconnectivity the field are able to quickly access a considerable amount of and features that are more versatile. It was developed in- information to accelerate and simplify their tasks. The agency house and was a web-based Oracle product. It greatly reduces is enthusiastic about all of the new systems potential, but still unnecessary paperwork, and the web-based platform allows was most concerned with two very mundane issues; signs users to quickly search, upload, or change sign data. The tran- being knocked down by mowing crews and leaning posts. This sition from the old system to the new system was reasonably new sophisticated system by itself will not ensure that a sign straightforward and well-organized. The new system is com- is straight, but it will expedite and simplify the basic mainte- patible with touch-screen and smartphone devices, and it was nance needed to fix it. anticipated that technicians would be able to create or com- plete a work order in the field, which would then automati- This is an excellent example of an agency not concentrat- cally update the sign inventory information. The new system ing exclusively on retroreflectivity and neglecting routine helps to expedite maintenance operations and streamline the daily maintenance. A newly installed sign with high retro flow of data. reflectivity values does not necessarily ensure driver visibil- ity and comprehension. Routine daily maintenance can fix a Method Review twisted sign, right a leaning post, and trim trees limbs that would otherwise obscure a sign's message content. Focusing MoDOT has used both assessment and management methods just on retroreflectivity is not a substitute for daily mainte- to maintain its sign population. The visual nighttime inspec- nance and vice versa. Maintaining adequate retroreflectivity tion assesses sign retroreflectivity and confirms compliance and continuing daily sign maintenance are vital components with the MUTCD minimum levels. The new system docu- and there needs to be an appropriate balance of both.