Adaptive Traffic Control Systems: Domestic and Foreign State of Practice (2010)

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23 INTRODUCTION The deployment of an ATCS can be a powerful tool, and it requires an agency’s commitment to staffing for operations and maintenance. ATCSs are often presented as a way to reduce labor required for repetitive development of signal timing plans. However, these systems cannot be considered hands- off types of systems. This chapter identifies institutional requirements for a successful deployment of an ATCS. In addition, the chapter reveals agencies’ perceptions on opera- tional problems with ATCSs. The final section of the chapter provides insight into the way agencies perceive maintenance of ATCSs. TRAINING It is critical that an ATCS agency acquire a level of knowl- edge that enables proper deployment, operations, and mainte- nance of the system. Without proper knowledge and technical expertise to operate an ATCS an agency can find itself in a hardware and software technology bind. If the agency does not have sufficient expertise, it needs to hire external consul- tants for any operational problems or the system will suffer. If there are no financial resources available to hire external consultants, or if the consultants are not readily available, the ATCS can go into a “hibernating mode”—it operates, but its performance will slowly degrade. In the long term, such hiber- nating systems may be left alone until they are replaced by con- ventional traffic signal control systems. Therefore, to acquire and retain the proper level of knowledge to operate ATCSs, agencies need to: • Receive proper initial training at the time when the ATCS is initially deployed, • Acquire continuous training and support to resolve oper- ational issues, and • Retain the expertise (personnel) during the life of ATCS operations. ATCS users stated that, on average, their vendors spent approximately 25 person-days to provide the initial training to enable the users to operate their system. However, this number varies considerably among ATCS users. Some of the users received only a few days of training, whereas others were receiving vendor support for the first 3 to 4 months. In the second instance, it did not mean that the vendors needed that much time to train their users, but primarily that they were available during this time for consultation without addi- tional cost (the costs of these services are usually included in the installation package). The estimated person-hours for the initial training might be taken with some reservation because some respondents could not provide an accurate estimate. Also, the level of initial training depends largely on users’ budgets for ATCS deployments and the size of their systems. In general, approximately 77% of ATCS users stated that they received adequate training. Of those who believe that the training was inadequate, 2% reported that the vendor/ consultant was not interested in providing the training. Another 2% reported that the training was too expensive and the costs were the major reason that the agency did not pur- sue the full training. The remaining 19% of the interviewed agencies reported that the training was inadequate for other reasons, which are mostly associated with the lack of interest on user side to pursue the training. Understanding the working principles of an ATCS is the major requirement to having an operationally successful ATCS. ATCS users do not find that the working principles of their ATCS are difficult. Some (18%) found that the working principles were difficult, but most of the ATCS users consider the principles to be easy. Figure 5 shows the detailed responses on the level of difficulty of ATCS working principles. These results provide a somewhat unbalanced picture of how understandable ATCS working principles really are. Most ATCS vendors do not provide comprehensive training to enable their users to fully utilize their ATCSs. They usually explain generic principles of each system in a highly aggre- gated way during the initial days of ATCS deployment. In addi- tion, users are usually given a level of training that supports only common every-day operations; customizing and opera- tional reconfiguration of the system are beyond their level of expertise. In this way, ATCS users are inclined to hire vendors and/or consultants for any challenging problems (e.g., addition of a new intersection or reconfiguration of the existing system of an intersection). From that perspective, ATCS users are usu- ally given an opportunity to perceive only the end user’s side of the system. The real difficulties in operating many of the available system’s bells and whistles are often not perceived by the users; hence, the bias reflected in the reported answers. Once the ATCSs are in place and initial validation of the systems is complete, approximately 62% of ATCS users rely CHAPTER FOUR INSTITUTIONAL ASPECTS

