Practices to Manage Traffic Sign Retroreflectivity (2012)

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.

22 This chapter includes the case studies of four different agen- cies that participated in the survey. Each case study provides detailed information about the agencies’ sign replacement and management practices. These agencies have implemented effective combinations of methods and it was believed that providing additional detail to the readers could be beneficial. Each case study deals with different geographical and climatic conditions and the agencies were of different sizes and types. Clifton Park, new York Background The town of Clifton Park, New York, is in Saratoga County and is a small suburban community that lies just north of the Albany and Schenectady metropolitan areas. The town has about 37,000 residents and the municipal government main- tains approximately 200 miles of centerline roadway miles within a 50 square mile area. For the regional climate, average summer high temperatures are in the 80°F range and winter average lows are in the teens (25, 26). The annual cumula- tive snowfall is approximately 60 in. per year and the annual cumulative rainfall is about 38 in. At the time of this report, it was estimated that the town maintained approximately 6,000 traffic signs. Sign replacement Methods Clifton Park has been diligent with routine sign maintenance and day-to-day sign replacements, but the area has grown significantly within the last decade and the town has annexed many outlying residential developments, presenting some challenges for the small community. First, some signs and posts within the newly incorporated areas differ from the town’s standards, and it was necessary that the signs and equipment be uniform and compliant. The other main chal- lenge was the difficulty in budgeting and planning, because the town did not have an accurate estimate of the number of signs in existing and new areas. In 2007, the town began to address its signing issues and the MUTCD minimum retroreflectivity levels. Despite rou- tine maintenance, some of the signs did not meet the mini- mum requirements. The changes and sign replacement were viewed as an opportunity to improve overall quality; however, the revisions involved additional labor and expertise. The few Clifton Park staff members were proficient and knowledge- able about basic routine maintenance activities; however, minimum retroreflectivity requirements were a new issue. Minimum values contained in MUTCD Table 2A.3 were new and terms such as observation angle and contrast ratio had not been commonly used. To resolve this situation, the town sought outside assistance, by soliciting technical advice from regional experts. The Albany and Schenectady area contains many government agencies and Clifton Park staff was able to consult with professionals from the departments of trans- portation and public safety. After investigating the issues and consulting with regional experts, the town was able to obtain 402 safety improvement funding and set a course of action. When evaluating the different signing methods offered in the MUTCD, the town gravitated toward approaches that fit its resources and expertise. Measured retroreflectivity was not an option for a small agency such as theirs owing to the high price of a retroreflectometer and limited staff hours. Similarly, the visual nighttime inspection method was also deemed to be too time-consuming, and nighttime work would detract from important daytime activities. The town had expe- rience with GIS and GPS technologies and already possessed the necessary equipment. Therefore, the town opted to pursue a management approach where sign inventory and asset man- agement tools would be utilized. Staff first reviewed several different software products and packages. They found that several commercial systems offered too many features that would not be used. On the other hand, some of the LTAP programs were not equipped to handle all of the town’s needs. Ultimately, the town selected a local con- sulting company to help customize a computer-based system that would fit its needs. The consultants created a program that was similar to the town’s existing storm water management system. The program was designed to be very user-friendly with simple drop-down menus and buttons. Throughout the creation process, the consultants solicited advice and feedback from its intended users. Clifton Park planned to use the computer-based system to manage its sign data for a combined expected sign life and blanket replacement approach. The town was divided into 12 separate regions and signs would be replaced in one of the regions each year as part of a 12-year replacement cycle. The town was installing traffic signs with Type IV or higher sheet- ing materials. It was acknowledged that such sheeting may last chapter four CaSe StudieS

