FINAL DRAFT. Prepared for: Metropolitan Washington Council of Governments. May 29, 2002

Transcription

1 Satisfaction Through Superior Service Metropolitan Washington Region Traffic Signal Systems White Paper FINAL DRAFT Prepared for: Metropolitan Washington Council of Governments May 29, 2002 Trichord, Inc James Monroe Highway 303 East Glendale Avenue Leesburg, VA Suite 2 (703) Alexandria, VA

2 METROPOLITAN WASHINGTON REGION TRAFFIC SIGNAL SYSTEMS WHITE PAPER EXECUTIVE SUMMARY Final Draft May 29, INTRODUCTION BACKGROUND PURPOSE TRAFFIC SIGNAL OPERATIONS AND MAINTENANCE IN THE METROPOLITAN WASHINGTON REGION TRAFFIC SIGNAL OPERATIONS TRAFFIC SIGNAL MAINTENANCE SURVEY RESULTS: JURISDICTIONAL SIGNAL SYSTEMS PROGRAMS AGENCY COMMENTS ON SIGNAL SYSTEMS OPERATIONS AGENCY COMMENTS ON SIGNAL MAINTENANCE PROGRAMS OPPORTUNITIES FOR COLLABORATION/ IMPROVEMENT PLANS CONCLUSIONS...22 APPENDIX A: NARRATIVE SUMMARY OF AGENCY SURVEY RESULTS...24 GLOSSARY...34 Traffic Signal Operations White Paper Trichord, Inc.

3 EXECUTIVE SUMMARY Severe traffic demands are being placed on the major arterials in the Metropolitan Washington region no longer just during the typical weekday rush hour periods. Rather, these demands are occurring more frequently throughout the day, virtually every day. Many of these demands involve conflicting vehicular and pedestrian movements that require a high degree of traffic control to assign rights-of-way. When incorporated into a system that operates interdependently, traffic signals are one of the best tools for state and local traffic engineers to use in addressing these traffic demands and conflicts not only on corridors within particular jurisdictional boundaries, but throughout the Metropolitan Washington region. Traffic engineers and transportation professionals in the Metropolitan Washington region face a number of technical challenges and resource conflicts in their quest to optimize traffic flow and signal coordination. At a technical level, traffic engineers address issues in signal coordination, communications, and traffic control strategies. At a financial resources and staffing level, traffic engineers address management, operations, and maintenance issues. This traffic signal systems white paper summarizes the region s capabilities in traffic control, signal operations, and system maintenance. It presents the results of a regional survey of signal system capabilities, categorizes the signal system capabilities, and identifies system characteristics by geographic area. Throughout the Metropolitan Washington region, significant coordination of traffic signals occurs both within individual jurisdictions and between regional partners. There are currently several ongoing multi-jurisdictional traffic signal activities that promote regional objectives to improve traffic flow and safety in the region. These efforts, facilitated by the Metropolitan Washington Council of Governments (MWCOG), include the Pilot Arterial Corridor project, the regional traffic signal problem reporting system website, and the Traffic Signal Preemption/Priority study. From these activities, many regional partners have discovered unexpected similarities in their signal systems. Each jurisdiction is trying to optimize the use of technology to save money. Integrated Traffic Management Systems (ITMS) is the next technological phase for many transportation agencies around the country the Metropolitan Washington region is part of this evolution. The District of Columbia Department of Public Works currently has an ITMS initiative underway, which will integrate their arterial and freeway management operations (as well as some emergency services functions) into one center. It is envisioned that this effort will serve as a springboard for other agencies to begin considering the hard integration of functions and technologies to better serve their own needs, as well as the needs of the region. Likely candidates for future potential opportunities involve those agencies that have both signal systems and freeway management system operations, e.g., CHART and Montgomery County s ATMS, as well as VDOT s Northern Virginia District Smart Traffic Center and its Traffic Signal System. Traffic Signal Operations White Paper i Trichord, Inc.

4 All of the transportation agencies throughout the Metropolitan Washington region are taking tremendous advantage of the evolution of computer technology and using it to more efficiently and effectively operate and maintain their traffic signals and systems. Common areas of technology include the prevalent use of NEMA controllers and SYNCHRO optimization software, as well as system data archiving activities. The region is performing well under difficult circumstances. In the face of limited staffing and funding, transportation agencies staff continue to find creative ways to use technology to help save time and money, as well as to maximize their limited dollars and staff - especially in the area of signal maintenance. The region could perform better with additional resources. While all agencies are doing a great job with what they have, these transportation officials could do even more, if additional resources were made available, including: More staff, in order to be more proactive and responsive in systems operations and maintenance (for example, increased staffing levels would enable the agency to perform signal retiming and optimization on a routine basis, to keep up with the real world fluctuations of traffic demand and citizens complaints) Closed circuit television for remote system monitoring (to include verification and resolution of traffic and system problems before going out into the field; e.g. immediate adjusting of signal timings during an incident or identification of a signal bulb outage) Video detection Access to more communications infrastructure with greater bandwidth capabilities Greater event tracking capabilities within the systems (created in a database format to enable query of activities) Ability to observe signal operations in an off-line format Communication between the on-street master controllers Expanded master controller capabilities and functions Better traffic signal coordination capabilities, specifically on side streets Improvement of traffic responsive features to make procedures less cumbersome Ability to review preemption information from a central location Capability to work directly with optimization software from the system. While facing the everyday reality of limited staffing and funding resources, these agencies still manage to take a proactive approach to traffic management by utilizing a variety of tools to mitigate the effects of increasing vehicular, bicycle, and pedestrian demands on the limited capacity of transportation facilities in the region. Traffic Signal Operations White Paper ii Trichord, Inc.

