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19 signs served as the control sample and it was believed that In a different approach, one county planned to utilize con- if these signs were still meeting the minimum levels, then trol sign measurements to monitor failed signs and evaluate the newer signs should also be adequate. The estimated time visual nighttime inspectors. The county arranged to borrow requirement for a team to complete all measurements was a retroreflectometer from the state LTAP center with the pur- approximately 40 hours. The yearly retroreflective readings pose of collecting measurements of failed signs that were were analyzed to identify sign failures and failing contrast removed and replaced. The participant stated that the read- ratios. The new readings were compiled with the past mea- ings could help to identify if signs with high retroreflectivity surements to determine retroreflective deterioration rates levels were being removed prematurely or if sign inspectors for different sheeting types. In theory, control sign failures needed to remove certain signs sooner. In this case, the con- would identify the regional service life periods and all signs trol signs method was not only used to monitor sign retro with a similar installation age would be targeted for replace- reflectivity, but it was also implemented to help reevaluate ment. The county started using Type III sheeting in 1995 and improve existing maintenance practices. and switched to Type IV a few years ago. Sixteen years after installation, there had not been any measurements that were below the MUTCD minimum levels; therefore, there had not Sign Inventories been any targeted replacements. The new minimum sign retroreflectivity standards in the MUTCD do not require agencies to build and/or maintain The county was pleased with the control signs method and sign inventories. However, it was evident that many of the has presented material on the strategy in several conferences agencies contacted during this study believed that the new and meetings. The agency plans to continue the same control minimum sign retroreflectivity standards gave them the final signs procedures and they have expressed interest in purchas- justification they needed to build a sign inventory so that they ing a second retroreflectometer. As stated earlier, this was the could best manage their signs. only agency implementing control signs as the primary sign replacement method; however, there are several that have Sign inventories varied in functionality and complexity, used a similar strategy as a secondary or support method. but many were relatively simple and developed in-house. One of the simplest computer-based systems was developed Of the surveyed DOTs, 6 of the 16 state agencies pos- by a student intern as a summer project for one of the sur- sessed retroreflectometers. In 2007, one state completed a veyed agencies. The intern formatted an Excel spreadsheet sign service life study. This DOT collected retroreflectivity to include the desired sign attributes and it was found to and chromaticity measurements from 211 Type III control work well for a sign population of fewer than 1,000. Another signs in the field. The control signs were located in two dif- participant also used Excel and it worked satisfactorily for ferent parts of the state, and the sample varied in color and a much larger sign population. In a similar approach, one type. The results helped the agency to justify the extension agency created an Access database that interfaced with of the blanket replacement cycle from 14 to 18 years. The ArcView to manage both sign and spatial data. That sys- control sign measurements also determined that some of the tem was developed in 2001 by in-house staff and the system red STOP signs failed to meet some of the color require- included attributes, pictures, and GPS coordinates for more ments in ASTM Standard D4956-09. The agency believed it than 10,000 signs. One of the DOTs was operating a system had been being too conservative with blanket replacements that was developed in the 1980s by agency staff from a DOS and the control sign measurements helped it to ascertain a program. The system was a somewhat cumbersome and the more appropriate cycle length. In 2009, that DOT officially participant needed replacement; however, it still served a changed sign sheeting from Type III to Type IV and planned valuable purpose. on continuing control sign measurements to establish a suit- able cycle length for the new sheeting. Another county used an in-house system for tracking sign replacements and work orders that started as paper records. Another DOT using this method set up a control signs An employee took the paper record format and expanded it test deck to establish regional service life periods for exist- into a computer-based program. The program started with ing sheeting materials and to evaluate new products as they modest origins; however, it had evolved to include pull-down are introduced into the market. The control signs test deck menus, advanced data filters, and mapping capabilities. consisted of 56 signs that varied in color and material type. It was located in a protected maintenance yard office in the Nonprofit agencies and private businesses offer a wide state capital. The DOT positioned the signs to face south and range of software packages and products to manage sign tilted them at a 45 degree angle to accelerate the deteriora- inventories. In the nonprofit category, systems have been tion process. Retroreflectivity measurements were collected created by LTAP centers or university-based organizations. every six months and readings were compiled to analyze These programs are sometimes free or can be purchased at a sign deterioration rates. The control signs test deck helped reasonable cost. Two examples include Transportation Asset to establish an appropriate service life period for the DOT's Management Software from the Utah LTAP center and Road- expected sign life method. soft from the Center for Technology & Training at Michigan

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20 Tech University. Two of the surveyed agencies used one of ment one system that can encompass multiple roadway items the programs and both expressed positive opinions. Survey than to have multiple systems that manage one asset each. participants also used a variety of commercially available off- the-shelf systems, several of which were spoken of highly. One of the advantages to sign inventory is the ability to Essentially, the key was selecting a system that fits an agen- quickly access sign data. One participant reported that its sys- cy's requirements, which was easier said than done. tem was frequently used when there was an inquiry from a concerned resident. Staff could promptly access specific sign One participant acknowledged that finding existing soft- information and promptly address the issue. Another exam- ware packages was not difficult; however, it was determining ple involved missing signs; a technician in the field would which one best accommodates an agency's needs and desires report any missing signs to the main office. The office would that was. Another survey participant was evaluating