Elements of Business Rules and Decision Support Systems within Integrated Corridor Management: Understanding the Intersection of These Three Components

CHAPTER 2. GUIDANCE FOR BUSINESS RULES AND DECISION SUPPORT SYSTEMS WITHIN INTEGRATED CORRIDOR MANAGEMENT IMPLEMENTATION

This chapter will provide general guidance for the necessary components to develop business rules to be incorporated into a decision support system (DSS) for integrated managed corridors. As mentioned previously, the goal is not to provide detailed specifications or algorithms that someone can "plug" into a developmental DSS. Through searching, scanning, extensive conversations with contacts, and an expert panel review, there have been no documents to date that we deem to be detailed, code-level descriptions of business rules for integrated managed corridors with respect to a DSS, per se. Consequently, herein we focus on principled guidance to endorse that "business rules" should be at least implicit understandings on developing necessary components of integrated corridor management (ICM). Business rules incorporate, either by inference or actual documentation, interagency agreements, organizational and committee structures, and even tacit agreements to share information, resources, and decisions, etc. that can be used as building blocks for success.

Attaining and maintaining a successfully integrated and managed corridor that facilitates "the safe movement of persons and goods, with minimum delay, throughout the region of influence" depends on the human operator interacting with the transportation management center (TMC) systems and devices as well as other operators, managers, and agencies. One way to improve this relationship between the user and technology is through user-centered system design. The goal is to increase efficiency, comfort, safety, and ease-of-use. When applying human factors principles and procedures to TMC operation and design, Robinson, et al. (2017) and Nowakowski, Green, and Kojima (1999) identified several areas of emphasis:

• Focus on human requirements.
• Collect data on and analyze the functions, tasks, and human/machine systems.
• Make use of design principles that reduce human error.
• Employ design principles that increase human performance.
• Apply principles of job design, user aids, and data presentation.
• Use the principles of anthropometry.
• Apply principles and standards for displays and controls.
• Adhere to workplace design principles and standards.
• Design user interfaces with information systems.

If user-centered design areas are emphasized in designing and operating a TMC, several benefits will result: First, the tasks (e.g., monitoring accidents) and functions (e.g., communicating with partner entities) of the operators will be developed based on the total system, second, any deficiencies in the system will be discovered early on, and third, the use of human resources will be optimized.

HOW TO DEVELOP A DECISION SUPPORT SYSTEM WITHIN AN INTEGRATED CORRIDOR

The DSS identifies sudden or pending nonrecurring events (e.g., incidents or weather) or atypical recurring congestion-beyond-the-norm via predictive modeling. This modeling compares "that which should be" to that which is forming, thereby triggering broad response strategies. A DSS constantly mines real-time data (e.g., detectors, incidents, speeds, warnings, and weather) and evaluates and rates the response plan alternatives for recommendation to the ICM coordinator or team to identify the highest rated plan and associated mitigations. For example, in the San Diego and Dallas deployments, each DSS averages from one to five response plans per week. Monthly debriefs evaluate the systems' success and recommends any fine-tuning that might be needed.

There is no one DSS template. San Diego and Dallas, and indeed many other regions formed or forming, have developed unique approaches, any one of which satisfies the function of a DSS. A DSS can be simple or complex depending on the users' needs, the data available, and the corridor's model. A simple DSS could be a set of written incident response plans that agencies consult when an incident occurs. For the sites that the scan team visited, more-complex systems were in use and are discussed below" (Spiller et al., 2014).

Overview of "Dallas" vs. "San Diego" – The Dallas ICM system uses an expert rules system to select a pre-agreed response plan based on numerous variables (e.g., location, time of day, and lanes affected) and then uses a real-time model to validate that the selected plan will provide a benefit. The San Diego system relies on its real-time model much more and allows the model to use engineering principles and algorithms to generate a response plan for an event within the corridor. The system has the capability to be fully automated or fully manual in responding to the event. (Spiller et al., 2014, page 7-1)

The Dallas ICM process is designed to collaboratively engage the planning, technology, and infrastructure resources of the various cities and government jurisdictions along the corridor. An overview of DSS has been reproduced from the Dallas Integrated Corridor Management (ICM) Demonstration Project (Miller et al., 2015) as shown in Figure 10.