5 Although the functional responsibilities and the technical complexity and size of each agency s systems vary, there is no doubt that each jurisdiction s system functionality is very important plays a vital role in meeting the transportation goals of the regional transportation network. These transportation agencies are operating and maintaining their systems to meet a demonstrated need locally, while at the same time, also providing a valuable service and benefit to the region. Traffic Signal Operations White Paper iii Trichord, Inc.

6 1.0 INTRODUCTION Severe traffic demands are being placed on the major arterials in the Metropolitan Washington region no longer just during the typical weekday rush hour periods. Rather, these demands are occurring more frequently throughout the day, virtually every day, and many of these demands involve conflicting vehicular and pedestrian movements that require a high degree of traffic control to assign rights-of-way. While there are various schools of thought on the need for traffic signals (and their advantages and disadvantages when installed), it has been shown that when a traffic signal is appropriately justified, properly designed, and effectively operated and maintained, it can be one of the best tools for state and local traffic engineers to use to address these traffic demands and conflicts. When incorporated into a system that operates interdependently, traffic signals can be one of a jurisdiction s most effective tools to assist in keeping traffic flowing in an efficient and safe manner not only on corridors within its own jurisdictional boundaries, but throughout a region. 1.1 Background In the 2000 The Region report (Vol. 39) published by the Metropolitan Washington Council of Governments, one of the main elements in Theme # 3 of the Key Themes of the Vision for the region is the need to put together a package of projects to fund. Within this element, projects were categorized into three (3) basic types: Fix-up, Enhancement, and Expansion. In the Fix-up category, the report stated that the region needs to invest more for fix-ups, such as sidewalk and traffic signal maintenance ; under the Enhancement category, the Council of Governments felt that investments in strategic improvements in areas such as traffic control would help the region get a lot more out of its existing transportation system. The implementation, operation, and maintenance of computerized traffic signals and systems is an example of one such strategic improvement being effectively used in the Metropolitan Washington region. Because of the numerous jurisdictions in the Washington metropolitan region and the invisible jurisdictional boundaries that the traveling public experiences on these major highway corridors, it is critical that a high level of communication, coordination, and cooperation take place among responsible transportation agencies in traffic matters. In the Metropolitan Washington region, experience has shown that state and local transportation officials have taken a strong and visible leadership role to ensure that this takes place. 1.2 Purpose The purpose of this paper is to document not only the technical aspects of the traffic signal system programs being operated and maintained around the Metropolitan Washington region, but also to highlight the creativity and successes of state and local transportation agencies in addressing the challenges and opportunities created by ever increasing traffic demands on limited capacity facilities especially in the face of limited staffing and funding. Traffic Signal Operations White Paper 1 Trichord, Inc.

7 2.0 TRAFFIC SIGNAL OPERATIONS AND MAINTENANCE IN THE METROPOLITAN WASHINGTON REGION Traffic signals in the Washington, D.C. region are either a state or local matter i.e., state and local transportation agencies are responsible for the justification, administration, installation, operations, and maintenance of traffic signals in their respective jurisdictional areas. These individual jurisdictions determine where, when, and how these signals are installed. Once these signals are installed, however, officials do not just walk away from the devices and let them work on their own. The operations and maintenance of traffic signals are dynamic, dayto-day traffic management functions of state and local agencies, performed not only during rush hour periods, but also during incidents (vehicular and non-vehicular) and special events. Many signals in the region operate without any relation to an adjacent jurisdiction s signal operation. However, as land use development continues to increase and to expand along major regional corridors (usually resulting in the need for more signals), the likelihood of signals needing to work interdependently also increases. 2.1 Traffic Signal Operations When operating a traffic signal system, the traffic engineer must consider a number of technical issues: signal coordination, communication methods, and control systems. Signal Coordination: When a corridor has several signals in close proximity, the traffic engineer may find it beneficial to consider coordinating these signals to improve traffic flow. Several factors must be reviewed when considering coordination, including (but not limited to): Traffic signal spacing Traffic volumes (vehicular and pedestrian) Turning movements Transit activity (loading and off-loading) Safety history On-street parking Traffic speed Land use While the above factors are of a physical, measurable nature, the traffic engineer must also take into consideration those factors that may be somewhat more difficult to measure, such as driver comfort and satisfaction. The expectation of the typical layperson driver is to experience as smooth a ride as possible along a corridor, with minimal to no delay or random stops. Figure 1 identifies which organization is responsible for signal coordination in different parts of the Metropolitan Washington Region. Traffic Signal Operations White Paper 2 Trichord, Inc.

