Expanding the notion of System Performance

by Robert Stanley

ISTEA Planners Workbook

Overview of Management Systems Under ISTEA: the enactment of the Intermodal Surface Transportation Efficiency Act of 1991, or ISTEA, has introduced fundamental change in the procedures and processes we have traditionally used to plan, build and operate the network of transportation facilities and services that move people and goods. In both the letter of the law and in its broad intent, ISTEA emphasizes a number of key themes. Among them is the need for:

• Improved performance on the surface transportation system;
• Better connections and interrelationships between and systems and services to create a "seamless network;"
• Increased travel and transportation options and better balance among the options available;
• Greater efficiency in utilization of scarce funds;
• Broader involvement and participation in transportation decision-making; and,
• Greater attention to fundamental community and national goals in evaluating and selecting transportation investments, improvements and actions.
  

In a word, what ISTEA requires is far more effective MANAGEMENT of our current and future transportation network and transportation resources.

The theme of better managing our transportation network has been reinforced in ISTEA by a specific requirement that each state design and institute a series of six new, interrelated "management and monitoring systems."1

Each of the six new management systems listed in Figure 1 are intended to enhance our ability to diagnose existing and potential problems throughout the entire surface transportation network, and to evaluate and prioritize alternative strategies, actions and solutions. The use of the management systems is intended to improve, not replace, the overall planning process, as well as improve the performance of the transportation network.

The nature, scope and use of these management systems is still being debated at the state and local level. They must, however, be fully operational by October 1, 1996, in most cases.

The sections below outline in more detail the nature of the ISTEA management system requirements generally and the unique features and characteristics of the Congestion Management System (CMS) in particular.

(1) The required management systems are described in Section 1034 of the Intermodal Surface Transportation Efficiency Act. On December 1, 1993, the U.S. DOT issued guidance to implement Section 1034 entitled, "Managing and Monitoring Systems, Interim Final Rule," which describes the scope and nature of each of the systems. In simplest terms, the management systems can be thought of as computerized databases that contain shared information on both the physical facilities and the operations of the entire surface transportation system. In addition to housing information that can be applied in a wide range of analyses and decision-making, the management systems are expected to contain built-in analysis routines that assist in evaluating current conditions as well as alternative plans and strategies. It is assumed that each of the management systems themselves will be linked with one of another, and that they will be accessible to a variety of outside users, including local agencies, MPOs, transit agencies, research organizations and others.

Figure 1

* In addition to the six management systems noted above, a seventh system is required in ISTEA, the "Traffic Monitoring System for Highways," or TMS/H. Because states and localities already conduct extensive traffic monitoring, the purpose of the TMS/H requirements in ISTEA is to enhance current traffic monitoring practices to support the other six management systems.

Purpose of the ISTEA Management Systems: the management systems are intended to provide additional information and improved analysis to support development of metropolitan and statewide transportation plans, programs and projects. In particular, management systems are expected to improve the establishment of project funding priorities across modes and the analysis of trade-offs among the full range of potential transportation investments being considered.

The ISTEA Interim Final Rule also defines management systems as, "a systematic process (emphasis added), designed to assist decision-makers in selecting cost-effective strategies/actions to improve the efficiency and safety of and protect the investment in, the nation's transportation infrastructure." 2

2"Managing and Monitoring Systems: Interim Final Rule," Federal Register. December 1, 1993. p. 63476.

Each of the management systems are expected to involve or include:

• Data collection and analysis;
• Identification of performance measures;
• Determination of needs;
• Evaluation and selection of strategies/actions to address needs; and
• Evaluation of the effectiveness of the implemented strategies/actions.
  

In other words, management systems are expected to enhance the traditional transportation planning process at both the project planning and system levels by providing more systematic and comprehensive data and analyses across the network as a whole.

Management System Development Schedule: development of the ISTEA management systems is to take place over the 1994 to 1998 period, with various milestones to be achieved for each system in that timeframe. Figure 2 highlights the management system development schedule that generally includes:

• Submission of "work plans" by October 1994;
• Limited implementation and application of each system by October 1995; and
• Full implementation of each by October 1996, 1997 or 1998.
  