The Dallas DSS (Figure 10) provides candidate response plans to the SmartFusion (Smart Urban Freight Solutions) subsystem based on network conditions received from the SmartFusion subsystem, prediction analysis, and on a rule- based assessment of the recommended response plans. The subsystem consists of three major components: expert rules, prediction (model), and evaluation. In response to an incident, the process begins with the expert rules and the model collecting information on corridor performance and incidents from the data fusion system. The model develops an assessment of the current roadway operations based on the data received from the data fusion system. In addition, the model periodically forecasts the current and predicted performance of the network based on the current conditions and sends them to the expert rules system. Given the information about the current conditions of the network and the predicted performance of the network, the expert rules develop candidate response plans that are delivered to the ICM coordinator via the DSS dialog. The ICM coordinator approves or rejects the candidate response plan from the recommendation of the expert rules. If the ICM coordinator approves the validation decision, then the DSS pushes candidate response-plan information to the involved agency users for plan implementation. The expert rules collect the users plan readiness status and plan decision from the DSS dialog.

After implementing the ICM coordinator's plan decision, each agency user confirms the plan's operational status. The plan is terminated once the event owner agency user or the ICM coordinator closes the event in the ICM System (Spiller, et al. 2014, page 7-1).

More information about DSS Analysis Test Plans and the specific qualitative and quantitative data required is described in the Dallas Decision Support System Analysis Test Plan (Lee, 2012).

San Diego – A key element of San Diego's ICM project includes the implementation of a real-time dynamic DSS. The system uses predictive capabilities to aid stakeholders in managing and operating the corridor proactively and is composed of seven key system components, including an on-line real-

time simulation analysis and network predictive system and the application of a dynamic rule-based strategy assessment engine to generate real-time response plan strategies.

The DSS collects information on current network conditions by taking in data from an array of ITS and modal management systems, including, but not limited to, traffic signal systems, ramp metering, transit management, and freeway management systems located along the corridor. Data also includes hundreds of traffic volume and speed detectors in the roadway infrastructure and automated passenger counters and location data from transit systems, video camera feeds, and changeable message signs. Through the DSS data fusion engine, if changes in demand (based on incident or recurring conditions) are measured that meet pre-established thresholds (e.g., a minimum change in speed on the freeway of 10 mph less than free flow), the DSS generates a set of response plans containing

recommended strategies to manage the congestion. The DSS assesses the impacts of the response plans on the level of service; volume-to-capacity ratio; and speed 15, 30, 45, and 60 minutes in the future. With the DSS response plan evaluation engine, a set of response plans are evaluated and scored using a traveler, not vehicular, delay-based algorithm to derive the scores for each plan when compared to the "do nothing" case. ("Do nothing" is the base scenario where no new actions would be taken along the corridor and devices maintain normal operations.)

The response plan with the best score, representing the most congestion relief, is recommended for implementation. Once response plans are recommended, the affected agencies are notified, and the specific assets associated with a given response plan are implemented (e.g., en-route and pre-trip traveler information, corridor ramp metering, and signal coordination on arterials with freeway ramp metering). The implementation of the preferred response plan can be set to automated implementation or implementation upon approval.

Because the DSS is dynamic, it does not contain a set of predefined response plans. It was designed and built to take a performance-based approach to corridor operations and management. The business rules engine drives how response plans are implemented, how or what key actions the response plans should include, and under what conditions. The engine reflects agreed-upon regional and corridor- level operational principles discussed and set by the ICM partners. This includes, for example, how the assets available on the corridor will be used in response to certain conditions or setting constraints to reflect localized operational demand conditions (e.g., traffic cannot be rerouted onto certain arterials during school zone hours). After a plan is implemented, the DSS continues to forecast traffic conditions. As conditions change, the system continues to monitor the extent of the congestion based on the total distance upstream of the event to the end of the congestion. As congestion continues or grows, the system will re-evaluate and generate new response plans to ensure that the best strategy continues to be applied. Once the congestion starts to dissipate and the upstream length of the congestion is reduced, the system steps out of the response plan and places the device back into the normal operations for that time of day (Spiller, et al. 2014, page 7-3).

