Broadening Integrated Corridor Management Stakeholders (2020)

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A P P E N D I X E Analysis Methodology, Tools, and Plan E-1 As part of the Federal Highway Administration (FHWA) Traffic Analysis Toolbox (Volume XIII), the Integrated Corridor Management Analysis, Modeling, and Simulation Guide18 (updated in 2017) was designed to help corridor stakeholders implement the ICM Analysis, Modeling, and Simulation (AMS) methodology successfully and effectively. This appendix condenses the main points, namely, the value, approach, challenges, and resources required of each of the five work steps included in the AMS Guide. For more in-depth details on this methodology, please refer to FHWA’s full report. Introduction to Integrated Corridor Management Analysis, Modeling, and Simulation The ICM initiative developed an AMS methodology to assist corridor managers in forecasting and assessing the potential benefits and implications of ICM in their corridors of interest. The ICM AMS Guide has been incorporated into the Federal Highway Administration (FHWA) Traffic Analysis Toolbox (Volume XIII) and Traffic Simulation Guidelines (Please visit the FHWA Traffic Analysis Toolbox web page for more information: http://www.ops.fhwa.dot.gov/trafficanalysistools/index.htm). Unlike traditional corridor studies, which often focus on a specific element of a corridor (i.e., a freeway or freeway and frontage road during a specific time of day), ICM AMS is a comprehensive approach that analyzes different operational conditions across time and modes and across a large enough geographic area to absorb all impacts. The complexity involved in this type of analysis goes far beyond what is typically required for more traditional types of transportation investments. The potential inclusion of multiple facility types (freeway and arterial) and multiple transportation modes, combined with the potential for road use pricing influences, complicates the analysis. The focus of the ICM strategies on non-typical operational scenarios (e.g., high demand, incidents, and inclement weather) adds further complexity to the assessment. Finally, the ICM AMS methodology enables a more sensitive analysis of corridor-level performance. Traditional travel demand models are sufficient for analyzing the impacts of major infrastructure investments, such as new freeways. However, when agencies are interested in fine-tuning transportation operations strategies to produce system-wide improvements that optimize existing infrastructure performance, they need time- and space- dynamic tools that are more sensitive and that enable insight into the benefits that are otherwise too marginal to see in traditional modeling. The ICM AMS approach is neither inexpensive nor easy to accomplish. However, the value gained outweighs the expense and pays dividends throughout an ICM Initiative by reducing the chance of very expensive missteps in implementation; streamlining the implementation process; and allowing corridor stakeholders to deploy ICM AMS more rapidly and at a lower cost, given the lessons learned in this effort. 18 FHWA, Traffic Analysis Toolbox Volume XIII: Integrated Corridor Management Analysis, Modeling, and Simulation Guide, FHWA-JPO-16-397, February 2017.