• Who is Responsible for Management System Development: the primary responsibility for management system development lies with the state, although it is anticipated that each state will tailor its management systems to meet state, regional and local goals, policies, resources and conditions.

The states, in turn, are directed to coordinate development, establishment and implementation of the management systems with designated Metropolitan Planning Organizations (MPOs), local officials, federal transit grant recipients and other agencies that operate affected transportation systems or facilities. In addition, the states are allowed to enter into agreements with these agencies to develop or implement any part of or all of the management systems subject to state coordination.

Generally, states have designated specific staff from state DOTs to lead development of each management system, and have convened management system users and participants to help guide the initial development effort.

The Focus of Various Management Systems: Assets vs. Performance: the ISTEA management systems are different in their basic character and scope. Three of the systems -- pavement (PMS), bridge (BMS) and transit (PTMS) -- are asset-oriented systems. Their major purpose is to inventory and track the condition of various elements or components of the network and assist in establishing cost-effective capital investment strategies to get the maximum use from facilities and services.

Three other management systems -- safety (SMS), congestion (CMS), and traffic monitoring (TMS/H) -- are focused more directly on the performance and operation of the transportation network. The intermodal management (IMS) system combines both asset and performance management features.

To be used most effectively, the various management systems must draw on common or shared databases and information covering all elements of the network and their performance. Ideally they are intended to inform and support planning and decision-making at all levels, from project-specific planning, to multi-year budgetary planning, to long-range strategic planning.

The Congestion Management System -- Multimodal System Performance: the Congestion Management System, or CMS, is one of the more innovative and challenging of the six management systems. Congestion management not only implies a direct customer orientation to planning and investment, it can potentially provide a mechanism to measure directly the economic and environmental consequences of current system performance and future proposed improvements.

The specific requirements of the Congestion Management System are to formulate measures of performance applicable to all modes, monitor conditions on the entire transportation system network, identify where congestion problems are most severe, and to evaluate the impact of various congestion mitigation strategies to relieve current or projected levels of congestion. In particular, the CMS is intended to provide the basis for analyzing all reasonable alternatives to expanding single-occupant vehicle highway capacity in Transportation Management Areas, or TMAs (areas of over 200,000 population) that are in non-attainment status for carbon monoxide or ozone.

These objectives make the CMS unique in at least three respects:

1. It focuses directly on system performance and efficiency and calls for broader, multimodal performance monitoring;
2. It is intended for use in examining strategies for reducing single occupant vehicle (SOV) use; and,
3. It provides a direct, formal link to planning required under the 1990 Clean Air Act Amendments.
   

Measuring System Performance and Efficiency: critical to the concept of congestion management as outlined in ISTEA is the notion that the "acceptable" threshold levels of congestion will vary from locale to locale, and across different transportation modes and systems, and that the CMS should reflect local determinations of what constitutes an agreed-upon norm or threshold level.

Traditionally, congestion has been measured independently for different modes. A variety of statistical measures have been used to relate the capacity of a particular facility to the volume of use on the facility. A concept called "level of service," or LOS was intended to capture a variety of qualitative as well as quantitative aspects of travel. As a practical matter, however, levels of service are typically determined by one or two statistical measures of effectiveness relating volume and capacity.

In the context of ISTEA, however, many traditional measures, taken individually, are considered too narrowly focused because they tend to emphasize vehicle movement rather than person movement, they are oriented toward expanding rather than managing the supply and capacity of existing facilities, and they tend to emphasize problems and deficiencies rather than options and alternatives. The CMS requirements of ISTEA call for a broader and more multimodal assessment of system performance that is geared more to issues of mobility, access and the quality of the entire travel experience.