8 Frederick County City of Frederick Montgomery County Virginia Department of Transportation Maryland State Highway Administration DC Department of Public Works Montgomery County Loudoun County Leesburg Rockville Local Jurisdictions Manassas Park Herndon Fairfax Manassas Vienna Prince William County Arlington County Falls Church Fairfax County Alexandria Washington, DC Prince Georges County Figure 1: Organizations Responsible for Signal Coordination in the Metropolitan Washington Region Communications/Interconnection Methods: Once the decision to coordinate has been made, there are two basic methods that traffic engineers can consider to achieve interconnection: through a wire-line or a wireless communications connection. Wire-line Connection. This method uses a physical wire connection to provide two-way communications between the controller assemblies in the field and/or back to a central control center. This direct connection can be achieved through various means the most commonly used for signal communications in the Metropolitan Washington region being copper wire, coaxial cable, fiber optic cable, and leased lines. Copper wire, also referred to as twisted pairs, is a widely used medium for interconnection of traffic signals. The copper cables are twisted in pairs in order to reduce electrical interference, or cross-talk interference due to signal ingress in one communication channel caused by signal egress from an adjacent channel. This medium is mainly used for signal data transfer and has limited capacity for use with video. Coaxial cable, initially used mainly by cable television service providers, has been found to have tremendous benefits to the transportation sector. Coaxial cable, also called coax, is a broadband communications technology that consists of a single inner conductor that has a Traffic Signal Operations White Paper 3 Trichord, Inc.

9 common axis with a second outer conductor (shield). This medium has the capacity of carrying many channels to transmit data, as well as video. Fiber Optic cable is rapidly increasing in use by transportation agencies, due to its tremendous bandwidth capacity (compared to copper and coaxial cable). It is considered analogous to a multi-coaxial cable, but is much smaller physically, has much greater capacity, can carry a signal over long distances, and is virtually immune to electromagnetic interference, because it transmits light pulses (rather than an electrical signal). Leased Lines are generally telephone-type twisted pairs or fiber optic cables that are leased by transportation agencies from a local communications company. A major drawback to using leased lines is the high on-going lease costs that are sometimes tied to the service provider s general service rate increases. Wireless Connection. While not commonly done with traffic signals, transportation agencies may also utilize wireless connections, such as radio or time-based coordination to achieve interconnection. Radio systems are a form of wireless communication connection and come in various forms, including cellular networks, satellite, and spread spectrum radio. While still not widely used for traffic signal operations, there are special circumstances where radio may be the best communications media to utilize. Examples of such circumstances include situations where there are no available landlines or when right of way is not available for communications infrastructure installation. There are disadvantages to radio, however, including line of sight requirements, fading issues, and limited bandwidth capacity. Time-based coordinators are also used to achieve communications between signals without cables. These time-based coordinators are basically accurate internal clocks that supervise a local controller unit by sync pulses and commands, similar to a master controller. Interconnection is achieved when several adjacent controllers are similarly equipped and operate from the same time reference point. The obvious drawback to this method is that two-way communication between controllers cannot be achieved, and the need for the clocks to be updated on a routine basis to ensure accuracy. Figure 2 identifies the communication methods used for traffic signal systems in different parts of the Metropolitan Washington Region. Traffic Signal Operations White Paper 4 Trichord, Inc.

10 Frederick County City of Frederick Montgomery County Agency-owned Copper Wire Combination of Agency-owned Copper and Fiber Leased Lines Loudoun County Leesburg Rockville Agency-owned Copper Wire, Fiber, and Leased Lines Manassas Park Herndon Fairfax Manassas Vienna Arlington County Falls Church Alexandria Fairfax County Washington, DC Prince Georges County Leased Fiber Combination of Owned Copper & Leased Lines Information Unavailable Prince William County Figure 2: Communication Methods Control Systems: There are several control systems available for signal system operation. Three types of control systems in operation in the Metropolitan Washington region include: (1) central control systems, (2) closed loop systems, and (3) hybrid systems. 1. Central control systems involve a computer control system in which the master computer, central communication facilities, console, keyboard, and display equipment are all situated at one location (e.g. a signal operations center). This approach can include the use of a master controller to control cycle lengths, offset and split for each cycle; or, a mutually coordinated system of intersections that does not require a master controller. Signal system staff coordinate and control traffic signals throughout a defined geographic area from the signal operations center. 2. Closed loop systems provide two-way field communication between the intersection signal controller and its master controller. The master controller then communicates information back to the signal operations center. 3. Hybrid systems are a combination of various control systems, strategies and technologies that a jurisdiction implements in a systematic fashion (e.g., time-based coordination, isolated intersections, etc.). Traffic Signal Operations White Paper 5 Trichord, Inc.

11 These computerized signal systems, with their communications links, provide great operations and maintenance benefits to transportation agencies staff. Personnel can use these systems to (remotely) monitor and adjust signals, as well as to respond more efficiently to incidents (e.g., adjusting signal timing in real-time during incidents and special events). Figure 3 identifies the types of control systems used in different parts of the Metropolitan Washington Region. Frederick County City of Frederick Central Montgomery County Closed Loop Hybrid Loudoun County Leesburg Rockville Unknown Manassas Park Herndon Fairfax Manassas Vienna Prince William County Arlington County Falls Church Fairfax County Alexandria Washington, DC Prince Georges County Figure 3: Control Systems 2.2 Traffic Signal Maintenance With all agencies experiencing increasing demands on their transportation infrastructure, as well as their staff, maintenance is a critical element in the success or failure of their signal system programs. There are several types of signal maintenance activities that a jurisdiction can undertake. The three main categories include: 1) repair maintenance (malfunction and breakdown), 2) preventive maintenance, and 3) response maintenance. 1) Repair Maintenance covers two basic areas: malfunction and breakdown. a. Malfunction: any event that impairs the operation without losing the display and sequencing of signal indications to approaching traffic. Malfunctions include Traffic Signal Operations White Paper 6 Trichord, Inc.