E-2 Broadening Integrated Corridor Management Stakeholders implications associated with mode shift), mesoscopic simulation (utilized to analyze regional strategies such as traveler information and pricing), and microscopic simulation (ideal for analyzing traffic control strategies), the ICM AMS methodology enables robust hypothesis modeling under a range of operating conditions of interest to the corridor for more informed decision-making. This produces improved analysis as compared to travel demand models alone because the combined tools yield more accurate travel times and speeds through the corridor, more in-depth understanding of bottleneck locations and their root causes, and an understanding of the influences beyond the periphery of the corridor that underlie corridor demand. The use of the different models allows specific strengths of the individual models to be combined: travel demand models provide estimates of long-term travel demand changes resulting from capacity changes or pricing strategies, while more focused meso- and microsimulation models assess short-term operational impacts during specific non-recurring congestion conditions. The AMS approach is intended to be a flexible and iterative process adaptable to a wide variety of conditions, strategies, and situations. This flexibility is intended to provide practitioners with sufficient structure to enable a rigorous analysis suitable to complex strategies that at the same time is not so rigid as to limit the ability to restructure and rerun the analysis to address project contingencies as they occur. The AMS approach is designed to be implemented in conjunction with the ICM system development and design process (the ICM implementation process follows the systems engineering life-cycle process), and to provide a tool for continuous improvement of corridor performance. Regular periodic conduct of ICM AMS also supports continuous improvement of the supporting ICM system, and the models themselves. As the AMS process continues in parallel with the ICM system development and design process, it is likely that new strategies, alternatives and scenarios will emerge that will need to be evaluated within the AMS process; therefore, the flexibility to foresee and account for several iterations of analysis is critical. The design process may reveal new strategies or alternatives that may need to be analyzed in the AMS, prompting modifications to the AMS structure. Likewise, the AMS process may reveal parts of the concept of operations that are unworkable or uncover opportunities that may be leveraged that result in changes to the ultimate ICM design. The advanced analysis capabilities of the AMS approach provide practitioners with enhanced opportunities to conduct detailed alternatives analysis to identify optimal combinations of strategies and to test and refine how the strategies may be most optimally implemented. Due to the complexity and resources required of the AMS, this level of analysis is typically most appropriate in the later planning stages after the preliminary screening of alternatives has winnowed out a smaller set of strategies and alternatives to be evaluated. The AMS will often continue through the design phase—being used to fine-tune strategies in an iterative function as the realities of the design process progress or to assess the impacts of sequencing the improvements to identify the optimal deployment phasing of the strategies. However, these greatly expanded analysis capabilities come at a cost. The AMS approach is demanding in terms of data needs, staff skill levels, and the amount of time and resources that need to be devoted to implement and conduct the analysis successfully. Practitioners should not underestimate these requirements. Caveats to practitioners include: One of the defining features of the ICM AMS methodology is that it enables agencies to understand system dynamics at the corridor level. The ICM AMS methodology uses corridor-level performance metrics in addition to facility-level metrics to evaluate and understand corridor performance. The ICM AMS methodology accomplishes this through the combined use of multiple classes of available modeling tools. By combining aspects of macroscopic simulation (i.e., travel demand modeling (TDM), good for analyzing Significant data are needed to conduct the analysis. These data need to be high quality, reliable, and provide continuous coverage over long periods of time (minimum of six to 12 months) to be of use to the AMS process. If data fitting the requirements of the AMS are not readily available, the costs and

Analysis Methodology, Tools, and Plan E-3 travel times, travel speeds, and even origin-destination information can now be obtained inexpensively from private-sector data sources. Traffic volumes however are still needed at many locations in the analysis network. Staff skill levels must be suitable to the challenge. The complexity of not only using advanced travel demand models and simulation models independently, but also integrating and calibrating these multi- resolution models is challenging even to many advanced users. Agencies with only cursory or even intermediate skills in any one of the modeling platforms should plan either to add budget for staff training or to acquire consultant services to meet these needs. Even if data are available and staff skills are robust, the cost of compiling and analyzing the baseline data, developing the analysis framework, calibrating the tools, and completing the analysis is significant and should only be undertaken in situations where the risk of making a poor investment decision outweigh the costs. Successfully completing the AMS process for an ICM or other strategy analysis is neither inexpensive nor trivial; however, the potential cost savings from avoiding wrongly focused deployments based on inadequate analysis, along with the maximization of potential ICM system benefits through the optimization of the strategies can result in a substantial payback on the investment in AMS. For the Pioneer and Demonstration Sites, the costs of developing and conducting the AMS accounted for approximately five percent of the overall deployment budget. The AMS costs for the Pioneer and Demonstration Sites were likely proportionately higher than they would be in future analysis, due to the need to develop and refine new analysis methods and procedures. Hopefully, the best practices from this development procedure, highlighted in this AMS Guide, can be leveraged by subsequent practitioners to reduce the costs of conducting these activities. If the analysis was successful in better structuring the deployment to increase the efficiency of the ICM by a minimum of five percent, or reduced the risk of a deployment cost overrun of five percent or more, the investment in AMS paid for itself. The partners at the Pioneer Sites felt there was significant value in AMS, which greatly outweighed the analysis costs. Recommended Integrated Corridor Management Analysis, Modeling, and Simulation Approach FIGURE E.1 presents the five major work steps, summarized below, associated with implementing the Integrated ICM AMS methodology. This figure will be repeated throughout this appendix as a roadmap through the work steps. These work steps are based upon a nine-step process developed for the FHWA Traffic Analysis Toolbox Volume III: Guidelines for Applying Traffic Microsimulation Modeling Software. Although the work steps are consistent, they are not identical. resources necessary to conduct the analysis may need to be expanded in order to collect and analyze the necessary data. Using poor-quality or insufficient data will produce inaccurate results that may lead to poor investment decisions. These data requirements have become less of an issue with the advent of private-sector data sources based on information provided by smart phones and in-vehicle GPS devices;