23 longer than 12 years; therefore, signs less than three years old in an area scheduled for blanket replacement would remain and be monitored periodically to ensure compliance. Signs between the installation age of four and five years would be removed, but would be used as temporary replacements if a sign was damaged or knocked down. Method review The town of Clifton Park acknowledged that many of the issues that small agencies encounter such as fiscal restraints and van- dalism were similar to challenges faced by larger agencies. One major difference that a small agency would have to contend with is the limited number of staff. This small agency needed personnel during daytime hours and experienced difficulties with rearranging work schedules. It was desirable to select a method that could easily be added to their already tight work schedules. Also, the staff at Clifton Park was informed about but not experienced with the minimum retroreflectivity require- ments. As a result, they sought outside assistance and advice from local professionals who were more knowledgeable. Ultimately, the town emphasized the importance of con- tinuing education and participation in professional societies. Through interacting and networking with other profession- als, the town was able to acquire additional funding, select an appropriate course of action, and customize a computer-based system that would address their current and future needs. By sharing knowledge and expertise, this small agency was able to address the problems presented by limited staff size and gain the benefits that a larger agency may possess. Town officials hope to share their experiences and knowledge with other small agencies at upcoming conferences. St. louiS CountY, MinneSota Background St. Louis County is a large rural county in northern Minnesota that covers approximately 7,000 square miles. The 2010 cen- sus population was approximately 200,000 residents and the largest city is Duluth. The area is accustomed to dealing with long winters and the average low temperature for the winter and spring is about 15°F (25, 26). Average annual precipita- tion is approximately 31 in. and the average annual snowfall is approximately 78 in. The yearly average possibility of sun- shine is 52% and the average number of cloudy days per year is 186. At the time of this report, the public works department employed seven full-time maintenance technicians who were engaged in traffic signing activities. The resident engineer esti- mated that the county maintains approximately 40,000 signs and approximately 3,000 centerline-miles. Sign replacement Methods The county was familiar with the MUTCD retroreflectivity requirements and took proactive steps to meet the compliance dates. The county had a combination of Type I, Type III, and Type IV sheeting materials. Based on their experience and field observations, most of the Type III and Type IV signs lasted from 10 to 12 years. The agency had been committed to regular sign replacement, but admitted that there were some Type I signs that had been on the roadway for 15 to 20 years. The first step the engineer took was to continue to use dura- ble and adequate sign sheeting materials. It was believed that some of the newer Type III and Type IV sheeting still per- formed adequately; however, the Type I and many of the older signs needed to be replaced. The engineer believed that replac- ing them with new Type XI signs would be more noticeable to for drivers during adverse weather conditions. St. Louis County previously implemented a blanket replace- ment method with adequate results. The county was divided up by townships and all signs on a segment of roadway were typically replaced at the end of the replacement cycle based on material warranty periods. The engineer simply modified and accelerated the existing blanket replacement schedules to meet both the 2015 and 2018 compliance dates. Along with this method, the county maintained a sign inventory system that helped with maintenance activities and resource management. The sign inventory started as an Access database that simply documented sign information and blanket replacements. By 2005, maintenance demands quickly exceeded the capabilities of this system and the agency transitioned to a new program. The engineer acknowledged that their needs and requirements continued to expand and the county changed programs again in 2010. The new system was relatively inexpensive and was able to track and manage other roadway items. Each sign inventory system transition progressed smoothly and there were no major issues or loss of information. The engineer reported that individual sign information was checked for accuracy during the course of each system change allowing the agency to identify missing and unnecessary signs. St. Louis County elected to continue blanket replacement because it was well-established and staff was accustomed to the routine replacement cycles. The visual nighttime inspec- tion method was considered; however, it was decided that the county was not properly staffed to inspect such a large amount of roadway. The measured retroreflectivity method was also quickly rejected for a similar reason. Method review One of the keys to St. Louis County’s approach was that the staff was familiar with the routine blanket replacement cycles and the sign inventory system. The primary and sec- ondary methods had worked effectively and the engineer did not need to implement any sizeable or hasty changes to meet the MUTCD compliance dates. Procedures were kept straightforward and consistent, which has allowed the county to be thorough in maintenance activities and not neglect any