12 timing failures, detection failures (vehicle and pedestrian), loss of interconnected control, and other similar occurrences. b. Breakdown: any event that causes a loss of signal indication to any or all phases or traffic approaches. Breakdowns include controller unit failures, controller cabinet equipment failure, cable failures, loss of power, and signal lamp burnout, leaving no indication visible. 2) Preventive Maintenance: Checks and procedures to be performed at regularly scheduled intervals for the upkeep of traffic signal equipment. This includes inspection, cleaning, replacement, and record keeping. 3) Response Maintenance: Procedures and repairs made in the event of reported failed traffic signal equipment and its restoration to safe, normal operation. Benefits Of Maintenance Programs: Computerized systems and technology can reduce demands on limited agency manpower, and improved design of these systems can further assist an agency to offset system maintenance and related costs. Even with good system design, there are even more significant benefits that can be gained through a formal, properly funded and staffed maintenance program, regardless if an agency s system is high tech or not. On the other hand, if signal maintenance is not performed on these systems consistently, negative impacts can quickly result, including poor signal operations that can result in increased stops and delay, vehicular and pedestrian safety concerns, unstable traffic flow, congestion, increased emissions, etc. 2.3 Survey Results: Jurisdictional Signal Systems Programs Seventeen agencies throughout Maryland, Northern Virginia, and Washington, D.C. are responsible for the administration, implementation, operation, and/or maintenance of signal systems. These agencies were recently interviewed to gather technical information on their current signal system programs, as well as their thoughts and concerns on their systems effectiveness. Sixteen of these agencies with operations and maintenance responsibilities are listed in Tables 1-9, along with their systems attributes. Fairfax County, which allows the Virginia Department of Transportation (VDOT) to operate and maintain its signals, is not included in the table, but rather, is represented by VDOT. Detailed summaries for each agency s signal system program, can be found in Appendix A of this document. These summaries are based on the survey responses received from agency personnel. Traffic Signal Operations White Paper 7 Trichord, Inc.

13 System Type Operatiing System Communiicatiions Optiimiizatiion Software Controllllers Traffiic Siignall Management Support Software Other System Features Central Control Closed Loop Hybrid OS/2 or UNIX Win 95/98/NT Copper Fiber Priority Detection Own Lease Own Lease SYNCHRO Other NEMA 170 MONARC Other Fire, Rescue Transit Video Loop Microwave Infrared/Radar Archive Data DCDPW/DCDOT X X X NT X X X QuicNet X X MDSHA X X NT X X X X ARIES X X X X Montgomery County X UNIX NT X X X Custom X COMTRAC X X X Microwave Radar Prince Georges County X NT X X N/A N/A X Street-wise Virginia DOT X OS/2 NT X X X X X MIST X X Microwave X Arlington County X X OS/2 95, NT X SCOOT X X (SCOOT) Fairfax County X UW X X Infrared X X City of Alexandria Client server NT X X X TSP4 X X X X X X X City of Fairfax X OS/2 X X X X X X Radar X City of Falls Church Time-Based Coord.?? X?? X?? X X City of Frederick X N/A N/A X N/A N/A X N/A N/A X X X Town of Herndon UW NT N/A N/A N/A N/A UW X Peak X UW X Town of Leesburg X NT N/A N/A N/A N/A PASSER X PASSER UC X X City of Manassas X NT X X X VMS 330 X X X City of Manassas Park X X X N/A N/A X? X X X? City of Rockville X 98 X X X X Aries X X UW Town of Vienna X 98, NT X X X LM X LM X Key: N/A Not Applicable UW Underway? Information Not Available UC Under Contract 11/12/01 MWCOG TABLE 1: MWCOG Region Traffic Signal Systems - Signal System Features and Capabilities Traffic Signal Operations White Paper 8 Trichord, Inc.

14 Central Control Systems Closed Loop DCDPW/DOT MDSHA Virginia DOT Signal Optimization Software Hybrid Synchro Scoot Passer Other None City of Alexandria TSP4 Arlington Co. (UTCS) City of Fairfax (SIM Traffic) City of Falls Church N/A N/A N/A N/A N/A City of Frederick Town of Herndon UW N/A N/A N/A N/A N/A Town of Leesburg (NETSIM) City of Manassas (SIM Traffic) City of Manassas Park??????? Montgomery Co. Custom Prince Georges Co. City of Rockville Town of Vienna LM N/A Not Applicable UW Underway? Information Not Available Table 2: Control Systems and Optimization Software Traffic Signal Operations White Paper 9 Trichord, Inc.

15 Free Operation Fully- Actuated Semi- Actuated Flash Time-based Coordination Traffic Adaptive Traffic Responsive DCDPW/DOT MDSHA Virginia DOT Testing Testing City of Alexandria Arlington Co. City of Fairfax City of Falls Church City of Frederick Town of Herndon Town of Leesburg City of Manassas City of Manassas Park????????? Montgomery Co. Prince Georges Co. City of Rockville Town of Vienna Time of Day Pre-Timed N/A Not Applicable UW Underway? Information Not Available Table 3: Control Strategies Traffic Signal Operations White Paper 10 Trichord, Inc.