E-4 Broadening Integrated Corridor Management Stakeholders FIGURE E.1. Integrated Corridor Management Analysis, Modeling, and Simulation approach work steps (Office of the Assistant Secretary for Research and Technology and Cambridge Systematics, Inc., 2017). The five ICM AMS work steps are as follows: 1. Develop Analysis Plan The analysis plans developed as part of the ICM AMS methodology provide a valuable tool for communicating the scope of the project—a critical element—indeed, the foundation—of success in an AMS project. A team can expect to spend approximately 15 percent of the AMS time investment on this step, which includes initial planning and scoping and then iterative updates to assumptions, scope, and agreements as the project moves forward. The development of the analysis plans is the primary mechanism for securing a clear and mutual understanding among stakeholders of expectations and assumptions. It may help to identify flaws or technical issues in the ICM Concept of Operations (CONOPS) that may have been otherwise overlooked. Value. The analysis plan confirms not only the stakeholder agreements regarding the scope of the ICM analysis, but also the most appropriate approach to the analysis based on an enhanced understanding of project objectives, the corridor conditions, the ICM strategies being implemented, and the available tools and data. The benefits of completing this work step include a better allocation of resources appropriate to the study objectives; a clear and shared understanding of roles, responsibilities, and expectations among project participants; and the ability of project participants to communicate the project vision effectively to the broader stakeholders. It also helps maintain agreement and project continuity as stakeholders leave positions and new staff comes in mid-stream. Approach. FIGURE E.2 presents an overview of the substeps related to the development of an analysis plan. The output resulting from completion of each substep maps directly to the development of the analysis plan (see example outline shown in TABLE E.1). The reader is encouraged to review the analysis plans of the three Pioneer Sites and the two Demonstration Sites as references.

Analysis Methodology, Tools, and Plan E-5 FIGURE E.2. Overview of Workstep 1: Develop Analysis Plan (Office of the Assistant Secretary for Research and Technology and Cambridge Systematics, Inc.). TABLE E.1. Example outline for Analysis Plan. Example Analysis Plan Outline 1. Introduction and Initial Project Scope: a. Corridor Overview b. Project Background and Guiding Principles c. Project Goals and Objectives d. Process for Developing and Applying the Analysis Plan 2. Corridor Description and Existing Operational Conditions 3. Analysis Scenarios and ICM Strategies 4. Data Needs and Availability 5. Output Performance Measures 6. AMS Tools and Selection Methodology 7. Summary of Analysis Settings 8. Summary of AMS Approach 9. Guidance for Model Calibration 10. Budget, Schedule and Key Responsibilities a. Budget/Resources a. Schedule/Timeframe a. Key Project Roles/Responsibilities Source: Cambridge Systematics, Inc., 2012.

