Traffic Signal Management Plans

Chapter 3. How to create the Traffic Signal Management Plan

Involve the Appropriate Stakeholders or Staff

The most appropriate staff to have input to the development of a traffic signal management plan (TSMP) will vary depending on the size of the organization and the manner in which its activities are structured. Typically staff with responsibility for the design, operations, or maintenance of the traffic signal system will be involved in developing the TSMP. This may include the following:

• Agency traffic engineer.
• Traffic operations engineer.
• TMC manager.
• Traffic signal timing supervisor.
• Lead technician.
• Maintenance supervisor.
• Signal designers.
• Transportation planners.

The champion of the TSMP should be the senior person responsible for successful operation of the traffic signal system. This person has an interest in the performance of the traffic system as it is impacted by traffic signal timing, an interest in the standard of maintenance, and an interest in good signal design, modification or replacement at an appropriate time.

The champion within the agency may be supported by internal staff and/or by a qualified consultant with experience in strategic planning, operations, maintenance and/or systems engineering in order to develop the document.

Scale and Scope of the Document

Deciding on the appropriate scale of the activity and scope of the document will depend on its intended use and on the current state of your signal program. Research suggests that in the majority of agencies, operations capability tends to be immature (largely relying on individuals using ad hoc procedures to time signals), while design and maintenance tend to be more advanced (with more formalized procedures and checklists). Overall the design, operation, and maintenance activities often occur in silos, with the result that needs, resources, and capabilities often do not align satisfactorily. An agency with many ad hoc processes might initially use the TSMP to develop, or identify the need for, documented processes.

If an agency currently operates on a largely ad hoc basis that is intended to initially concentrate on formalizing the planning, execution, and performance measurement of maintenance activities, the initial plan can be relatively small. However, if an agency is well organized and the purpose of the plan is largely to formalize current practices and to facilitate and provide a training and succession plan that will continue successful operation beyond the tenure of existing staff, then it is likely that all sections will be required. For succession planning in an agency with well documented processes, the TSMP might document connections of regional and agency goals to traffic signal program objectives.

Within a State agency, it may be appropriate to have a statewide TSMP, or a separate one for each district. In a smaller agency in which signal timing is handled by the maintenance organization, then the senior technician may be the most appropriate "owner" of the TSMP.

Based on experience with several test groups, development of the TSMP typically requires one or two half-day meetings to develop a consensus on the issues, goals, and objectives, followed by several months of activity by a staff member(s) and/or consultant. These case studies have also shown that an agency should set its expectations for the TSMP at a realistic level that initially represents an improvement over its current situation, and not try to develop a fully comprehensive TSMP at the outset. The starting point should begin at the existing level of capability, so that plans and processes move gradually from ad hoc to documented, documented to measured, and measured to optimized.

Support is also available from FHWA’s Resource Center. Staff can provide resource materials, such as an annotated outline for a TSMP, can review draft TSMP's and provide content advice, and may also be able to facilitate training workshops for groups that are sufficiently large. Useful materials may also be found on FHWA’s website at: https://www.fhwa.dot.gov/resourcecenter/teams/operations/

Obtain Appropriate Levels of Approval

A TSMP should be approved and/or endorsed by the chief executive of an agency. This ensures the support of decision-makers and budget approvers for the activities covered by the TSMP. It also ensures that those activities will be consistent with the plans and programs of other units of the agency.

Approach

There are two different but completely acceptable approaches to developing a TSMP, illustrated in Figure 6. The classic planner approach is top down, which involves progressively developing the GOST statements, starting with goals, which are informed by the agency’s vision and policy, and working down to tactics. Within agencies that do not have well-documented processes, it is likely that a top-down approach will be necessary to formulate objectives, strategies and tactics that are consistent with agency goals. The second approach, often more understandable to traffic signal operators, is bottom up. It involves describing the strategies and day-to-day tactics that are used and then describing in turn the objectives that are being achieved by using those tactics and mapping them to the agency goals that are satisfied by those objectives.