Fundamental to the development of a CMS, therefore, is the identification of a broader array of performance measures that eliminate the shortcomings of a traditional traffic engineering approach to congestion measurement and can be used to evaluate all modes and improvement strategies. In simplest terms:

Congestion management requires measures that identify the degree to which travel time and/or delays are within locally agreed upon ranges or norms;

• Mobility measures must include the extent to which options are available as well as their relative travel time and costs; and,
• Access measures must incorporate the characteristics of the land use and development patterns as well as transportation system operating characteristics.
  

A wide variety of measures covering these aspects of congestion management are available or currently in use. In addition, a wide range of data is typically available that will be critical in CMS development. Recognizing the need to monitor person movement more effectively (rather than just the movement of vehicles), the Interim Final Rule provides examples of measures that directly address person travel, including the number of persons using HOV (or preferential facilities), the proportion of persons congested or delayed, person hours of delay and vehicle occupancy counts. Clearly, however, no single measure (or small combination of measures) will adequately capture the conditions in all areas, or allow adequate analysis of alternative strategies or congestion mitigation measures.

One of the most useful resources in examining and selecting appropriate CMS performance measures is a document prepared in part by Cambridge Systematics, Inc. and others for the Federal Highway Administration entitled, "Congestion Management Systems: Metropolitan Planning Technical Report," Report No. 2, July 1994. The report summarizes current CMS development efforts in selected states and presents an overview of analytical procedures to support a CMS, including a literature review and a comprehensive review of performance measures in the broad framework highlighted above.

The selection and application of performance measures for a CMS (locally or at the state level), however, requires consideration of several factors. Figure 2, taken from the July FHWA Technical Report, identifies the evaluation criteria that should be considered in selecting CMS performance measures of any type.

Figure 2

Evaluation Criteria for CMS Performance Measures

• Area Type, Facility Type and Scale of Use
• Applicable to large urbanized areas, small-to-medium areas, or rural (or non-urban) areas
• Can discriminate between freeways and other surface facilities
• Usable at the regional, subarea, or corridor level
• Usable for individual transportation projects
• Capable of being reported at the state level
  

Multimodal and ISTEA Relationships

• Applicable to the movement of persons and goods
• Relatable to other ISTEA management systems, especially IMS, PTMS, and SMS
• Interpretable with respect to user cost, air quality, safety, economic, and general quality-of-life measures
  
  

Temporal Issues

• Capable of discriminating between peak period, off-peak, and daily congestion levels
• Can address seasonal congestion associated with tourism, agricultural harvests, etc.
• Capable of expressing the magnitude, spatial, and temporal extent of congestion
  

Technical Analysis and Data Requirements

• Constitutes a direct measure of congestion
• Capable of diagnosing transportation system deficiencies; a "triggering" device that will cause further study to occur
• Relatable to existing data collection and analysis methods
• Understandable to the transportation profession and the public
• Relatable to thresholds; how well the system is performing
• Capable of being forecasted
• Capable of supporting evaluation of congestion management and mobility enhancement strategies

Source: Congestion Management Systems: Metropolitan Planning

Technical Report, FHWA Report No. 2, Cambridge Systematics, Inc. et al, July 1994.

Congestion Management Strategies for Improving Performance: considerable effort is underway in many areas of the country to evaluate actions and strategies that may prove to be useful in controlling or reducing congestion. Much of the analytical work has been triggered by interest in identifying actions that are most effective in reducing mobile source emissions as part of Clean Air Act compliance efforts. The results to date show, not surprisingly, that: (1) no single strategy can be expected to address the majority of the problem; and, (2) strategies easiest to implement tend to be least effective and those that may be most effective are the most politically difficult to enact. The same observation is generally true for congestion management and mitigation. A range of strategies and actions are needed and the menu must be tailored to the particular area and circumstances under consideration.

The Interim Final Rule on CMSs explicitly identifies a series of strategies that should be considered, taking care to indicate that the list provides examples only and is not intended to be all-inclusive. The strategies noted in the rule are contained in Figure 3.