16 Controllers Communications Type 170 NEMA Copper* Fiber* Leased Lines DCDPW/DOT MDSHA Virginia DOT City of Alexandria Arlington Co. City of Fairfax City of Falls Church City of Frederick Radio Time-based Coordinators Town of Herndon N/A N/A N/A Future Town of Leesburg City of Manassas City of Manassas Park?????? Montgomery Co. Prince Georges Co. UW City of Rockville Town of Vienna N/A Not Applicable UW Underway? Information Not Available * - Agency Owned Table 4: Controllers and Communications Traffic Signal Operations White Paper 11 Trichord, Inc.

17 Monarc Mist Scoot Passer QuicNet Other DCDPW/DOT MDSHA Virginia DOT City of Alexandria Arlington Co. City of Fairfax ARIES City of Falls Church?????? City of Frederick N/A N/A N/A N/A N/A N/A Town of Herndon TCT-LM Town of Leesburg City of Manassas VMS 330 City of Manassas Park?????? Montgomery Co. COMTRAC Prince Georges Co. Streetwise City of Rockville Aries Town of Vienna LM N/A Not Applicable UW Underway? Information Not Available Table 5: Traffic Signal Management Software Traffic Signal Operations White Paper 12 Trichord, Inc.

18 Inductive Loops Video Microwave Magnetic Probes DCDPW/DOT MDSHA Virginia DOT City of Alexandria Radar Arlington Co. City of Fairfax City of Falls Church City of Frederick Town of Herndon UW Town of Leesburg City of Manassas City of Manassas Park?????? Montgomery Co. Prince Georges Co. Micro City of Rockville Infrared Town of Vienna N/A Not Applicable UW Underway? Information Not Available Table 6: Detection Traffic Signal Operations White Paper 13 Trichord, Inc.

19 Optical Push Button Audible GPS DCDPW/DOT (F&R, T) MDSHA (F&R, T) (F&R) Virginia DOT (F&R) (F&R) (F&R) City of Alexandria (F) Arlington Co. (F&R, T-U) (F&R) City of Fairfax City of Falls Church City of Frederick Town of Herndon Town of Leesburg (F) (F) (F) (F&R) UW City of Manassas (F&R, P) City of Manassas Park???? Montgomery Co. (F) (T) Prince Georges Co. City of Rockville Town of Vienna (F) Fairfax Co. (F&R) (F&R) F Fire R Rescue T Transit P Police N/A Not Applicable UW Underway? Information Not Available Table 7: Preempt / Priority Traffic Signal Operations White Paper 14 Trichord, Inc.

20 DCDPW/DOT WIN 3.1 WIN 95 WIN 98 WIN NT OS/2 UNIX VMS DOS MDSHA Virginia DOT City of Alexandria Arlington Co. City of Fairfax Future City of Falls Church???????? City of Frederick???????? Town of Herndon Town of Leesburg City of Manassas City of Manassas Park???????? Montgomery Co. Prince Georges Co. City of Rockville Town of Vienna N/A Not Applicable UW Underway? Information Not Available Table 8: Operating Systems Traffic Signal Operations White Paper 15 Trichord, Inc.

21 Data Archived? Database Schema Available? Oracle SQL DBase IV SyBase Other Yes No Yes No DCDPW/DOT MDSHA?? Virginia DOT City of Alexandria Arlington Co. City of Fairfax City of Falls Church????? City of Frederick Town of Herndon Town of Leesburg????? City of Manassas City of Manassas Park????????? Montgomery Co. Prince Georges Co. City of Rockville Access Town of Vienna N/A Not Applicable UW Underway? Information Not Available Table 9: System Databases Traffic Signal Operations White Paper 16 Trichord, Inc.

22 2.4 Agency Comments On Signal Systems Operations Overall, the majority of those agencies which have computerized systems have found that their systems are easy to operate and user friendly, resulting in their ability to do their jobs in a more proactive and efficient manner. Agency personnel feel that these systems and technologies enable them to quickly respond to citizens complaints and system problems. Staff engineers and technicians feel that these systems also make it easier to manipulate traffic data and to more rapidly create (or modify) timing plans. The ability to remotely perform this data collection, as well as the uploading and downloading of traffic signal timings to intersections, is a major plus to optimizing traffic flow. Collection and utilization of real-time traffic data offers significant benefits to the agencies, as they are able to gain more knowledge and a better, more realistic understanding of the traffic demands on their roadway systems. Staff from one Signals Operations Center indicated that their system has the capacity to provide comprehensive failure reports for communications and controller status, system and local flash operation, and status of system timing plans. This feature allows them to more accurately determine system problems and in turn, provide better and more expedient response maintenance. Others noted that they like the variety of features found in their systems, such as the closed-loop system operation, alternate phasing sequences, and transit priority control capabilities. These additional features allow them to be more creative in finding solutions to traffic problems, and also gives them the ability to assist a variety of transportation modes, such as transit, in providing better service to their customers. 2.5 Agency Comments On Signal Maintenance Programs Many agencies agree that having computerized systems help them tremendously in their maintenance activities, as they are able to more quickly respond to repair needs (due to increased accuracy in defining the problem). One agency noted that their maintenance costs have decreased significantly (95%) due to their ability to replace computers more quickly and at lower costs. Preventive Maintenance Programs: All of the agencies in the region with traffic signal responsibilities have some form of a Preventive Maintenance program, although they vary according to system size and sophistication, as well as maintenance staffing levels and schedules. Some agencies in the region have no set schedule for preventive maintenance work, while others have preventive maintenance work scheduled as frequently as every 90 days, others do the work every six months, and still others schedule preventive maintenance annually or every two years. Several agencies have defined schedules for certain pieces of equipment, such as signal heads being replaced every two years and going into controller cabinets to do preventive maintenance at least once a year. Still other agencies base their preventive maintenance schedules on field versus system devices. For some, the goal is to do preventive maintenance work on field devices annually, and system devices every two years. Traffic Signal Operations White Paper 17 Trichord, Inc.