24 areas. With the blanket replacement method, the engineer was not overly concerned about premature sign replace- ment and no signs were reused. It was acknowledged that being able to document sign compliance and follow a routine schedule were acceptable tradeoffs. Routine blanket replace- ments were staggered, which allowed the engineer to bet- ter plan budgets and work schedules. Overall, the county’s consistent and diligent approach has enabled it to maintain a high level of sign quality, which will allow them to easily meet the MUTCD requirements. Another key to the county’s approach was reducing the number of unnecessary signs. When St. Louis County changed sign inventory systems in 2010, it checked the accuracy and location of most of the roadway signs. During this period, the engineer made it a priority to remove any unnecessary signs. The county received guidance from the Minnesota DOT’s Traffic Sign Maintenance/Management Handbook (22), which reported that over-signing was a critical issue and a substantial drain on resources. The engineer stressed that signs should be installed when there was a clear need. Plans included removing special Warning signs that were deemed unnecessary, such as Deer Crossing symbol signs or Watch for Children signs. The engineer reasoned that the reduction in unnecessary signs could help drivers to focus on more critical driving tasks and allow the county to conserve valu- able resources. Phoenix, arizona Background Phoenix is the capital of Arizona and the sixth largest city in the United States. It encompasses 500 square miles and is comprised mostly of developed urban areas. The city’s nickname is the “Valley of the Sun” and it is well-deserved. High temperatures in the summer routinely reach 110°F and the annual possible sunshine rate is 85% (25, 26). Phoenix experiences an average annual precipitation rate of 8 in. and the average wind speed is 6 mph. At the time of this report, the city maintained an estimated 800,000 signs and 5,500 centerline-miles. Maintenance responsibilities were divided into six different regions and each region had its own sign crews who were responsible for daily maintenance and sign replacement. Sign replacement Method In Phoenix, the two issues that continuously affected the sign inventory were the harsh climate and urban vandalism. First, the constant sun and the high temperatures can cause some materials to deteriorate faster. Type III signs in some parts of the country may last from 10 to 15 years; however, Phoenix reported that its Type III signs remained adequate for only 8 to 10 years. The city recently changed to Type IV sign sheeting and hopes to extend the service life past 10 years; however, as yet they have not conducted any formal stud- ies on sign longevity. From its experience, red STOP signs and yellow–green fluorescent School Zone signs have a ten- dency to fade in color at a faster rate than other types of signs. Previously, the city requested that sign crews monitor these signs and replace any signs when the color appears to have faded. Legend peeling on Regulatory and Warning signs was another problem. To address these issues, the city switched from using black vinyl to acrylic materials, which has reduced the peeling and legend shrinking issues. Because of the harsh climate engineers continuously need to monitor sign quality and make small adjustments to extend service life. Concerning vandalism, there were high rates of spray paint-damaged signs in certain areas of the city. Phoenix has responded to this problem by applying anti-graffiti film to all signs. Maintenance staff can now wipe off or wash a sign to remove spray paint and not have to replace the entire sign. The engineers were concerned about maintaining adequate retroreflectivity levels; however, they have expressed more concern about other issues that affect sign appearance and message content such as color fading. The engineers previously used the blanket replacement method as its primary means for replacing signs. Blanket replacement cycles were based on the city’s experience with sign deterioration, because some materials would fail ear- lier than the specified in warranty periods. Because of the high vandalism rates and attrition, many of the signs on a given roadway that were scheduled for blanket replacement would differ in age. Maintenance staff would try to salvage and reuse adequate signs if they were one or two years old. Phoenix has acknowledged that it has been diligent in sign maintenance and management; however, there have been dif- ficulties with dealing with such a large urban area with a harsh climate. Despite proactive measures, many city signs would not meet the MUTCD minimum retroreflectivity require- ments. It was agreed that the city needed to take additional action if it was going to meet the 2015 and 2018 compliance dates. At the time, the city did not have a functioning sign inventory system, but it did have detailed records of blan- ket replacements in each of the six regions. Engineers used these records to prioritize sign replacements and complete a cost estimate. It was estimated that to bring street name signs alone up to compliance would cost $11.5 million. The engineers used the detailed cost information to secure stimulus money to fund blanket replacement of STOP and YIELD signs throughout the city. Additionally, they received a grant from a large sheeting manufacturing company to inventory and collect sign data for 14 major roadways. The initial inventory covered only approximately 250 centerline- miles of the total 5,500; however, it allowed the city to bet- ter manage resources on the more heavily traveled roadways. Using the aforementioned grant, the engineers planned to utilize an expected life sign approach and replace individual

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

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