Figure 3

Interim Rule Congestion Management Strategies

1. Transportation demand management measures
2. Traffic operational improvements
3. Measures to encourage HOV use
4. Public transit capital improvements
5. Public transit operational improvements
6. Measures to encourage the use of bicycle, pedestrian and ferry systems
7. Congestion pricing
8. Growth management and activity center strategies
9. Access management techniques
10. Incident management
11. Intelligent transportation systems (formerly referred to as IVHS)
12. Addition of general purpose lanes
    
    

Relationship of a CMS to Other ISTEA Management Systems: the Interim Final Rule of ISTEA monitoring and management systems states that, "because of their interrelationship, the development, establishment and implementation of the CMS shall be coordinated with the development, establishment and implementation" of the PTMS and IMS. In addition, there are linkages that must be considered in data and performance measurement between a CMS and the traffic monitoring system (TMS/H), as well as the safety management system (SMS).

Common to the development of all the management systems is the need to use the systems to identify and evaluate alternative actions and strategies, and to evaluate the effectiveness of those projects and plans that are carried forward. As a result, the coordination of the CMS with other management systems is likely to initially involve: (1) shared or common data; and (2) shared or common performance measures.

Ultimately, the relationship between individual management systems will include mechanisms that are used to apply management system results to state and metropolitan decision-making. At this level, it may be expected over time that existing agencies and organizations may "reengineer" their decision-making processes and perhaps even their organizational structure as part of the implementation of new management systems. Review of organizational structures, missions and decision-making processes is, in fact, taking place in several states in parallel with -- and triggered by -- the need to develop the ISTEA management systems and new multimodal planning efforts.

Congestion Management Systems, SOV Use and Clean Air: pursuit of clean air objectives and enhanced management of the transportation network through the use of a CMS obviously go hand-in-hand. The Interim Final Rule on management systems, other planning provisions of ISTEA, and provisions of the Clean Air Act Amendments all note or reflect the close linkage between a CMS and air quality planning. Among the most important of these linkages are:

Interim Final Rule requirements to consider strategies that reduce SOV use, as discussed above;

• ISTEA language that requires highway projects that increase SOV capacity in non-attainment Transportation Management Areas (TMAs) to be part of an approved CMS; and,
  
• Interim Final Rule requirements that strategies resulting from the CMS be coordinated with the development of transportation control measures as part of State Implementation Plans.
  

As suggested earlier, however, the role of the CMS extends beyond the achievement of air quality objectives to include monitoring mobility, goods movement, multimodal system utilization and overall transportation system performance. As a result, it is important to recognize that congestion reduction strategies examined in a broadly configured CMS may not always have comparable air quality benefits. As a result, state and local officials have to determine the extent to which the CMS will or can support required air quality analysis. Approaches could range from simply monitoring VMT, speed and congestion within the CMS, to use of the CMS to develop emission inventories and trigger determinations of conformity.

The relationship of a CMS to air quality planning and evaluation can be assessed in several dimensions. The first is common data requirements. Traffic volumes, vehicle speeds, the mix of vehicle types, vehicle occupancy, mode splits, time factors and many other data elements are fundamentally important in monitoring the achievement of both air quality and congestion objectives. In addition, factors and data that are of greater importance for air quality purposes could also be incorporated into a CMS database, with the effect of enhancing both the CMS and its use in air quality planning. Examples include vehicle acceleration data, speed changes and related information.

A second area in which the CMS/clean air linkage can be established is in development of performance measures for use in the CMS. Typical measures of congestion like level of service and travel time delay may be of limited use in air quality analysis. Similarly some measures that are discussed in CMS development are more directly applicable in air quality planning than in congestion measurement, including average vehicle occupancy or mode share.

A final area in which the relationship of a CMS and air quality planning and analysis might be strengthened is in evaluation of mitigation strategies and related actions. Because the CMS is to be used to evaluate various strategies for congestion reduction, and because many of the strategies, as suggested by Figure 4, are also considered Transportation Control Measures (TCMs) within the context of air quality planning, a CMS could eventually provide a means of calculating emissions reductions or otherwise evaluating the impacts of TCMs required in non-attainment areas under the Clean Air Act. TCMs under consideration in a region should, therefore, regularly be analyzed as part of the battery of actions proposed in or emerging from the application of a CMS.