Figure 6. Planner and operator approaches to traffic signal management planning.
Source: DKS

Often, the most difficult part of the process is to elicit objectives that are stated in a way that is meaningful to traffic signal management, yet clearly consistent with the agency’s overall goals and transportation objectives. You must be careful to avoid stating objectives for which the performance measures are not associated with traffic signal management or operation.

For example, an agency's objective related to bicycle safety and mobility may be to "…provide safe and efficient bicycle facilities to and from all major activity generators." However, this could be addressed through many avenues that do not specifically involve traffic signals, such as bike paths, exclusive bike lanes on arterials or parallel roads, shared facilities away from arterials, as well as specific treatments for bicycles at traffic signals. A more focused objective suitable for traffic signal management could be to "…safely and efficiently accommodate all bicycles at all traffic signals." This could lead to specific strategies to be applied at traffic signals (such as detecting bicycles and providing appropriate safety timing when bikes are present) and specific metrics that will determine the extent to which that specific objective is being met through traffic signal management.

Both approaches may be necessary for the assembly of a TSMP. It is easiest for practitioners to start from the bottom by documenting the day-to-day activities (tactics) and work up to the strategies and objectives. It helps to put context around what an agency does. Then go to the top and find the goals and objectives of the agency and work down to the strategies.

The hardest part of this process tends to be developing clear and concise objectives that are actionable and measurable. An agency's planning documents often have statements about vision, goals, objectives, guiding principles and policies that begin at a lofty level and the action plans developed in those documents often sound like statements of objectives to traffic signal operators. An agency should expect that the objectives it creates based on current strategies and activities will likely not match the level of the objectives statements often found in planning documents, as illustrated in Figure 7.

Figure 7. Diagram. Planner vs. operator goals, context, objectives, strategies, and tactics (GOST) perspective.
Source: DKS

At some point the objectives will be consolidated into those relevant to the traffic signal system and then the strategies need to be reviewed. Working both from the bottom up and the top down helps to identify if there are any holes in the strategies and tactics. You will able to identify if there are goals not being supported by strategies or if there are activities that don’t support the goals and objectives, as illustrated in Figure 7.

The following steps provide an outline of the process that may be used to create and adopt a TSMP. The actual process you use should be tailored to suit the size of your organization, the extent to which other agencies will participate in the development process and eventual implementation of the plan, and the key people who are championing the plan. A very important early step is to set out the proposed process and have as many stakeholders as possible commit to following the process before you embark on it.

Process

The intent of the TSMP is to align the activities that are being done to operate and maintain the traffic signal system with objectives and the overarching goals of your agency. As shown in Figure 7, instead of starting with the goals and objectives and working down to the strategies and tactics, the process begins by documenting the activities currently performed by the traffic signal staff (step 1) in each area of the traffic signal program (maintenance, design, operations and management and administration. These activities represent tactics, and it is often easiest to begin by documenting maintenance activities, followed by design and then operations, management, and administration. The process then work its way up to strategies by requiring planners first to ask themselves why each activity is performed (step 2a), then to create an initial set of objectives that could be supported by those strategies. Rather than developing goals at this point, these will be extracted from existing sources (step 3a and 3b).

The initial strategies will be revised (step 5) and expressed in a way that clearly supports the objectives. This may also involve revising the tactics to add new tactics to fill apparent gaps or removing tactics that (while perhaps being of some use) are not necessarily supporting any defined strategy. Some iteration may be necessary between steps 2, 4 and 5. In step 6, evaluation methods and strategies will be selected, and the full TSMP will then be compiled (step 7).

Figure 8 depicts a flow chart of the process. As can be seen, the operator approach and planner approach run parallel to each other.

Figure 8. Diagram. Traffic signal management plan development flow chart.
Source: DKS

Step 1 – Document Activities

Step 1 starts with the operator in mind and begins with the tactics. Write down the activities that staff currently do related to the maintenance, design or operation of the traffic signal system. The list of activities should include any activity performed on some recurring basis. An activity could occur annually, be a daily function, or be something that is only done when a specific event or situation occurs. This list will result in your system strategies and tactics. Use this as the basis for a brainstorming session in order to identify all activities. It is also critical to list activities that are contracted out. This list can also include a reference to existing policy documents and procedures you follow (maintenance checklist, signal timings guidelines, etc.), instead of repeating the detailed tasks within each procedure.