E-6 Broadening Integrated Corridor Management Stakeholders Challenges. Some of the major challenges observed in developing the analysis plan are listed below. ICM strategies often represent new approaches to traffic management in many regions. Unfamiliarity with the strategies may make it more difficult to formulate an analysis approach and identify the likely impacts of the proposed systems. The AMS approach is designed to promote a flexible analysis methodology so that the approach can be continually improved as more information is gained and lessons are learned. However, it is important that deploying agencies define and refine their proposed ICM strategies prior to the completion of the analysis plan so that the AMS approach is appropriate to the final ICM plans. The evaluation of ICM strategies may require the use of unfamiliar performance measures, particularly those specifically focused on non-recurring congestion impacts. In other cases, existing performance measures may not be specific enough to provide for meaningful ICM analysis. Therefore, some additional education may be necessary on the part of AMS managers to inform stakeholders on the importance of these new performance measures. Analysis of “average day” conditions as performed for many typical planning efforts is not sufficient for analysis of ICM deployments. Many ICM strategies are specifically targeted at mitigating non- typical events (e.g., high travel demand, incidents, and inclement weather). Therefore, the analysis must be expanded beyond the “typical day” to measure the potential benefits of ICM properly. Cluster analysis is recommended to identify different operational conditions in the corridor, as well as the frequency of occurrence of these conditions. The most impactful clusters of operational conditions will be analyzed using the AMS tools, and then compared to the “do nothing” alternatives representing the transportation system without ICM turned on (but with pre-ICM corridor management practices in- place). The FHWA’s Traffic Analysis Tools Volume III forthcoming update provides a deeper exploration of understanding why this is critical and provides systematic methods (like cluster analysis) of identifying and modeling a representative range of operational conditions. The USDOT has provided useful guidance on selecting appropriate analysis tools as part of the Traffic Analysis Tools initiative. However, this guidance is intended to steer practitioners to the appropriate general category of analysis tool and model packages, not to specific software vendors. AMS managers should carefully investigate the capabilities of options within the selected category to identify the most appropriate tools and models. In conducting this assessment, AMS managers should seek out guidance from peers who may have conducted similar analysis or used some of the tools under consideration. Further, when selecting and evaluating software, practitioners should keep in mind that software vendors are continuously updating their packages to meet unmet needs and identified deficiencies. What was the best last year may not be as productive this year. Particularly when dealing with ICM, many new advances are in process, so it is helpful to contact vendors to obtain the latest information. Resources. Program managers can expect to allocate approximately 15 percent of the project budget to this step of the initiative. This investment pays dividends in accurately scoping and shaping the AMS effort to achieve the desired objectives, including design of the AMS approach to support longer-term analysis of ICM strategies and corridor performance as the corridor and its needs change. This investment can also support enhanced transportation planning, real-time decision support capabilities, and analysis needs of other related initiatives (i.e., active transportation and demand management or ATDM, etc.). This work step will require the involvement of the full suite of representative stakeholders in ICM from State, regional, and local transportation and planning agencies across the full range of roles, including

Analysis Methodology, Tools, and Plan E-7 freeway, arterial, and transit program and technical managers, engineers, and analysts; transportation planners; and technical modeling and simulation experts. 2. Develop Data Collection Plan and Collect Data The purpose of this work step is to collect the needed data to support the desired analysis cost effectively. In this step, project partners research data needs and availability, identify available data as well as gaps and methods to address those gaps where possible, compile and archive needed data, collect data, and perform quality control on the collected data. This step represents approximately 15 percent of the total work effort for the AMS initiative. Value. The value of successfully completing this work step will be the compilation of relevant and useful datasets and metadata necessary to develop the enhanced models and analysis to be utilized in the subsequent steps, and to provide the foundation for continuous process improvement. The data collection plan will help to ensure that the data collected is of sufficient quality for the needs of the study and will guide the partners in collecting the data using methods that minimize the expenditure of resources on this task. Approach. FIGURE E.3 presents an overview of the substeps related to the development and implementation of the Data Collection Plan. The output from these substeps maps directly to completion of the Data Collection Plan (see FIGURE E.4, Example outline for Data Collection Plan). Subsequent discussions provide additional detail on the recommended conduct of the identified subtasks. FIGURE E.3. Overview of Workstep 2: Develop Data Collection Plan and Collect Data (Office of the Assistant Secretary for Research and Technology and Cambridge Systematics, Inc.).