The potential relationships between a CMS and the process of monitoring and evaluating clean air compliance are so broad that neither activity should be pursued without a thorough understanding of scope, status and progress on the other, including the sustained involvement of the agencies and actors responsible for each.

An Example:

CMS Principles for Albany, New York

Metropolitan areas throughout the country as well as states are not only developing the required work plans to be followed in establishing a CMS, in many cases they are beginning CMS implementation. Among the efforts documented in the July 1994 FHWA report is activity in Albany, New York. Summarized below are seven principals that were adopted by the Capitol District Transportation Commission to guide selection of performance measures and development of strategies:

1. Management of demand is preferable to accommodation of single-occupant vehicle demand growth.
   
2. Cost effective operational actions are preferable to physical highway capacity expansion.
   
3. Land use management is critical to the protection of transportation system investment.
   
4. Capital projects designed to provide significant physical highway capacity expansion are appropriate congestion management actions only under certain conditions.
   
5. Significant physical highway capacity additions carried out in the context of major infrastructure renewal are appropriate only under certain conditions.
   
6. Incident management is essential to effective congestion management.
   
7. Corridor protection and official street mapping are necessary to preserve options.
   
   

Collaborating on Congestion Management: much of the activity in response to ISTEA has been focused on realignment and expansion of the participatory and public involvement processes that have long been a relatively pro forma feature of transportation planning. Several themes and new directions are worthy of added emphasis with respect to the new cooperative / collaborative / consultative nature of transportation planning and decision-making in the ISTEA era.

The general nature of collaborative action under ISTEA has changed in several broad ways. First, traditional participatory processes in the past were applied almost exclusively in consideration of capacity expansion projects and programs. The decisions involving maintenance and management of existing systems -- both physically and functionally -- were routinely made by planning and engineering professionals using relatively narrow technical bases that addressed the conditions or performance of individual modes.

Today, maintenance of existing systems both physically and functionally is synonymous with the overarching goal of ISTEA --increasing the efficiency of the transportation network. Expansion of the participatory process into this area requires additional progress on two broad fronts: (1) new technical knowledge and understanding on the part of non-professional participants; and (2) a much broader perspective by transportation professionals who have traditionally focused on traffic operations between the right-of-way lines of street and highway facilities.

A second change in the collaborative nature of system planning and management under ISTEA is expansion in the numbers and types of participants that have an assumed or professed interest and stake in the decisions that result from both traditional planning activity and from new initiatives like management system development. New players need to be brought productively into new processes as those processes are designed, whether they are management systems or the "reengineered" business processes that management systems are intended to support. Development of a CMS provides a major challenge and opportunity in expanding the participatory nature of ISTEA planning activity.

Key Areas for Collaboration and Coordination: development of ISTEA management systems is well underway in every state. Initial activity has generally involved assembling teams of professional staff members, designing procedures for use in preparing required management system work programs, and beginning initial management system development tasks. Typically the initial tasks involve review of agency planning and decision-making processes, review of current databases, review of existing computer systems and their capabilities, and discussion of the performance measures that might be incorporated into the management systems.

Cooperation between various public agencies in development of the ISTEA management systems is required. In every state, the activities noted above include to varying degrees the involvement of Metropolitan Planning Organization (MPO) officials, local officials, and affected agencies receiving assistance from the Federal Transit Administration (FTA), including private owners and operators. There is significant variation, however, in how this consultation is taking place and the scope of activity involved. Not all participants are likely to feel their involvement is adequate or productive.

In carrying out the required coordination activities, many states have designed participatory processes that involve both "in-reach" activities with the staff of affected government agencies, and "out-reach" activities that involve contacts and coordination with agencies outside those directly responsible for management system development and use. In some instances, states are making contacts with various user groups, like shippers, to gain a better understanding of the issues and problems that users experience. This information can help shape the kinds of data, performance measures, analytical procedures and strategies that might be incorporated into the CMS as well as other management systems.