It may be helpful to group the activities into three groups: maintenance, operations, and design. By doing this, the staff involved in each of the categories can provide input on their specialty. There may be overlap between the different groups—this is okay. The duplications will be condensed later. The list will most likely contain a mixture of strategies and tactics—this is okay also. Tactics are "what" you do and strategies are "how" you do it, and at times it is difficult to draw the line between them.

The following questions are meant to help you document your activities, by organizing them around the typical categories associated with traffic signal system management. The questions are not all encompassing and your agency may do things not listed here. You can also review job descriptions for your staff to ensure all activities are captured.

Traffic Signal Maintenance

Preventive Maintenance

• Do you perform preventive maintenance of traffic signal hardware? What is included in maintenance list?
• How do you keep track of the condition of signal equipment?
• Do you provide locate services for underground conduit/wire associated with signal system?
• Do you maintain other agency's signal hardware? Do they have preventive maintenance guidelines different than yours?

Routine Maintenance

• How do you know when a detector is not working? (citizen call, central system alarm, routine maintenance).
• Do you maintain log of maintenance issues?
• How do you verify communications is operating as it should?
• What do you do in case of damaged vehicle detectors? (adjust timing, coordinate with signal operator, fix loop)

Emergency Maintenance

• What are your emergency maintenance procedures?
• What do you do in case of traffic signal power outage? (stop signs, generator)

Operations

System Efficiency

• How do you keep track of the signal timings/phasing at each intersection?
• When do timings need to be updated? (What are the triggers? Time, land use developments, etc.)
• Are you measuring performance? What kind?
• Who updates the signal timing? Agency staff or consultant staff?
• How do you monitor the signal operations? (Remote or in field)
• How do you quantify success?
• Do you modify signal operations during construction?

Intersection Efficiency

• How do you determine (calculate) local signal timings? Do you have a standard? Do you review timing routinely?
  • Minimum green, Maximum green
  • Walk, Flashing Don't Walk
  • Yellow, Red
  • Detector settings
• Do you review split logs for phase failures? What do you do about it?

Coordination

• What are your intended outcomes from signal timing? For example, to maximize throughput during peak hours, provide smooth flow during business hours, equitably distribute green time during off-peak times?
• How do you decide when to coordinate signals? (What factors do you consider?)
• How do you develop coordinated timings? Do you have documented policy or guidelines for selecting the following or other parameters?
  • Cycle length
  • Split
  • Offset
  • Advanced features
• How do you determine coordination timing patterns?
• What software program do you use to develop coordinated timings?
• Do you use the results of software analysis directly, or modify the software results to accommodate your objectives that are not adequately reflected in the software models?
• What do you do when traffic conditions are oversaturated, heavy or light? (briefly discuss general operations strategies in each case)
• Do you program special event timings?
• How do you prevent or accommodate queue overflow through use of signal timings?
• How do you coordinate during congestion?
• How do you accommodate various land uses in your coordination timings?
• Do you use a different philosophy to time signals on a corridor with transit?
• Do you time signals differently in a heavy pedestrian environment?

Multimodal safety and efficiency

• How do you time signals to accommodate pedestrians?
• How do you time signals to accommodate bikes?
• How do you time signals to accommodate transit (buses or Light Rail Transit)?
• How do you time signals to accommodate emergency vehicles?
• How do you time signals to accommodate freight (trucks)?
• How do you time signals to accommodate heavy rail?

Regional collaboration

• Do you coordinate signals with those of another agency?

Design

Miscellaneous

• Who designs new or modified traffic signal designs? (agency staff, consultant)
• Who reviews traffic signal design submittals?
• Do you have design standards or guidelines?
• What type of vehicle detection do you use? (inductive, video, radar) – does it depend on context? Why do you use X type of detection?
• What kind of communications infrastructure do you design/maintain?
• Do you share communications infrastructure with other agencies?