E-8 Broadening Integrated Corridor Management Stakeholders FIGURE E.4. Example outline for Data Collection Plan (Cambridge Systematics, Inc., 2012). The earlier scoping work for the analysis plan can be used to complete Section 1 of the data collection plan (“Introduction and Background”). Similar to the development of the analysis plan, it is likely that in the course of investigating and collecting the data, opportunities and challenges will be encountered that result in modifications to the data requirements and data collection plan. The data collection plan should remain sufficiently flexible so that lessons learned in the compilation of data sources may be adapted and incorporated as part of the continuous improvement of the AMS effort. Challenges. Due to the innovative nature of many ICM strategies, the collection of relevant data to support AMS offers several unique challenges: • The focus on many ICM strategies on non-recurring congestion may require the development of datasets focused on travel-time reliability and factors influencing non-recurring congestion (e.g., incident occurrence or weather conditions). Automated data sources are often best for collecting the long-term data necessary to assess these non-recurring performance measures; however, many existing automated data collection systems may lack the robustness or reliability to effectively compile relevant data sets. A thorough assessment of the data quality from all sources is recommended to identify any potential problems early on in the process and establish methods to address any deficiencies. • A non-trivial amount of data is needed to represent multiple operational conditions and conduct a cluster analysis. Six to 12 months of data may be required to map different operational conditions adequately including incidents, work zones, weather, etc. • Performance measures necessary for the AMS may require the collection of datasets that are unfamiliar to the managing agency. The AMS manager should seek out peer information on collecting this data for all new or unfamiliar data requirements. • Data for AMS is required to be collected concurrently—collected for the same dates and times across all modes and facilities. This is often different from typical planning data collection efforts that are assembled from data compiled from different dates and times. The demands for concurrent data can require additional effort to coordinate and synchronize the multiple data collection efforts. • Data quality from automated data sources (e.g., roadway loop detectors) may sometimes be insufficient for modeling purposes. Sample datasets should be obtained early in the data collection process and analyzed to assess data quality. The data collection plan should specify data quality procedures and minimal data quality requirements for this purpose. Further, AMS managers should discuss any data Example Data Collection Plan Outline 1. Introductionand Background 2. Data CollectionMethodology 3. Documentation Review 4. Summary of Input Datafor AMS 5. Summary of Data Requirements for Approaches and Strategies 6. Current State of Required Data and Gap Identification 6.1 Arterial-Related Data 6.2 Freeway-Related Data 6.3 Transit-Related Data 7. Summary of Data Collection Methods