With respect to broader public involvement in general, however, there are no explicit requirements of state or local agencies to provide an independent public participation process in development of the ISTEA management systems. The rationale for this approach, contained in the Interim Final Rule, is that since use of the management systems will result in proposed activities to be considered within the overall transportation planning and decision-making process, and since public involvement requirements of ISTEA are firmly stated for the overall planning and decision-making processes, public interest in the scope and application of the management systems can be addressed within the overall planning process.

Whether this approach is considered adequate or not, there are a number of issues on which interested parties should focus during the ongoing management system development process. Many of the aspects of management systems that may be of greatest importance to the broader community of interests have been touched on above, including:

• Parallel efforts to reformulate agency goals, missions and business practices;
• The specific goals and objectives to be established for the CMS and other management systems;
• Scope and content of the CMS, e.g., data requirements, performance measures being considered, scope and extent of the CMS network in particular, etc,.; and
• Emerging proposals for how the output of the CMS is to be used with respect to long range and strategic system planning, policy planning and development, and project planning and funding decisions.
  

Decisions on all of these matters are likely to be very fluid at this time and will certainly be the subject of continued discussion through the next year across all the states as management system implementation begins in earnest.

While each state is well on the way to meeting the ISTEA management systems requirements, the usefulness of the management systems individually and in combination over the long term will depend, to a considerable degree, on how effectively the systems reflect the concerns and interests of customers in combination with the interests of system owners and operators. Being mindful of this customer orientation should provide an impetus for a wide variety of interests to closely follow if not seek opportunities to directly engage in the continuing process of management system design. Between September 1994 and January 1995, the development and submittal of required management system work plans to the Federal Highway Administration division offices and Federal Transit Administration regional offices provides one potential opportunity to better understand the directions that are being taken in response to the management system requirements of ISTEA.

Appendix 1

Potential Roadway CMS Performance Measures

Time-Related Measures

• Average Travel Speed
• Average Travel Time
• Average Travel Rate
• Travel Time Contours
• Origin-Destination Travel Time
• Percent Travel Time Under Delay Conditions
• Percent of Time Average Speed Below Threshold Value
  

Volume Measures

• Vehicle-miles per Lane Mile
• Traffic Volume
  

Congestion Indices

• Congestion Index
• Roadway Congestion Index
• Texas Transportation Institute Suggested Congestion Index
• Excess Delay
  

Delay Measures

• Delay per Trip
• Delay per Vehicle Mile of Travel
• Minute-Miles of Delay
• Delay due to Construction/incidents
  

Level-of-Service Measures

• Lane-miles at/of LOS "X"
• VHT/VMT at/of LOS "X"
• Predominant Intersection LOS
• Number of Congested Intersections
  

Vehicle Occupancy/Ridership Measures

• Average Vehicle Ridership
• Persons/vehicle
  

Source: Congestion Management Systems: Metropolitan Planning Technical Report, FHWA Report No. 2, Cambridge Systematics, Inc. et al, July 1994.

Appendix 2

Potential Transit / Travel Demand Management CMS Performance Measures

Population Served

• Route Spacing
• Frequency of Service
• In-Vehicle Travel Time
• Travel Time (Origin-to-Destination)
  

Person Miles of Travel

• Person Hours of Travel
• Modal Shares
• Vehicle Occupancy
• TDM Program Coverage
  

Transit Hours per Capita

• Non-motorized Facilities Coverage
• Riders Per Vehicle Mile
• Riders Per Vehicle Hour
• Peak Load Factors
  

On-Time performance

• Cost Per Rider
• Vehicle Hours Per Employee
• Vehicle Miles Per Employee
  

Source: Congestion Management Systems: Metropolitan Planning Technical Report, FHWA Report No. 2, Cambridge Systematics, Inc. et al, July 1994.