HOW TO DEVELOP AGREEMENTS: RULES TO CONSIDER WITHIN OPERATIONAL CONSTRAINTS

Levels of Formality for Agreements

For any operational project that involves multiple agencies, interagency agreements are required to manage the system and coordinate responses to any incident. These agreements can form the basis of business rules that are incorporated into the DSS, so it is advantageous to spend some time discussing ways of developing them and providing general guidance. The following examples of interagency agreements have been suggested by I-210 ICM initiatives that may need to be developed and could be useful in outlining business rules (Dion, Butler, Xuan, 2015).

The level of formality depends on the relationship among agencies and can be set as they desire. There are instances of agencies cooperating with very few formal agreements. Instead, the interactions are set based on principles and common goals in their concepts of operations, and then these are used to guide solutions on an ad hoc basis. On the other extreme, some agencies may establish very detailed agreements that try to address the range of possible situations that may arise (or develop a new agreement for each situation). Figure 11 shows potential elements of multiagency agreements.

Table 1 provides examples of the various stakeholders and potential formal agreements that may be established when developing business rules. This was originally formulated as a variety of interfaces for the DSS users, but it also is indicative of the different components (for more background, see Dion, Butler, and Xuan, 2015, p. 157, 10-10 Institutional Agreements).

Table 1. Example stakeholders and potential formal agreements that should be established when developing business rules.

Agreements and Protocols with Information Collection Systems
Caltrans uses the Performance Management System (PeMS) as its main system for collecting, processing, and visualizing freeway flow data. Traffic detection and traffic signal control systems operated by Caltrans (TransSuite), Los Angeles County (the Kimley-Horn intelligent transportation system software, or "KITS"), the cities of Pasadena (i2tms, QuicNet Pro, and SCATS®), Arcadia (TransSuite), Duarte (KITS), and Monrovia (KITS). Bluetooth data collection systems operated by local agencies. Current systems include those operated by Pasadena and Arcadia. Transit operations management systems used by Metro Bus, Metro Rail, Foothill Transit, Pasadena Transit, and any other participating local transit agencies. California Highway Patrol and its computer-aided dispatch (CAD) system. Local law enforcement agencies and their dispatch systems. Parking management systems used by operators of park-and-ride facilities participating in the project.
Agreements and Protocols for Device Control Systems
Traffic signal control systems operated by Caltrans (TransSuite), Los Angeles County (KITS), the cities of Pasadena (i2tms, QuicNet Pro, and SCATS), Arcadia (TransSuite), Duarte (KITS), and Monrovia (KITS). Caltrans uses an advanced traffic management system (ATMS) to control ramp meters on freeway on-ramps and connectors as well as post messages on freeway changeable message signs. Systems used by local agencies to post messages on dynamic message signs operating along arterials.

Potential Partners in Forming Agreements and Business Rules

Partnership with the key relevant transportation agencies is a necessary step in order to advance ICM implementation. A list of potential partners may include:

• U.S. Department of Transportation (DOT).
• State DOT.
• Metropolitan planning organization (MPO) (e.g., the North Central Texas Council of Governments).
• Transit agencies (e.g., high-occupancy vehicles (HOV), high-occupancy toll (HOT), rail, bus, etc.).
• Freight.
• County or City public works or transportation agencies that own arterials and signals.
• Local agencies responsible for parking, commuter or rideshare organizations, traveler information or 511 providers.
• Public safety services such as law enforcement, fire department, towing companies.
• Local universities.
• Toll agencies
• Private sector.

Communication amongst different partners is a vital component of an ICM implementation and can be done with a variety of interfaces and infrastructure. For example, the Dallas ICM uses the existing infrastructure from the Texas Department of Transportation (TxDOT) center-to-center system (a software system to facilitate sharing of traffic management related information and control of ITS field devices between TMCs which have a variety of different management systems). This provides direct connection to agencies not on the system with a web-based interfaced known as the information exchange system. This system interface is used for ICM stakeholders to develop and view events in the corridor as well as ascertain current conditions of field devices and congestions. It also allows for coordinating responses to incidents within the corridor. Other ICM communications platforms being tested use "the cloud" interface.

Regulatory Context

A proactive, collaborative, and strategic approach to public and private stakeholder partnerships is a key component for the successful implementation of an ICM system. Engaging these partners in developing business rules to incorporate into the DSS is critical.

Enabling Authority. An enabling authority should coordinate with all participating agencies and stakeholders. The type and level of authority varies based upon the respective agencies' roles in the system.