Operations Support

• What elements of design do you use specifically to support the operations you need? For example, where do you locate detection zones; do you use EV preemption; do you have transit signal priority (TSP); what communications bandwidth do you need?

Maintenance Support

• What elements of design do you use specifically to support the maintenance? For example, do you have standard specifications for equipment, such as controller, cabinet, detectors, communications equipment, cables or separate conductors, external finish such as paint or galvanized steel?

Multimodal Support

• What elements of design do you use specifically to support multimodal operations?
• How do you design to accommodate pedestrians at traffic signals?
• How do you design to accommodate bikes at traffic signals?
• How do you design to accommodate transit (buses or Light Rail Transit) at traffic signals?
• How do you design to accommodate emergency vehicles at traffic signals?
• How do you design to accommodate freight (trucks) at traffic signals?
• How do you design to accommodate heavy rail at traffic signals?

Management and Administration

Personnel

• What type of training does staff receive?
• How do you retain staff?

Coordination

• Do you coordinate/communicate with adjacent agencies? If so, who does this?

Budgeting and programming

• Do you have on-going signal maintenance and operations specifically identified in your annual budget?
• Does your CIP or RTIP include replacement of signal equipment based on the estimate life cycle of each element?

Customer service

• Who responds to citizen calls?
• Who responds to Mayor's/Director's/ Manager's requests?
• Do you provide outreach to media, stakeholders on signal operations?

Step 2a – Describe Related Strategies

Based on the items listed in Step 1, think of the reasons why the agency conducts these particular activities. The answer will typically give you the strategy you are implementing through this activity. For example:

What do you do?

Tactic: Modify signal timing temporarily to compensate for equipment failures (e.g., stuck detector)

Why do this?

Strategy: Respond to citizen complaints
Strategy: Minimize impact of failures on traffic operations

Step 2b – Develop Objectives

For each strategy described in Step 2B pose the question: what are we trying to achieve by implementing that strategy? This will identify the objectives that you have for all the activities you undertake. For example:

What do you do?

Tactic: Modify signal timing (stuck detector)

Why do this?

Strategy: Respond to citizen complaint

What are you achieving?

Objective: Maintain operational efficiency of signal system or ensure that traffic signals provide equitable service to all users.

Step 3a – Identify and Link to Agency Goals

Step 3 starts with the planner in mind by reviewing your agency's planning documents as shown in step 3a. Identify the goals listed in a transportation system plan, transportation chapter of a comprehensive plan, area plan, congestion management plan, etc. Goals from the transportation system plan or the goals of the transportation division of an agency work well since they directly relate to the transportation system. Goals from an agency general plan (for example) tend to be broader or high level and relate more to the overall function of the agency. It may be more challenging to pull out transportation related goals. If your agency doesn’t have documented goals from planning documents, then you will need to develop your own goals for the signal system.

     

Transportation goals extracted from the City of Walnut Creek General Plan 2025 (Walnut Creek, 2006) are listed in Table 5. Each of the transportation goals is reviewed to determine whether or not it is relevant to traffic signal management. Those that are relevant are then carried forward, along with any related objectives that are documented.

Table 5. Example agency transportation goals.

Description of Agency Transportation Goal	Relevant to Traffic Signal Management?
Minimize future increases in congestion on regional transportation facilities	Yes
Expand and improve regional trail facilities.	No
Maintain a transportation network that provides mobility for all ages and abilities and for all areas of the community.	Yes
Protect residential neighborhoods from through-traffic, speeding, and nonresidential parking.	Yes
Provide a safe and attractive environment for bicycle travel throughout the community.	Yes
Provide a safe and attractive walking environment accessible to all.	Yes
Increase transit ridership and service to employment, schools, shopping, and recreation.	Yes
Serve as a model for other cities by providing a comprehensive TDM program that strives to decrease the use of the automobile and reduce peak-period traffic congestion.	No
Promote a pedestrian friendly downtown.	Yes
Promote safe bicycling to and through downtown.	Yes
Develop a comprehensive shuttle system serving downtown residents, shoppers, day and overnight visitors, and employees.	Yes
Provide convenient and adequate parking.	No
Provide convenient and adequate loading facilities in the Core Area.	No

Step 3b – Review Transportation Objectives

Some agencies adopt guiding principles or policies to explain the context within which their objectives are framed. In one agency's General Plan, numerous policies were described, intended to support each goal, and at the same time providing a mixture of objectives and contextual guidance. Each of these can then be assessed to determine whether or not they are relevant to traffic signal management.