23 Contract maintenance is used by those agencies with limited maintenance staff. One agency reported that while contract maintenance is conducted annually, their practice is that whenever a signal is upgraded, the contractor is directed to check out everything related to that signal and to repair anything needed at that time. Response Maintenance Programs: All area jurisdictions responded that they have response maintenance criteria to follow when dealing with repair calls. In response to the question of target times for repairing non-functioning traffic signals, the answers varied based on signal location and time of day. However, the general time range for response maintenance functions runs from immediately to 24 hours. With regard to geographic location, for one agency, the response times vary from three hours if the signal is in a downtown area, to five hours for those in residential areas. For those that have time-of-day criteria, most stated that their target time ranges from immediately and 15 minutes during business hours to longer after working hours. One agency stated that their response maintenance was immediately, if not sooner. The longest ever was two hours. Some agencies noted that they have staff on 24-hour call for signal maintenance and this helps them greatly in their efforts to be immediately responsive to traffic signal malfunctions or breakdowns. Signal Program Administration and System Constraints: Even with all of these technical advantages and benefits, most agencies find that some limitations still exist in their signal system programs. However, they recognize these as opportunities to creatively improve the systems in order to do their jobs even more efficiently and effectively. All agencies felt that additional staff support and funding would be extremely helpful, allowing them to operate their systems in such a manner that they could perform even more traffic management functions to assist in mitigating traffic congestion, unnecessary stops and delays. Having additional technology resources was also noted as something that would be beneficial. For example, some feel that video-based features (such as video detection and CCTV) would allow agency personnel to better monitor traffic conditions and remotely adjust/change signal timing, as needed. It is felt that this would be a more proactive and efficient way of addressing traffic signal problems, instead of having to rely on citizens complaints and/or radio traffic reports of malfunctioning signals. There are also issues with technology (controllers) becoming obsolete, resulting in poor vendor support and increased costs. Communications issues were noted by several agencies, from those who had no communications infrastructure in place at all (but need it), to those who felt their system s performance was hampered due to communications bandwidth limitations. Traffic Signal Operations White Paper 18 Trichord, Inc.

24 Custom features were also noted as potential trouble spots one agency noted that the process to create reports was cumbersome (due to a custom reporting feature), making the process time consuming. Desired Additional Program Administration and Signal System Features: While all agencies are doing a great job with what they have, these transportation officials could do even more, if additional resources were made available. Some of the features that agencies would like added to their programs and systems include: More staff, in order to be more proactive and responsive in systems operations and maintenance (for example, increased staffing levels would enable the agency to perform signal retiming and optimization on a routine basis to keep up with the real world fluctuations of traffic demand and citizens complaints) Closed circuit television for remote system monitoring (to include verification and resolution of traffic and system problems before going out into the field; e.g. immediate adjusting of signal timing during an incident or identification of a signal bulb outage) Video detection Access to more communications infrastructure with greater bandwidth capabilities Greater event tracking capabilities in the systems (created in a database format to enable query of activities) Ability to observe signal operations in an off-line format Communication between the on-street master controllers Expanded master controller capabilities and functions Better traffic signal coordination capabilities, specifically on side streets Improvement of traffic responsive features to make procedures less cumbersome Ability to review preemption information from a central location Capability to work directly with optimization software from the system. Although the functional responsibilities and the technical complexity and size of each agency s systems vary, there is no doubt that each jurisdiction s system functionality is very important and plays a vital role in achieving the transportation goals of the regional transportation network. These transportation agencies are operating and maintaining their systems to meet a demonstrated need locally, while at the same time, also providing a valuable service and benefit to the region. 3.0 OPPORTUNITIES FOR COLLABORATION/ IMPROVEMENT PLANS While there are significant benefits to providing and conducting good traffic operations and maintenance practices within a single jurisdiction, even greater gains can be achieved when State and local transportation agencies jointly pursue and initiate collaborative efforts in traffic Traffic Signal Operations White Paper 19 Trichord, Inc.