differ- directly identify the missing sign and process the work order. ent programs at the time of this report and was preparing to In this way, the field technician would not be required to solicit vendors to present the system to the agency. Expected spend much time investigating and the replacement process sign life systems are long-term strategies, but a large part of could be accelerated. that investment comes at the beginning during the initial sign data collection process. The last example deals with knockdown signs. Before cre- ating a sign inventory, one agency made two separate trips Each agency has created its initial sign inventory and to handle such incidents. The first trip would ascertain the gathered the data differently. One DOT in the north started sign type, dimensions, and necessary hardware and the sec- the process during the winter when there was downtime. The ond trip was for the actual replacement or repair of the sign. staff reviewed roadway video-logging files and aerial images Having a sign inventory eliminates the first trip, because a at the beginning of the initial data collection. In the spring, technician can determine all of the sign information from an staff traveled the roadways to gather additional data and to office computer. Quickly accessing sign information is valu- confirm the accuracy of the initial collection. One surveyed able and particularly beneficial when time is an issue. county collected sign data and GPS coordinates for approxi- mately 24,000 signs during the summer. A team of one full- Agencies have also been incorporating new t echnologies time employee and one student intern absorbed the data into their sign inventories with the goal of streamlining main- collection tasks in with their regular summer maintenance tenance. Several of the surveyed DOTs were in the process of activities. The county engineer described the data collection transitioning their current systems to web-based platforms. process as manageable and indicated that the student intern Uploading large quantities of sign data has been time- was a significant help in the creation of the sign inventory. consuming and a new platform can significantly reduce the data processing time. One large city was expediting activi- A surveyed private consultant shared his experience with ties by implementing a paperless maintenance system; work inventorying sign data for nine U.S. military installations. orders would be received and completed digitally. Another One of the challenges for the consultant was estimating time agency was implementing a similar strategy, but with tab- demands and he determined that a team of two could collect let computers that maintenance technicians could use in the data for 220 signs each day. The consultant advised that an field. It is possible that in the future maintenance staff will agency should determine what sign attribute information is be able to receive work orders, query sign information, and needed before starting the collection process. He also recom- upload GPS coordinates with smartphones or other similar mended that it was easier to gather inessential sign data in devices from the side of the road. the initial collection than in a secondary effort. One partici- pant acknowledged that the data collection process helped Of all the advantages of the sign inventory, most of the to identify where additional signs were needed and where agencies touted the planning and management capabilities. unnecessary signs could be removed. Participants consistently noted the benefits of knowing the number of signs on the roadway for future planning, schedul- In addition to traffic signs, many of the participants inven- ing work orders, tracking replacements, and budgeting yearly toried and incorporated other roadway items into the same sign expenses. One DOT was able to budget sign replace- system. For example, one of the LTAP software packages ments three years in advance, allowing them to address any included modules to manage signs, culverts, guardrails, and funding concerns with DOT administrators. When switching roadway pavement conditions. Participants mentioned that from Type III to Type IV sheeting, one participant was able they also include pavement striping, roadway no-passing to quickly prioritize and budget Type III sign replacements. zones, and sidewalk data into the same system. One agency A city utilized sign data to estimate the cost of bringing its started with a program that was originally purchased to man- sign inventory into compliance for the 2015 and 2018 dead- age bridge information. Once the staff gained proficiency with lines. Similarly, a DOT was able to predict that the mini- administrating bridge data, the system was expanded to man- mum retroreflectivity requirements would cost an additional age other roadway items such as signs and culverts. Another $2.5 million per year to meet the 2015 deadline. In both participant recognized that it was more important to imple- cases, the agencies were better able to seek additional fund-

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21 ing sources because they provided detailed information and quickly create a support group that could address the techni- were able to express a clear need. cian's initial concerns. The support group also gathered tech- nician feedback to help customize the program and make it Despite the potential advantages of a sign inventory, more user-friendly. The agency brought in a vendor to pro- a system is only useful if the sign information is accurate. vide training and initial technical support. The technicians One individual remarked that the most difficult task of sign were able to gain a sense of ownership for the system when management activities was keeping the sign inventory up-to- they were involved from the onset of the project. The partici- date. Another DOT transitioning to a new and more advanced pant indicated that the sign inventory system was now a large system, reported a gap in time when sign information and part of the technicians' routine tasks and there have not been replacements could not be updated. This period of inactiv- any major concerns. ity resulted in some difficulties for maintenance staff and impeded the initial progress of the new system. Along with Based on the responses from this effort, it is clear that keeping the sign information current, it was also critical to there are many advantages of developing and using a sign keep staff proficient and trained. inventory system that go beyond simply managing sign retroreflectivity. Most agencies use their systems for the One of the participants shared experiences with a new potential planning and resource management capabilities. program and initial training. It was acknowledged that many One participant stressed that it took a great deal of time and of the maintenance technicians have limited experienced troubleshooting before benefits could be achieved, and that with computer programs. Many had concerns about the new other agencies considering this method should stay commit- system and believed that maintenance practices were fine ted, exercise patience, and continue to make incremental without adding further responsibilities. The solution was to improvements.