Policy Board (Composition, Voting, and Officers). Each participating agency or stakeholder should be able to choose its role. However, support personnel and representatives are required for each of them. Because the success of the ICM project relies on effective leadership, it is important that the selected key policy board has these features illustrated in Figure 12.

Advisory Committees. The name and number of committees will vary depending on the needs of the specific program. Figure 13 shows examples of developed committees at various implementation sites (Dion, Butler, Xuan, 2015; Gonzalez, 2012; San Diego Pioneer Site Team, 2008).

Each committee may contain subcommittees. The membership should consist of members from local jurisdictions, transit agencies, first-responding agencies, software developers, system integrators, etc.

This section provides an overview of the regulatory and committee structure of a typical managed, integrated corridor. It also provides suggestions for the types of representatives and communication vehicles (e.g., committee meetings) one may want to tap in order to gather business rules and protocols, interagency agreements, and other documents that are helpful in incorporating business rules into the DSS.

Communication Approaches

Communication amongst various stakeholders in a managed, integrated corridor is critical to successful implementation. It involves bringing together multiple agencies that utilize a variety of methods and heterogeneous systems (Gonzalez, 2012).

In the Dallas ICM effort, daily operation is coordinated through protocols and arrangements. Information is exchanged through the center-to- center project along with SmartNET (an information exchange system). SmartNET then distributes event information and response recommendations to the appropriate staff. (For more information, see the Dallas Integrated Corridor Management (ICM) Demonstration Project Final Report, by Miller, et al., 2015). For this section, we want to highlight the role this communication system plays in connecting the various stakeholders and utilizing pre-existing arrangements that were established to aid in implementation. These arrangements (or business rules) form the context and structure of the communications component to the ICM. They may be institutional protocols, memoranda of understanding between the agencies, etc. These elements contain a range of tools and systems that transform data into information that operators can use to make decisions.

This information includes:

• Computers for storing and processing the large amounts of data.
• Communications networks.
• Display devices to present information to decisionmakers.
• Storage databases.
• Devices for manual entry of data.
• Communication devices for information exchange.
• Data warehousing.
• Algorithms for data quality and aggregation.

The information sharing components are critical for efficiently implementing DSS recommendations. These also can be based on strict protocols that were pre-established during the ICM development process (and can potentially be automated by incorporation into the DSS). Operators can provide travelers information about conditions through several means:

• Media feeds – These include information feeds to local media, such as radio and television stations, but may also include in-vehicle devices or smartphone apps.
• Dynamic message signs (DMS) – These are on-road signs that provide information about conditions to the traveler (including travel time, emergency situations, transit status, etc.).
• Highway advisory radio (HAR) – This is a radio medium to provide more detailed information that may be contained on DMS.
• 5-1-1 systems (voice) – These systems can provide general messages and traffic information to the driver via a telephone voice interface (although many places are restricting phone use while driving).
• Traffic and transit web sites – Internet-based websites that provide traffic-related information.
• Mobile application.

In addition to this range of options, operators can use outreach campaigns and publicity releases. Figure 14 shows the range of approaches to communicating with the public. This range of media and approaches can all be subject to business rules and protocols amongst agencies on coordinated responses and information sharing. These rules or protocols can provide a context (with boundaries) to recommendations from a DSS that generates media- or messaging- related guidance. For example, many messages for non-recurring events (both planned and unplanned) are coordinated with public safety personnel. This coordination often has set interagency agreements governing how messaging is coordinated, which can be formulated into constraining business rules (Noblis, June 2008).

Contingencies Based on Level of Interagency Cooperation

The use of business rules in DSS (and decisionmaking in general) can be guided by each area's unique level of interagency cooperation and formal agreements. There are some regions or areas where all interactions, decisions, and protocols are clearly defined and explicitly stated. In contrast, there are examples in areas such as freight where staff at the operational level have developed relationships and make decisions based on overall principle and the strategic plans of the agencies, but formal agreements have never been developed. Instead, there is an institutional knowledge of who to reach out to when an incident occurs and what common goals are in place that then can be operationalized at the implementation level. Both approaches have advantages and disadvantages, and are not mutually exclusive (there can be a combination). The approach adopted will depend on the context.