25 operations and maintenance across jurisdictional borders. Not only can these efforts maximize the effectiveness of an agency s limited resources, but they can also provide tremendous benefits to the traveling public such as smoother traffic flow, and reduced delays and stops along a corridor. Opportunities for cooperation between State and local transportation agencies can take the form of either technical or institutional collaboration, and can often be accomplished at very low (to no) cost to an agency. Examples of technical collaboration include activities such as: Signal coordination on an arterial corridor across jurisdictional borders Signal timing optimization along a corridor. For example, in order to move traffic smoothly along an arterial corridor that goes through more than one jurisdiction, traffic engineers in neighboring jurisdictions may decide to coordinate their traffic operations, e.g. use the same cycle length along the corridor. Institutional collaboration can be accomplished between agencies in many ways, including: Joint procurement and possible sharing of signal equipment Development, endorsement, and implementation of similar signal timing plans Sponsor and conduct joint training courses for staff, and Knowledge transfer among staff. An example of knowledge transfer could involve sharing the expertise of one agency s staff in a particular area. For example, many systems in the region utilize NEMA controller technology. If there is a state or local traffic engineer or signal technician who has considerable experience and expertise in the operations and maintenance of NEMA controllers, this knowledge and wisdom could be shared with other agencies that may have limited or no staff with knowledge or experience in this area. As another example, joint training courses could be arranged for regional participants. The work of MWCOG s Professional Capacity Building Working Group could be used to identify joint training needs and opportunities. The Metropolitan Washington region has already recognized the tremendous benefit of collaborative efforts in the area of traffic signals and systems. There are currently several ongoing multi-jurisdictional traffic signal activities that promote regional objectives to improve traffic flow and safety in the region. These efforts, facilitated by the Metropolitan Washington Council of Governments, include the Pilot Arterial Corridor project, the regional traffic signal problem reporting system website, and the Traffic Signal Preemption/Priority study. These efforts all serve as models of collaborative regional efforts in which an agency can participate with minimal disruption to its ongoing traffic signal system program. Another potential area of collaboration involves traffic data. The majority of agencies surveyed currently do some level of traffic data archiving, and the remaining agencies have plans to do so in the future. This data is a valuable resource, not only to traffic signal-related functions, but Traffic Signal Operations White Paper 20 Trichord, Inc.

26 also for regional transportation and land use planning activities and (as evidenced recently) in incident and evacuation activities. Being able to share this data with minimal, if any, need for database modifications would be of tremendous benefit to the region. Agencies could consider utilizing database programs that ease the sharing of data across jurisdictional lines. There are still other opportunities for collaboration worthy of review by area transportation and other governmental agencies. A major goal for the Metropolitan Washington region is to optimize traffic flow for all travelers. To that end, the majority of agencies surveyed have underway (or will in the near future) programs geared towards optimizing signal timings to improve traffic flow. This activity can yield tremendous bang for the buck, being one of the most cost-effective measures an agency can take using existing resources. While this optimization is geared towards improving traffic flow for all travelers, state and local agencies are also sensitive to the special traffic flow needs of their partners in the transit and emergency services communities, and are seeking safe and efficient ways to assist them in this area. For example, the Metropolitan Washington region is becoming more and more transit-dependent as single occupant vehicular (SOV) congestion continues to increase on the highway network. Transportation officials feel that transit is a valuable alternative for travelers to consider to help address this congestion problem, and recognize that providing reliable, high quality and expedient transit service is a must to lure these travelers out of private automobiles. With this in mind, traffic engineers throughout the region are exploring incorporating transitrelated features into their (current and future) signal systems. This includes utilizing system hardware, software and/or communications features that can be easily adapted to assist in the functionality of a current and future transit signal priority system and/or AVL transit fleet activities. These types of signal design considerations can also be applicable to any effort involving the safe and efficient routing of emergency response vehicles, such as fire and rescue units, as well as police. Many jurisdictions already have some basic level of preemption infrastructure in place for these emergency responders. It is most likely that, as the public safety need increases and the technology matures, these systems will also become a part of traffic signal system operations. By considering transit and emergency services needs in the design, upgrade and operations phases of signal systems, transportation agencies will be ensuring that technologies, systems, and organizations work together in a safe and cost-effective manner to accomplish the individual jurisdictions goals, as well as the region s goals. Integrated Traffic Management Systems (ITMS) is the next technological phase for many transportation agencies around the country and the Metropolitan Washington region is part of this evolution. The District of Columbia Department of Public Works currently has an ITMS initiative underway, which will integrate their arterial and freeway management operations (as well as some emergency services functions) into one center. Traffic Signal Operations White Paper 21 Trichord, Inc.

27 Likely candidates for future potential opportunities involve those agencies that have both signal systems and freeway management system operations, e.g., CHART and Montgomery County s ATMS, as well as VDOT s Northern Virginia District Smart Traffic Center and its Traffic Signal System. 4.0 CONCLUSIONS All of the transportation agencies throughout the Metropolitan Washington region are taking tremendous advantage of the evolution of computer technology and using it to more efficiently and effectively operate and maintain their traffic signals and systems. In addition to this observation, several other conclusions were drawn based on the survey data. Throughout the Metropolitan Washington region, significant coordination of traffic signals occurs, both within individual jurisdictions and between regional partners. There are currently several ongoing multi-jurisdictional traffic signal activities that promote regional objectives to improve traffic flow and safety in the region. These efforts, facilitated by the Metropolitan Washington Council of Governments (MWCOG), include the Pilot Arterial Corridor project, the regional traffic signal problem reporting system website, and the Traffic Signal Preemption/Priority study. From these activities, many regional partners have discovered unexpected similarities in their signal systems. Each jurisdiction is trying to optimize the use of technology to save money. Integrated Traffic Management Systems (ITMS) is the next technological phase for many transportation agencies around the country and the Metropolitan Washington region is a part of this evolution. The District of Columbia Department of Public Works currently has an ITMS initiative underway which will integrate their arterial and freeway management operations into one center (as well as some emergency services functions). All of the transportation agencies throughout the Metropolitan Washington region are taking tremendous advantage of the evolution of computer technology and using it to more efficiently and effectively operate and maintain their traffic signals and systems. Common applications of technology include the use of NEMA and Type 170 controllers and SYNCHRO optimization software, as well as system data archiving activities. The region is performing well under difficult circumstances. In the face of limited staffing and funding, transportation agencies staff continues to find creative ways to use technology to help save time and money, as well as to maximize their limited dollars and staff - especially in the area of signal maintenance. The region could perform better with additional resources. While all agencies are doing a great job with what they have, these transportation officials could do even more, if additional resources were made available, including: More staff, in order to be more proactive and responsive in systems operations and maintenance (for example, increased staffing levels would enable the agency to perform Traffic Signal Operations White Paper 22 Trichord, Inc.