on their own (in-house) expertise. The others contract out to ATCS vendors either for all tasks (10%) or only for major mod- ifications in the operations of their ATCS (29%). It is inter- esting to note that ATCS users with larger ATCS deployments (50 or more intersections under an ATCS) are more inclined to use their own expertise (70%). Level of expertise on an ATCS that stays within an agency tends to increase with the size of the ATCS installation and the financial resources avail- able to keep that installation running. When it comes to building in-house expertise, 57% of inter- viewed agencies would like to acquire such expertise to fully utilize the potential of their ATCSs. It does not appear that these agencies would have problems securing funding for such additional training programs. Only 2% of the agencies believe that such an educational effort would be too expen- sive. Seven percent of the ATCS users believe that there is no interest within their agencies for such a training program. More specifically, 12% of the all interviewed agencies rec- ognize that such a lack of interest for full in-house expertise on the ATCS is associated with the concept that their ATCSs control only a small percentage of traffic signals under their jurisdiction. Therefore, the ATCSs do not attract enough atten- tion from their agencies to warrant the full in-house exper- tise. Another 24% of the respondents are unable to provide resources for such training because of insufficient funding. In general, the problem is not so much finding the resources for the training itself as in having enough individuals to attend the training and take responsibility for the full in-house expertise on the ATCS. 24 OPERATIONS The deployment of an ATCS can bring significant benefits to traffic performance on the network where it is installed and requires a commitment to staffing for operations and mainte- nance. ATCSs are often presented as a labor-saving alterna- tive to conventional traffic control, as the signal timing plans do not need to be developed on a regular basis. However, an ATCS is not a hands-off type of system. ATCSs are complex in operation, and it is believed that traffic engineers need at least four to six months to acquire a general understanding of these systems, whereas an experi- enced signal timing engineer needs about two months. These estimates indicate only the time needed to understand the system and not the time needed to become proficient. It may take years for a signal traffic engineer to acquire hands-on experience and become proficient with the system. For smaller agencies that run small-size ATCS deployments, retaining the ATCS-proficient staff becomes the most important ATCS- related issue. Approximately 56% of the surveyed ATCS users find that these systems are more demanding for operations than con- ventional traffic control systems. Nine percent of that 56% find ATCSs to be much more demanding than other sys- tems. Conversely, approximately 21% of ATCS users believe that ATCSs are less demanding. The remaining 23% per- ceive ATCSs as similar to their other systems. These answers are somewhat correlated with how the agencies operate and Very easy; 3; 7% Easy; 13; 30% OK; 20; 45% Difficult; 8; 18% FIGURE 5 Difficulty in understanding working principles of an ATCS.

25 maintain the systems. An agency with enough resources to hire outside consultants for the smallest operational tasks of an ATCS may find it easier to operate their ATCS because it is mostly operated (everything but every-day operations) by a consultant. Sixty percent of the interviewed agencies reported that they do not have enough staff to operate and maintain their ATCSs to the fullest potential. Many agencies reported that it is much easier to find funding for capital investments, such as an ATCS deployment, than for regular operations and maintenance of the existing technologies. A particular notion about ATCSs exists that implies that once they become oper- ational they do not need much maintenance. This might be one of the major reasons that some of the ATCS deployments are understaffed. The reality is quite opposite; ATCSs need more high-expertise maintenance than regular traffic control systems. If such a need is not recognized by the agency there is a considerable chance that the ATCS will underperform and eventually even be replaced by a conventional traffic sig- nal system. The respondents’ answers on their annual budgets for ATCS operations agree with the previous responses about the shortage of staff. About 63% of the interviewed agencies do not have an annual budget (for operations and maintenance of traffic signals) that is large enough to cover expenses for full utilization of their ATCSs. ATCS vendors and consultants need, on average, approx- imately 100 person-days to make an ATCS operational. How- ever, this number also varies considerably among agencies. Some of the systems required as few as ten days to become operational, whereas others required as much as an entire year. In general, most ATCS users (80%) were satisfied with the technical support from vendors and consultants. Reasons not to be satisfied were primarily related to the costs of the technical support (32%) and that some ATCS vendors do not provide local expertise to some of the ATCS users (34%). The other major complaints were that ATCS consultants have only a few hands-on experts (often only one) who cover an entire nation or that the vendors were reluctant to modify or improve the ATCS to better fit the user’s needs. Again, these problems can be associated with the number of ATCS users in the United States (or in the world). ATCS vendors and consultants do not find it profitable to train more than a few individuals on the ATCS or to customize software for a single user. If more agencies were to use ATCSs these prob- lems would be expected to diminish. Achievement of operational benefits from ATCSs is a major reason why these systems are installed. Outcomes of the following operational features are recognized as the most important benefits by ATCS users: • Responds well to emergency vehicle preemption and traffic congestion resulting from crashes, clears back- ups quickly. • Response to day-to-day and TOD fluctuations in demand. • If traffic demand is light the cycle was lower and more accommodating. • It does well when traffic flow is incremental, not when there are turbulent fluctuations in volume and demand. • Coordination between signals, handling special events, changes in traffic volumes and patterns, and tourist area traffic. • Ability to quickly respond to traffic fluctuations. • Covers special sequence operations. • Responds well to large volumes of traffic exiting on side streets that do not happen according to a regular sched- ule (e.g., a themed water park emptying as the result of a thunderstorm). • Provides detailed information of traffic signal from cen- tral office. • Maximizes throughput. • Network control is delivered effortlessly. On the other hand, the ATCS does not always perform as expected. There could be many reasons for this under- performance; at times, these systems are not fine-tuned and customized as needed. The literature review did not find any field evaluation studies that would show the benefits derived from the fine-tuning of an existing ATCS deploy- ment. There have been few studies where suboptimal deploy- ments of an ATCS are investigated (Taale et al. 1998; Jayakrishan et al. 2000); however, evaluations of customiz- ing well-operated systems are rarely documented. With so many operational parameters that can be adjusted in every- day ATCS operations one would need to explore, if not to optimize, the values of those parameters to achieve optimal ATCS operations. An ATCS sometimes does not perform as expected because initial expectations are set too high. When advertising an ATCS to potential customers, ATCS vendors at times over- state the abilities of these systems. This situation sometimes raises expectations concerning the ATCS, which in turn can lead to disappointment in their performance if the existing traffic problems cannot be solved (solely) by its deployment. Although the deployment of ATCSs can undoubtedly pro- vide an improvement to traffic flows under normal (under- saturated) traffic conditions, it need not be considered a cure for capacity constraints. If the expectations for the system are too high, there is a chance that the system will not be per- ceived as successful. This is especially true when observed from a single traveler’s perspective. The individual user’s benefits of an ATCS (or any other system) are generally lim- ited; however, when multiplied by the number of vehicles using the facility, they may bring significant savings to the motoring public. Surveyed ATCS users recognized the fol- lowing operational issues: • Poor operation for traffic demand surges such as those experienced during unplanned and planned special events.