The transportation policies established in the example General Plan, and an assessment of their relevance to traffic signal management, are contained in Table 6. These can be used to guide the description of traffic signal management objective in the next step.

Some agencies have adopted objectives for the different departments (including public works, engineering, transportation, etc.). If this is the case, review and compile the Objectives that relate to the traffic signal system. If your agency doesn't have documented objectives from planning documents, then you will need to develop your own objectives for the signal system.

Table 6. Example agency transportation plan policies.

Policy	Description of Guiding Policies	Relevant to Traffic Signal Management?
Goal 1:Minimize future increases in congestion on regional transportation facilities
1.1.	In cooperation with State and regional agencies and other jurisdictions, develop and implement regional solutions to local traffic problems created by growth outside the city.	Yes
1.2.	Support efforts to obtain funding for improvements to Highway 4 and other roads that provide a bypass for traffic passing through Walnut Creek.	No
1.3.	Promote off-peak start times for special events that generate traffic passing through Walnut Creek.	No
Goal 3: Maintain a transportation network that provides mobility for all ages and abilities and for all areas of the community.
3.1.	Maintain the level of service standards for designated roadways within the City's transportation network.	Yes
3.2.	Make safety, circulation, and congestion-reduction improvements without excessive community disruption.	Yes
3.3.	Promote maximum operational capacity and efficiency on arterials and collectors.	Yes
Goal 4: Protect residential neighborhoods from through-traffic, speeding, and nonresidential parking.
4.1.	Manage arterial and collector traffic to minimize adverse effects on neighborhoods.	Yes
4.2.	Discourage through-traffic on local streets and collectors.	Yes
4.3.	Prevent encroachment of nonresidential parking in existing neighborhoods.	No
Goal 5: Provide a safe and attractive environment for bicycle travel throughout the community.
5.1.	Promote bicycle use as an alternative way to get to work, school, shopping, recreational facilities, and transit stops.	No
5.2.	Provide facilities that encourage and support bicycle travel.	Yes
5.3.	Oppose the use of motorized transportation (trains, buses, autos, motorcycles) on the Iron Horse Corridor between the Pleasant Hill BART Station and Newell Avenue.	No
Goal 6: Provide a safe and attractive walking environment accessible to all.
6.1.	Provide safe and attractive pedestrian routes along arterials and collectors leading to schools, along arterials or collectors that carry high traffic volumes, on all downtown streets, along major streets leading to the downtown, and on all streets leading to transit facilities.	Yes
6.2.	Require full-frontage curb and sidewalk improvements in all commercial areas.	No
6.3.	When utility rights-of-way, drainage, or other corridors are established, obtain dedications of land or easements, where appropriate, for paths that would enhance the pedestrian system.	No
6.4.	Facilitate use of public sidewalks and walkways throughout the city.	Yes
Goal 7: Increase transit ridership and service to employment, schools, shopping, and recreation.
7.1	Encourage coordination among transit agencies in facilitating connections and transfers while minimizing delay and inconvenience.	Yes
7.2.	Encourage improvements to transit systems that connect Walnut Creek residents to regional locations.	Yes
7.3.	Link high-density residential developments, schools, employment centers, and shopping areas via transit.	No
7.4.	Offer support and funding for effective transit alternatives such as trolleys and improved shuttle services.	No
7.5.	Develop a comprehensive plan with CCCTA to install public transit amenities such as benches, passenger shelters, and walkways.	No
7.6.	Encourage provision of a variety of transportation services for seniors and members of the public unable to use conventional transit.	No
Goal 9: Promote a pedestrian friendly downtown.
9.1.	Balance the needs of drivers with downtown's pedestrian scale and existing and proposed transit and bicycle access.	Yes
9.2.	Favor pedestrian travel over vehicular travel in the Pedestrian Retail District.	Yes
9.3.	Promote pedestrian safety in the downtown area.	Yes
Goal 10: Promote safe bicycling to and through downtown.
10.1.	Link existing and planned bikeways in and through downtown.	Yes