STRUCTURAL CONCERNS

The main concerns for each site might vary depending on the nature of their system. For instance, Table 2 outlines issues identified by the I-15 corridor stakeholders. It highlights three areas, but we will focus on the institutional issues which are most relevant to business rules in DSS.

Table 2. Institutional issues relevant to business rules in the I-15 decision support system.

Technical Issues
Data archiving and accessibility for future analyses. Modifying/updating San Diego regional intelligent transportation system architecture to bring it into alignment with I-15 integrated corridor management system (ICMS) concept. Use of regional transit fare system (Compass Card) across multiple transit service providers. Expansion of functionality for 511 advanced traveler information system.
Operational Issues
Enhancing transit capacity in response to planned events and major incidents. Implementing bus signal priority for transit on arterials. Coordinating different operating systems across agencies to work together (e.g., I-15 freeway on-ramp metering signals with adjacent arterial traffic signals). Fully integrating commercial vehicle operations into I-15 ICMS concept.
Institutional Issues
Establishing policies and arrangements with private entities (parking, information service providers, and major employment centers along the I-15 corridor). Compatibility of virtual corridor transportation management center responsibilities for I-15 ICMS corridor stakeholders with their conventional responsibilities. Expansion of set of organizational stakeholders as part of the I-15 Corridor Management Team beyond those that are only transportation-focused (e.g., public health agencies). Enhanced level of inter-organizational coordination and integration among corridor stakeholders.

The following provides examples of institutional and technical constraints that may affect the implementation of a proposed ICM system in California (for more detail, see Dion, Butler, Xuan, 2015).

Table 3. Institutional and technical constraints that may affect the proposed I-210 integrated corridor management implementation.

Institutional Constraints
Due to liability issues, jurisdictional policies may not allow recommendations of specific diversion routes to be communicated to travelers. Several local jurisdictions impose restrictions on the routes that truck traffic may take across their network. This may be due to various reasons, such as the desire, to reduce safety risks, noise in residential neighborhoods, pavement damages, etc. Some jurisdictions may impose constraints on traffic signal operations during specific periods. Various regulations may govern the operation of changeable message signs. Strict regulations govern the design and installation of traffic signs and road markings. Many agencies have established operational procedures defining what to do in specific situations. Different jurisdictions may have different requirements and regulations regarding the use of information technologies.
Technical Constraints
Inadequate traffic detection may exist at various locations within the corridor. A variety of traffic signal control equipment with varying capabilities is in use within the corridor. Various centralized traffic signal control systems are used throughout the corridor. Not all traffic management centers are staffed 24 hours per day, 7 days per week. Transit agencies may not have the necessary equipment to track vehicle occupancy and relevant operational metrics in real-time. Park-and-ride facilities may not be equipped with the necessary equipment to track facility occupancy in real-time. Suitable communication or control capabilities may not exist with all existing or desired field devices.

Additional Levels of Approval

This part can be categorized as:

• Institutional: Additional approval is required for coordination and collaboration between various agencies and jurisdictions
• Operational: Agreement among all operating agencies is required on operational strategies to manage the total capacity and demand of the corridor.
• Technical: Additional agreement is required for the sharing and distribution of information, and system operations and control.

Staffing and Budget Limitations

As with any new program, staffing requirements must be considered. Agencies have staffed ICM in a variety of ways. Many add ICM duties to existing staff members' responsibilities (e.g., existing Dallas Area Rapid Transit operations staff was given additional duties). However, the agency did fund one full-time equivalent to serve as the ICM coordinator for the US-75 corridor.

In general terms, operations have continued as part of the ongoing operational roles of the agencies involved. System support for ICM has been outsourced to private companies for the development and ongoing operation and maintenance of the software and hardware used for ICM programs. However, depending on staffing constraints, technical capabilities could be provided by any combination of public agencies and/or private companies. This should be considered a long-term commitment for an ICM program. (Spiller et al. 2014, page ES-3)

The operational needs for an integrated corridor management system (ICMS) are further explored in the white paper "Conceptualizing Integrated Corridor Management."