Analysis Methodology, Tools, and Plan E-9 quality issues with operations personnel familiar with the data source during the development of the data collection plan in order to understand and anticipate any problems with data source reliability, data accuracy or other condition specific issues (e.g., inaccurate speeds recorded during high volume periods). Revealed traveler preferences as they relate to traveler responses to incidents in the presence or absence of ICM are presented in the May 2016 report titled “Integrated Corridor Management Initiative: Overview of the Dallas Traveler Response Panel Survey.” This report presents findings from the ICM traveler behavior surveys, a set of panel surveys of ICM Demonstration Site corridor users, conducted before and after the deployment of ICM. Resources. Program managers can expect to allocate approximately 15 percent of the project budget to data collection. This investment pays dividends by creating or updating the corridor’s inventory of available data, which provides a foundation for continual process improvement. This work step may take more or less time based on the state and availability of relevant data within the corridor. This work step will require the involvement of the full suite of representative stakeholders in ICM from State, regional, and local transportation and planning agencies across the full range of roles, including freeway, arterial, and transit program and technical managers, engineers, and analysts; transportation planners; and technical modeling and simulation experts. 3. Model Setup and Calibration The purpose of this step is to configure the model(s) and tools to reflect the agreed-upon objectives, scope, and parameters of the AMS and to verify proper model calibration to support accurate results. Model setup and calibration represent approximately 35 percent of the total work effort for the AMS initiative. In this step, the baseline model network is developed, including all relevant transportation facilities and modes. In addition, baseline demand modeling is conducted, and the simulation models are calibrated. This step also includes testing sensitivity of the model to understand limitations of the analysis better. This work step can often be the most time-and resource-demanding of the AMS process. Value. Done correctly, this work step will result in a model with the appropriate robustness and analysis capability to support the analysis in subsequent work steps, and will support risk management for this critical step. Approach. FIGURE E.5 presents an overview of the substeps related to model setup and calibration work step for the ICM AMS effort. The USDOT has several resources that can provide more specific guidance regarding model calibration in general, including Volume III of the FHWA Traffic Analysis Toolbox. It is critical that the datasets be archived and maintained, along with all data dictionaries and supporting information, according to the data maintenance plans defined in the data collection plan. Failure to do so can result in a loss of data and the loss of resource investment in the data collection task.

E-10 Broadening Integrated Corridor Management Stakeholders FIGURE E.5. Overview of Workstep 3: Model Setup and Calibration (Office of the Assistant Secretary for Research and Technology and Cambridge Systematics, Inc.). Calibration criteria should be identified and the selected thresholds documented to establish the benchmarks to be achieved through the process. Documentation provided as part of the FHWA Traffic Analysis Toolbox initiative is useful in establishing these criteria. TABLE E.2 illustrates examples of some of the guideline model calibration criteria established for recurrent congestion used for the ICM Pioneer Sites. TABLE E.2. Example guideline calibration criteria for recurrent congestion. Calibration Criteria and Measures Calibration Acceptance Targets Traffic flows within 15% of observed volumes for links with peak-period volumes greater than 2,000 vph For 85% of cases for links withpeak-period volumes greater than 2,000 vph Sum of all link flows Within 5% of sum of all link counts Travel times within 15% >85% of cases Visual Audits— Individual Link Speeds: Visually Acceptable Speed-Flow Relationship To analyst’s satisfaction1 Visual Audits— Bottlenecks: Visually Acceptable Queuing To analyst’s satisfaction Source: Integrated Corridor Management: U.S. 75 Dallas, Texas—Analysis Plan, FHWA-JPO-10-035, page 37. Note: The ICM AMS work was conducted while the Traffic Analysis Toolbox Volume III guide was being updated. These calibration criteria were used to augment the 2003 guidance prior to the 2017 guidance becoming formalized. For updated calibration methods for ICM (and other) projects, the reader should reference the 2017 guidance. 1 The purpose of visual audits (conducted via field visits to observe/inspect congestion hotspots or specific ICM strategies in place along the corridor) is to provide a balanced understanding of congestion patterns and/or opportunities identified through the course of analysis of the archived data.