Step 4 – Consolidate Objectives for Traffic Signal Management

Combine, review, and distill the Objectives developed in Step 2 and the Objectives from Step 3b. Now that you have described objectives that could be supported by your strategies, you should modify them and define them in a manner that is consistent with the transportation objectives identified in Step 3. These should be expressed in terms that would work for both the operator and the planner. Example TSMP objectives that have been derived using this process are contained in Table 7. For example, the TSMP objective of "operate traffic signal system at its maximum efficiency within the context of a balanced, multimodal operation, as described in current operational policies" was established to accommodate several of the agency's transportation objectives, namely:

• Maintain the level of service standards for designated roadways within the City's transportation network.
• Promote maximum operational capacity and efficiency on arterials and collectors.
• Manage arterial and collector traffic to minimize adverse effects on neighborhoods.

Table 7. Example traffic signal management objectives.

	Description
1	Provide facilities at traffic signals to safely and efficiently accommodate all road users (including transit, pedestrians and bicycles in addition to other vehicles)
2	Keep the signal operation appropriate for the current traffic conditions and consistent with current operational policies
3	Operate traffic signal system at its maximum efficiency within the context of a balanced, multimodal operation, as described in current operational policies
4	Undertake maintenance in a cost-effective manner
5	Cooperatively coordinate with neighbor agencies to develop and implement regional solutions to traffic problems related to regional issues
6	Design traffic signal system elements that are sustainable in a fiscally responsible manner
7	Maintain the traffic signal system so it always operates as intended
8	Maintain a traffic signal infrastructure that is appropriate for accommodating current mobility goals
9	Inform and educate all stakeholders of the challenge to maintain a modal balance and superior service.
10	Keep the community fully informed about the development and operation of the traffic signal system so they understand what we do and why we do what we do, so they can judge for themselves how well we are satisfying their needs.

Step 5 – Rationalize Strategies to Support Traffic Signal Management Plan Objectives

At this point you have a set of traffic signal management objectives that are consistent with your agency's transportation goals and objectives. Most of these objectives will be supported by the strategies you described in Step 2. You should now review and revise the strategies so they clearly support your revised TSMP Objectives developed in Step 4. At this point, you may choose to reword the strategies and tactics for consistency, add to them, or consolidate them. This may involve further editing the objectives to ensure that strategies you consider important are not discarded because they were not linked to an appropriately worded objective.

If you can't clearly describe an objective that would justify employing a specific strategy, you should seriously consider dropping that strategy, because it cannot be justified within the context of your TSMP. This review process also provides the opportunity to confirm that all the stated tactics are, in fact, legitimately supporting your objectives. At this point, you may need to consider dropping a tactic (even a long-standing activity) if you cannot show that it is actually supporting your objectives and is consistent with your listed strategies. Now look at the objectives brought forward from Step 4 and identify any that are not yet support by strategies and tactics. If you have any, create additional strategies what will support those objectives. You may choose to identify those strategies in your action plan for future implementation.

One way to verify that the strategies and tactics are meeting the objectives is to develop a traceability matrix. To do this, start by listing your goals and objectives, organized in a way that shows which objectives support which goals. Then for each objective, list all the strategies that support each objective. It is quite likely that some strategies will support more than one objective, so you should list those several times, under each relevant objective. Each strategy is supported by one or more tactic or activity, and each tactic may support one or more strategies. You should now list each tactic that supports each strategy. As before, this may involve listing some tactics multiple times.

Table 8 shows example goals, objectives, strategies and tactics that have been developed in TSMPs by UDOT, City of Walnut Creek and City of South San Francisco.

