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36 CHAPTER SIX IMPLEMENTATION COSTS AND BENEFITS INTRODUCTION tem expansion are too high, only 42% of all interviewed ATCS users agreed with this notion. Approximately 38% of Many factors influence the costs of an ATCS deployment and the respondents found the licensing costs for the expansion of achievement of the full ATCS benefits. This chapter identifies their systems to be affordable, whereas approximately 20% those factors that affect the costs of installing and operating either do not have to pay any licensing fees or did not need ATCSs. The chapter also addresses users' expectations and to expand the systems and do not know what the licensing achieved benefits from the ATCS deployments. The costs of expansion costs would be. ATCS deployments are captured through the costs of system installations per intersection and comparison of maintenance On average, the costs of installing an ATCS are approx- costs for ATCSs and non-ATCSs. In addition to discussing imately $65,000 per intersection. Figure 12 is a histogram the common evaluation studies to investigate the performance of ATCS installation costs per intersection. The histogram of ATCSs, this chapter reviews the benefits of various ATCS shows that these costs can vary significantly among various deployments. Finally, the chapter addresses public percep- ATCS users. The median and mode of the distribution (of tion on ATCS implementations and provides some examples ATCS installation costs per intersection) are approximately of lessons learned in practice during the implementation of $45,000 and $40,000, respectively. These numbers are signif- ATCSs. icantly higher than estimates reported previously in the litera- ture (Hicks and Carter 2000), where similar estimates were COSTS OF DEPLOYING ADAPTIVE between $20,000 and $25,000. It is important to note here that TRAFFIC CONTROL SYSTEMS the reported costs often include more than just the installation of the adaptive component of the system. Replacements of According to an earlier study (Hicks and Carter 2000), cost the local intersection hardware and software (sometimes appears to be a major obstacle to widespread ATCS deploy- even installation of new communication infrastructure) often ment. The term cost here encompasses both the capital and the accompany installation of the adaptive algorithms. In spite of operations and maintenance costs of an ATCS. There is some the survey's attempt to separate pure ATCS installation costs disagreement whether over the long term ATCSs are more from the infrastructure upgrade costs, which do not necessar- cost-effective than traditional signal systems because ATCS ily need to be conducted at the time of ATCS installation, the operations and maintenance costs are much lower than those ATCS users were able to report only the total costs (per inter- associated with signal re-timing. Others argue that the esti- section) of their system deployments. mates need not be simplified because an ATCS may have higher costs of physical maintenance such as the repair and Once an ATCS is installed there are costs to operate and replacement of detector loops. However, the answer, as always, maintain both the hardware and software of the system, as well lies somewhere in between. There are ATCSs that do not expe- as the infrastructure whose maintenance may be more costly rience higher detection maintenance costs than conventional owing to the higher infrastructure needs required by an ATCS traffic signal systems. Conversely, some ATCSs may have operation (e.g., more detectors or newer communications). significant signal timing adjustment costs. Belief that ATCSs The percentage of an agency's annual budget that is spent do not require any fine-tuning and that they can self-adjust on the physical maintenance of an ATCS is a good indica- their operations indefinitely is one of the biggest myths about tor of the cost-efficiency of maintaining these systems. To get these systems. an unbiased picture of the costs of ATCS maintenance we need to consider also the percentage of intersections that run A review of some recent ATCS deployments show that under an ATCS. Figure 13 shows the correlation between the licensing costs to run such a system may contribute an addi- two percentages. The figure indicates that, in general, propor- tional 10% to 15% to the overall installation costs. The licens- tions of annual budgets that are spent on maintaining an ATCS ing costs are usually not one-time costs because the licensing are lower than proportions of intersections under the ATCS in rights are sold separately for various intersection bundles. If the total number of intersections. The few outliers that were an agency wants to expand the system it will likely need to originally in the data set were removed to achieve a better co- purchase licensing rights for a larger intersection bundle. efficient of determination (R2). Removal of the outliers did Although there was a indication that licensing costs for sys- not change the overall relationship between X and Y data sets;