28 signal retiming and optimization on a routine basis to keep up with the real world fluctuations of traffic demand and citizens complaints) Closed circuit television for remote system monitoring (to include verification and resolution of traffic and system problems before going out into the field; e.g. immediate adjusting of signal timings during an incident or identification of a signal bulb outage) Video detection Access to more communications infrastructure with greater bandwidth capabilities Greater event tracking capabilities in the systems (created in a database format to enable query of activities) Ability to observe signal operations in an off-line format Communication between the on-street master controllers Expanded master controller capabilities and functions Better traffic signal coordination capabilities, specifically on side streets Improvement of traffic responsive features to make procedures less cumbersome Ability to review preemption information from a central location Capability to work directly with optimization software from the system. While facing the everyday reality of limited staffing and funding resources, these agencies still manage to take a proactive approach to traffic management by utilizing a variety of tools to mitigate the effects of increasing vehicular, bicycle, and pedestrian demands on the limited capacity transportation facilities in the region. Although the functional responsibilities and the technical complexity and size of each agency s systems vary, there is no doubt that each jurisdiction s system functionality is very important and offers a valuable service to the transportation goals of the regional transportation network. These transportation agencies are operating and maintaining their systems to meet a demonstrated need locally, while at the same time, also providing a valuable service and benefit to the region. Traffic signals are an everyday occurrence for many travelers in the Metropolitan Washington region; therefore, it is of the utmost importance that traffic engineers and signal technicians make every effort to ensure that these devices are being operated and maintained to the highest possible degree of safety and efficiency. Traffic Signal Operations White Paper 23 Trichord, Inc.

29 APPENDIX A: NARRATIVE SUMMARY OF AGENCY SURVEY RESULTS DISTRICT OF COLUMBIA DEPARTMENT OF PUBLIC WORKS/DOT The Washington, DC Signal Operations Center (SOC) is located in the Public Works Department. There are 25 staff-persons who operate and maintain the central control system (10 field technicians, five office personnel and 10 consultants who are engineers and technicians). The system includes 1,500 traffic signals that function in fully-actuated, time-based coordination and/or pre-timed mode. It is estimated that five to ten traffic signals are added to the system each year. Type 170E controllers are currently used, but the agency is transitioning to 2070E. There are 500 inductive loops, three video detection and 100 microwave detection devices. Fifty percent of system detection is on-line using agency-owned copper lines. (The plan is to go to all fiber in the future). QuicNet 4.0 is the software application that is used to support the management of the traffic signal system. The agency uses a Windows NT operating system, with a LAN network and TCP/IP protocol. An SQL database archives system data but a copy of the agency s database schema is not available. The hardware used to operate the system includes six IBM Netfiniti servers with ten operator interfaces, using 256M of RAM with a hard disk size of 30GB. The central processing units (CPU) operate at a speed of 500 MHz. The system provides remote dialin capabilities using landlines. Currently, the District has plans to do a complete system upgrade. A priority control system for Fire and Rescue, as well as police operations, is in place (42 optical units); fire and EMS personnel have access to these devices. There are three vehicles with AVL/GPS capabilities. There are 40 Opticom units installed for transit priority, mostly along Georgia Avenue (no GPS capabilities). There are twelve closed circuit television (CCTV) cameras currently in operation, with plans to install three hundred more cameras in the future. MARYLAND STATE HIGHWAY ADMINISTRATION The Signal Operations Center (SOC) and the Statewide Operations Center are located at the Office of Traffic Safety, in Hanover, Maryland. The Signal Operations Section contains approximately 40 field technicians who operate and maintain the SHA's network of traffic signals and traffic signal systems. This network includes approximately 1500 traffic signals operating in either "free" (fully actuated) mode, time-based coordination, or as part of a closed loop system. Approximately 50 new traffic signals are added to the system each year, using NEMA controllers. The closed loop systems contain approximately 1000 inductive "sampling loops" used for system data collection. The agency s operating system is DOS, Windows 3.1 and Windows NT, with an Oracle database (system data is archived). The network is Netware and Windows NT-based, using IPX and TCP/IP protocols. There are approximately four operator interfaces. SYNCHRO is the software application used for optimization. The system has remote dial-in capabilities utilizing agencyowned fiber and copper lines, as well as cellular communication. Traffic Signal Operations White Paper 24 Trichord, Inc.