The "Conceptualizing Integrated Corridor Management" white paper (Noblis, 2008) discusses 23 possible operational needs of an ICMS. The unique number and title of each need are listed below:

1. Need for communication with transportation network users.
2. Need for interactive communication with colleagues.
3. Need for standard definition of customary operations.
4. Need for transportation system operators and public safety organizations to coordinate.
5. Need to manage the supply of services to match demand.
6. Need to have competent and well-trained staff.
7. Need to monitor the location and status of vehicles within corridor management agency fleet(s).
8. Need to visualize information.
9. Need to share control of devices within a corridor.
10. Need to monitor the effectiveness of control tactics implemented in the corridor.
11. Need to understand demand for transportation services.
12. Need to monitor threats to the corridor.
13. Need for corridor performance measures.
14. Need for impact assessment tools.
15. Need to archive data.
16. Need for descriptive data about corridor infrastructure.
17. Need to have a quality information processing infrastructure.
18. Need to monitor corridor status.
19. Need for real-time or near real-time information.
20. Need for non-real-time data (e.g., sample data).
21. Need to collect and process data in real-time or near real-time.
22. Need to monitor the status of the physical transportation infrastructure.
23. Need to have quality physical infrastructure.

The white paper provides a detailed description of each of these needs listed above and the following actions are recommended:

• Make a list of resources to finance the project.
• Try to find a way to make profit with the newly developed system to be able to fund ongoing operation (for example, develop a smartphone app).

The Los Angeles I-210 Pilot system identifies the following key groups of individuals to be involved in the operation of the ICM system (Dion, Butler, Xuan, 2015):

• ICM corridor manager.
• ICM system manager.
• Core system operators.
• Information providers/consumers.
• Technical advisory and management committee.
• Connected corridors steering committee.
• Caltrans traffic management center operators.
• Caltrans operations division staff.
• County/city traffic management staff.
• Transit dispatchers.
• First responders.

Maintaining Balance among Participating Jurisdictions

Once agreements are established and business rules are ready to be incorporated into recommended decisions, it is important not to assume the task is complete. Agencies, structures, and context continue to change, and the agreements can quickly become outdated. One should consider these agreements to be living documents that continue to reflect the current operational environment (and not as a snapshot in time from when it was established). They must be revisited and updated as needed (Gonzalez et al., 2012). Getting agreements is difficult, but so is constantly having to update it, a process which requires board and governing body approvals. Once a blanket agreement is in hand, it is best to consider operations and maintenance manuals as living documents.

Establishment of New Partnerships

Interjurisdictional and interorganizational coordination and integration among corridor stakeholders is necessary for the establishment of new partnerships.

• Invite all potential agencies from the beginning.
• Motivate by educating them about the benefit of the system to them.
• Keep them motivated.
• If they decide not to be a part of the team, keep them in the loop, they may decide to join later in the process.
• Give them a leadership role like chairing committees will be helpful.

DIFFERENCES IN INSTITUTIONS

Every ICM implementation site will have its own unique landscape, culture, and set of institutions. This context will shape the agreements and partnerships that are formed, along with the "personality" of that ICM implementation. It is out of the scope of this guidance to outline all of the different characteristics of potential partners and structures of managed, integrated corridors. However, we would like to highlight several categories of which to be mindful when establishing interagency agreements and eventual business rules for decision making. Figure 15 depicts some of the many ways that agencies may differ in their oversight duties.

• Differences in agency legislation (at the State, county, or city levels), laws, and funding sources. State agencies may have completely different structures and funding concerns than city or county agencies. These factors should be considered.
• Differences in State transportation agencies. Each DOT has its own unique character, ways of operating, leadership direction, etc. Culture in an organization and leadership presence should not be underestimated in impacting business rules and operational execution.
• Differences in local jurisdictions. Similarly, the local context and partners will influence the types of agreements made. Does the local jurisdiction work well with the local branch of the State DOT? Do they have the same goals?
• Differences in Public transit partners and funding sources. Transit partners are key to a successful ICM implementation, and they are the most seasoned at developing multimodal and multijurisdictional agreements.
• Differences in State financial resources. These resources can have a large impact on the type of ICM, its DSS, and the ability to enact agreed upon response plans. If there are not enough resources, then the response plans may not be practical and coordination will be inhibited.
• Differences in ownership of the roadway system. This is often overlooked, but different segments of the roadway system can have different owners with a range of goals. And, it is not unusual for those goals to be in conflict at times. Consequently, ownership rights and goals can impact the success of the ICM, as well as how flexible the business rules can be with respect to partner priority and coordination.