Analysis Methodology, Tools, and Plan E-11 For incidents, or non-recurring congestion, the following example guideline model calibration criteria were developed as part of the ICM AMS effort (Note: The ICM AMS work was conducted while the Traffic Analysis Toolbox Volume III guide was being updated. These calibration criteria were used to augment the 2003 guidance prior to the 2017 guidance becoming formalized. For updated calibration methods for ICM (and other) projects, the reader should reference the 2017 guidance): Freeway bottleneck locations. Should be on a modeled segment that is consistent with the location, design, and attributes of the representative roadway section; Duration of incident-related congestion. Duration where observable within 25 percent. Extent of queue propagation. Should be within 20 percent. Diversion flows. Increase in ramp volumes where diversion is expected to take place. Arterial breakdown when incident. Cycle failures or lack of cycle failures. TABLE E.3 presents a snapshot of the guideline transit-related calibration criteria used for the U.S. 75 ICM analysis for the Dallas Pioneer Site corridor. TABLE E.3. Snapshot of guideline transit model validation and calibration criteria for U.S. 75 Integrated Corridor Management—Dallas. Validation Criteria and Measures Acceptance Targets Light-rail station volumes within 20% of observed volumes For 85% of cases Light-rail park-and-ride lots Parked cars in each lot Within 30% Total parked cars for all lots combined Within 20% Source: Integrated Corridor Management: U.S. 75 Dallas, Texas—Analysis Plan, FHWA-JPO-10-035, page 37. Note: The ICM AMS work was conducted while the Traffic Analysis Toolbox Volume III guide was being updated. These calibration criteria were used to augment the 2003 guidance prior to the 2017 guidance becoming formalized. For updated calibration methods for ICM (and other) projects, the reader should reference the 2017 guidance. Challenges. Some challenges that may be encountered during this work step of the AMS are described below. In assessing the model results, the analysts need to weigh the model outputs carefully against the expected outcomes identified in the analysis plan. Where discrepancies exist, further scrutiny is required to assess whether the unexpected outcomes are a result of discrepancies in the model or whether the expected outcomes were not realistic. If the analyst determines that strange model results are a result of model discrepancies, modifications to input parameters may be considered and the alternative rerun; however, it is critical that any modifications to the model inputs be carefully documented and presented in the AMS Report. The AMS is designed to provide for an accurate assessment of ICM impacts on performance measures. However, the interpretation of the analysis results often relies on human assessment. Care should be taken to reduce the risks of introducing bias into the interpretation of results by not giving too much weight to analysis capabilities that are not inherent in the AMS. The analysts should make a significant effort to understand the capabilities and limitations of the models and the datasets fully in order to interpret the results objectively.

E-12 Broadening Integrated Corridor Management Stakeholders The time, staffing, and computing resources required to complete this task can be significant. The analyst managers are encouraged to plan carefully for these resources prior to initiating this task and to provide sufficient flexibility in scheduling these resources to address unforeseen issues that may arise during the work step completion. Resources. Managers are encouraged to reserve approximately 35 percent of their total project budget for Workstep 3: Model Calibration. The quality of the two preceding steps will facilitate greater ease with this work step; however, calibration involves a certain amount of trial and error, which must be accommodated in the AMS budget and planning. The technical modelers will play primary roles in this work step. Managers must have an understanding of the overall calibration methodology and criteria. 4. Alternatives Analysis and Documentation The purpose of this step is to identify the optimum combination of ICM strategies for various operational conditions (e.g., varying roadway congestion and transit demand levels; incident conditions; weather conditions affecting operations; presence of work zones; special events) to support effective ICM. This step includes developing future baseline model networks and trip tables for all operational conditions and conducting the alternatives analysis for all ICM strategies. This step assumes that preliminary strategies/alternatives screening has already been performed using sketch planning or other iterative examinations. If all previous steps have been carefully executed, this step represents approximately 30 percent of the total work effort. consequences) for various hypotheses of interest, prioritization of ICM alternatives, and a quantified understanding of project benefits and costs. The results will inform ICM deployment decisions and can help build support among broader stakeholders for the ICM system. Approach. FIGURE E.6 presents an overview of the substeps related to the alternatives analysis. FIGURE E.6. Overview of Workstep 4: Alternatives Analysis and Documentation (Office of the Assistant Secretary for Research and Technology and Cambridge Systematics, Inc.). Value. The outcomes of this project will include an understanding of predicted effects (including unintended