• Synchronized phases sometimes get more green times than necessary, creating unnecessary delay on the other movements. • System takes 5 to 10 s to respond to calls on minor phases—does not have detector switching. • Single intersection falling off line. • Poor split flexibility. • System appears slower than expected when reacting to the variations of traffic flow and providing proper pro- gression on the corridor. • Construction activity—the detectors are either torn up, vehicles do not drive on them, or the lane is shut down and the detector senses that it is broken and goes into a “safe mode,” causing problems. • Pedestrian traffic—the system theoretically handles them well; however, our pedestrian volume is very high and pedestrian phases are needed during most cycles. • Because we compromised, a stage-type controller is used, which limits the ability of the operation to a dual- ring configuration; only 30% of the ATCS features are being used. • Not possible to identify a camera failure unless the inter- section is monitored all the time. • Data saving capacity—at present, data can be recalled only for the previous seven days. • Does not handle rush hour volumes well owing to pre- diction horizon being too close. • Emergency preemption and daily startup. • Detection and communication failures. • Handling oversaturated traffic conditions. • Locked traffic flows—especially at roundabouts. 26 Some of the operational features are listed for both because they were handled well and/or not handled well by ATCSs. This discrepancy in the reported observations can be attrib- uted to the knowledge that an ATCS of the same brand can function differently based on how it was set up and custom- ized. There are also inherent differences in how various ATCS brands handle certain operational conditions. From the list of not-handled-well features one can observe several problems that indicate poor fine-tuning or customization of ATCS parameters (e.g., delay on minor movements or ATCS per- formance on corridors under construction). These problems do not necessarily indicate that the initial set up of the ATCS was poor, but that the system was not modified further, when changes in operational conditions warranted such a modifi- cation. An agency needs to fully understand operations of its ATCS to recognize that the system needs modification, even if the modification itself is done by an outside consultant. MAINTENANCE ATCS users find that, in general, ATCS components are more demanding with regard to maintenance than the comparable components used by conventional traffic control systems. Fig- ure 6 shows how ATCS users perceive maintenance of major ATCS components (hardware, software, and communications). Sixteen percent of the ATCS users find that maintenance is much more demanding than with a regular system. Another 44% of respondents agreed that maintenance of ATCS is more demanding, but do not perceive such a large difference. Twenty-three percent found ATCSs to be similar to conven- Much more demanding than maintenance of regular traffic signals; 7; 16% More demanding than maintenance of regular traffic signals; 19; 44% Same as maintenance of regular traffic signals; 10; 23% Less demanding than maintenance of regular traffic signals; 5; 12% Much less demanding than maintenance of regular traffic signals; 2; 5% FIGURE 6 Level of difficulty of maintaining ATCSs.

27 tional traffic control in terms of the maintenance, whereas 17% believe that it is easier to maintain ATCSs than regular traffic signal systems. When it comes to which components of the systems are the most challenging to maintain, most of the ATCS users (65%) find that detection is the most chal- lenging. The second and third most difficult components to maintain were found to be communications (30%) and soft- ware and hardware (11% each). SUMMARY This chapter identified institutional aspects of operations, train- ing, and maintenance at the agencies that deploy ATCSs. ATCSs are only tools for traffic control, and as with any other tools could be supervised and controlled by a skilled engineering staff. Proper acquisition, training, and retention of expertise within an agency are the most important factors for alleviating institutional barriers for ATCS deployments. The current practice shows that at times an agencies’ ability to fully master ATCS operations is not sufficient. ATCS oper- ations are often not perceived as being difficult. However, it appears that there is a discrepancy between what ATCS users know and what they believe that they know about ATCS oper- ations. Some agencies reported operational problems that indicated a lack of the basic knowledge on how to operate an ATCS despite survey results to the contrary. Most ATCS users rely on in-house expertise, which is more an indication of the lack of resources available to hire outside support than that ATCS agencies have the required expertise. Most of the agen- cies would prefer to acquire more expertise on the ATCS, but inadequate funding is the major obstacle to acquiring the required knowledge. Inadequate funding does not indicate only problems in getting proper training; more importantly, it limits an agencies’ ability to hire more staff. Most of the ATCS users found that ATCSs are operationally more demand- ing than conventional traffic signal systems; however, over- all, an agencies’ ability to support these systems is less than to support conventional systems. The next chapter reports on system requirements for ATCS deployments.