Table 8. Example traceability between goals, objectives and strategies.

Agency Goal	TSMP Objective	Strategy	Tactic
Maintain the transportation system in the most efficient manner possible	Undertake maintenance in a cost effective manner	Perform regular preventive maintenance on all traffic signals	Visit each intersection once per month and replace elements that are consumed in normal operation according to life cycle analysis for each element. Contract maintenance when it is more cost-effective that in-house.
Link communities through an efficient multimodal transportation network	Safely and efficiently accommodate all bicyclists at all traffic signals	Provide bicycle detection and appropriate timing at each signal	Detect all bicycles arriving at traffic signals. Adjust signal timing to safely accommodate bicycles when they are detected.
	Safely and efficiently accommodate all pedestrians at all traffic signals	Provide pedestrian detection and crosswalks for all desired pedestrian movements	Provide push buttons for all signalized crosswalks. Provide signalized crosswalks for all feasible pedestrian crossings at traffic signals. Use pedestrian detection to minimize impact of pedestrian crossing times on traffic operation.

Now you need to work upwards from objectives to goals, and also work downwards from goals to objectives. This will help you align the activities with your agency’s goals, and provide a basis for enunciating goals that have not been adequately documented so far, but are needed to clearly show justification and support for all the activities.

This then provides a vehicle for detailed reconsideration of what you do, why you do it, and will potentially lead in three different directions:

• Some activities may be determined to be unnecessary or even counter productive.
• Some goals and objectives will be seen as having no activities to support them.
• Some previously unstated goals will be documented and determined to be essential to the agency.

Step 6 – Develop Evaluation Methods

In Step 6 you select evaluation methods, measures and metrics that will allow you to assess both operational success (you are impacting traffic operations as desired) and implementation of strategies (you are effectively doing what you agreed to do). At this point, you have all the necessary elements to compile your TSMP (step 7). Within this document, we define performance measurement as the process of assessing the effectiveness of the traffic signal system in providing the desired traffic operational performance, and how well the objectives have been satisfied. This is measuring the outcomes. We define implementation verification as the process of measuring the activities undertaken by the team and determining to what extent the strategies and tactics have been implemented. This is measuring the outputs. For your operational Objectives, determine the performance measurement that is most appropriate to monitor performance. (See Chapter 4 for more information on selecting performance measures, determining data, and tracking performance of your system.)

It is best to start with one or two performance measures and build upon them as your system becomes more mature. Examples of performance measures, related directly to the operational objectives implement by City of Mesa, City of Walnut Creek and UDOT, are including in Table 9. In each of these, a single measure of performance was chosen as a determinant of success in meeting an objective. For example, an objective defined by the City of Mesa a decade ago was to provide stable travel times on specified corridors. They defined stability as limiting annual increases in average travel times to be in proportion to the changes in traffic volumes. The travel times were initially measured using floating car surveys on an annual schedule, repeating the surveys during the same week of the year. In recent years, travel times are now measure automatically and continually using Bluetooth readers, providing both a larger sample size and coverage of all periods of the day and days of the week, to allow better evaluation of the performance against the stated objective.

Table 9. Performance measures used in traffic signal management plans.

Objective	Performance Measure	Method of Measurement	Agency
Maintain stable travel times in defined corridors	Average end to end travel time on defined corridor	Floating car (annual peak hour survey) Bluetooth tracking (24/7)	Mesa
Provide predictable travel time on major arterials, consistent with traffic demand	Average end to end travel time. Reliability of travel time	Bluetooth tracking (24/7)	Walnut Creek
Provide smooth flow on defined arterials in unsaturated conditions	Percentage arrivals on green on corridor	High resolution data and Purdue Coordination Diagram	Utah Department of Transportation

Step 7 – Traffic Signal Management Plan Assembly

Now it is time to put the TSMP chapters together. Refer to the proposed Outline of Chapters in the next section to see how to compile the document. Feel free to modify this layout, just as long as you keep the intent of mapping the strategies to your agency's goals.