Analysis Methodology, Tools, and Plan E-13 Challenges. Some challenges that may be encountered during this work step of the AMS are described below. In assessing the model results, the analysts need to weigh the model outputs carefully against the expected outcomes identified in the analysis plan. Where discrepancies exist, further scrutiny is required to assess whether the unexpected outcomes are a result of discrepancies in the model or whether the expected outcomes were not realistic. If the analyst determines that strange model results are a result of model discrepancies, modifications to input parameters may be considered and the alternative rerun; however, it is critical that any modifications to the model inputs be carefully documented and presented in the AMS Report. The AMS is designed to provide for an accurate assessment of ICM impacts on performance measures. However, the interpretation of the analysis results often relies on human assessment. Care should be taken to reduce the risks of introducing bias into the interpretation of results by not giving too much weight to analysis capabilities that are not inherent in the AMS. The analysts should make a significant effort to understand the capabilities and limitations of the models and the datasets fully in order to objectively interpret the results. The time, staffing, and computing resources required to complete this task can be significant. The analyst managers are encouraged to plan carefully for these resources prior to initiating this task and to provide sufficient flexibility in scheduling these resources to address unforeseen issues that may arise during the work step completion. Resources. Workstep 4: Alternatives Analysis and Documentation may represent up to 30 percent of the total work effort for AMS, presuming the preceding steps have been comprehensively implemented. This work step requires intensive involvement of both technical modelers and technical project managers of the ICM and/or ICM AMS initiative who have deep understanding of the operational objectives of the proposed ICM strategies. These individuals work collaboratively to assess the various operational alternatives. A critical dependency for this task is a robust Analysis Plan. 5. Continuous Improvement In this step, practitioners reassess models, model calibrations, and results against observed conditions to validate the AMS approach. Lessons learned are used to improve the process for future deployments, and ongoing performance measurement is used to refine the efficiency of the ICM. This step is ongoing, and consists of the repetition of this process in a manner that reflects and incorporates the data gathering and lessons learned from previous steps. This step represents approximately five percent of the total work effort. Value. The completion of the continuous improvement work step ensures the maintenance of the models and datasets, greatly reducing the costs, enhancing the ease with which future analyses may be performed on the corridor, and improving the effectiveness in which future investment decisions are made. Approach. FIGURE E.7 presents an overview of the subtasks and work steps related to incorporating continuous improvement into the AMS process, as documented in the analysis plan. The figure also provides a summary of where this process relates to other recommended work steps in the AMS.

E-14 Broadening Integrated Corridor Management Stakeholders FIGURE E.7. Overview of Workstep 5: Continuous Improvement (Office of the Assistant Secretary for Research and Technology and Cambridge Systematics, Inc.). Challenges. Some challenges that may be encountered during this work step are summarized below. There is a tendency to want to forego this feedback task once the major analysis tasks have been completed. However, this task is critical to improving AMS. Therefore, the resources necessary to complete this ongoing task should be planned for in the analysis plan, and AMS managers should devote adequate effort to ensure its full and successful completion. Conducting this work step may require a mindset change for some agencies unaccustomed to these activities. Continuous improvement may require changes to agency policies, work habits, and data processes and systems. Resources. This final step is ongoing, and represents approximately five percent of the typical project budget (in most cases this process is beyond the immediate project scope). Implementation of the preceding steps in a systematic fashion positions stakeholders to derive long-term value from ICM AMS. The AMS tools are able to be readily updated and adapted to support other decision support needs to continually improve corridor performance. AMS is not intended to be performed as a one-time, self-contained planning process. Instead, as shown in FIGURE E.8. AMS is intended to be an ongoing, continuously improving process designed to assist practitioners in envisioning, designing, and refining ICM strategies.

Analysis Methodology, Tools, and Plan E-15 FIGURE E.8. Continuous process improvement for Integrated Corridor Management (Karl Wunderlich, Noblis, 2010). In this continual cycle of trial and improvement, analytical capital is accumulated. This incrementally increasing knowledge base tends to be self-fulfilling because as improvements are discovered and implemented among the performance measures, modeling and simulation, and archived data processes and systems, further enhancements are encouraged by the resulting improvements in analysis capabilities and greater trust in the model processes and results.