Planning for Transportation Systems Management and Operations within Subareas – A Desk Reference

CHAPTER 5. TOOLBOX FOR EFFECTIVE TRANSPORTATION SYSTEMS MANAGEMENT AND OPERATIONS PLANNING

There are a variety of tools that can support transportation systems management and operations (TSMO) planning within subareas, and many of them have already been discussed prior to this chapter, including analytical tools and simulation models, the regional intelligent transportation system (ITS) architecture, and archived operations data. (Note: The word "tools" is used in this chapter in the broadest sense—anything that can be used to support and enhance TSMO planning on a subarea.) This chapter offers readers a "toolbox" of analysis instruments and planning techniques that can be applied when planning for TSMO within subareas. For several of the tools described, there is at least one additional Federal Highway Administration (FHWA) guide that can give readers a much greater understanding of how the tool may be applied. This chapter begins with two planning techniques and then moves into quick reference sheet-style descriptions of common types of analysis tools. Following the quick reference sheets are overviews of several specific applications that planners and operators can use to address analysis needs directly while planning for TSMO within subareas.

SCENARIO PLANNING FOR TRANSPORTATION SYSTEMS MANAGEMENT AND OPERATIONS WITHIN SUBAREAS

Scenario planning is an important enhancement to planning for TSMO within a subarea. It can be used to incorporate the consideration of factors that are difficult to predict, such as evolving technology, climate change, shifting traveler behavior, financial uncertainty, failing infrastructure, natural and man-made events, and other unknowns into planning and programming decisions. Scenario planning supports the exploration and consideration of different future conditions in a subarea.

Scenario planning is an approach to strategic planning that uses alternate narratives of plausible futures (or future states) to play out decisions in an effort to make more informed choices and create plans for the future. It engages participants in considering the "what ifs" of tomorrow and whether those are desirable or undesirable outcomes. The simple task of imagining a different future can help to challenge the status quo and encourage creative thinking, which ultimately can lead to the development of more thoughtful and resilient plans. Scenarios are developed to enable participants to test out possible decisions, analyze their impacts given the conditions in each scenario, and come to agreement on a preferred course of action.

Scenario planning follows many of the same planning activities as described in Chapter 3, beginning with scoping the effort, examining current conditions and trends, and then identifying goals and objectives. In scenario planning, the leaders and stakeholders would then develop multiple scenarios or descriptions of possible futures, identify the strategies needed to realize each of the scenarios, and then analyze the impacts of each scenario against reaching their objectives. The scenario planning approach to TSMO is shown in Figure 20.

Generally, there are three types of scenario planning that reflect the different conditions and purposes for which scenario planning may be used. For example, scenario planning for TSMO within a subarea may be used to identify the most effective package of TSMO strategies given an expected change in conditions on the subarea (trend-based type). Alternatively, scenario planning may be used to build consensus on operations objectives by examining multiple desired future conditions and the strategies needed to support those conditions (normative type). Finally, scenario planning can be used to examine different scenarios in response to uncontrollable or unknown future conditions (e.g., to better understand the impacts of global trade changes, extreme weather, etc.). The purpose of this is to guide stakeholders in identifying policies, plans, and strategies that can work best under all extreme conditions (exploratory type).

Additional information on how to use scenario planning to advance TSMO can be found in FHWA's Advancing Transportation Systems Management and Operations Through Scenario Planning.⁸⁷

USE OF ARCHIVED OPERATIONS DATA

Archived operations data is a critical tool in an objectives-driven, performance-based planning approach to TSMO within subareas. Archived operations data is information that is collected and stored in support of day-to-day efforts to monitor and manage the transportation system. Archived operations data can include traffic, transit, bike, pedestrian, construction, and weather information that is usually collected in real time by ITS infrastructure, such as in-pavement inductive loop detectors, radar detectors, remote traffic microwave sensors, Bluetooth, and EZPass or other unique identification tag readers. It also includes incident or event information entered into electronic logs by transportation or public safety personnel. Transportation planners at the State, metropolitan, and local level are finding that, with archived operations data, they are able to do more, be more accurate, and solve more problems than ever before—relying less on assumptions and modeled data and making more effective, less costly decisions.

There are several advantages to having archived operations data available, including:

• Providing a more accurate picture of system performance.
• Opening up new types of analyses to support the planning process.
• Enabling more advanced modeling.

The following are examples of significant uses for archived operations data in planning for TSMO within subareas:

• Monitoring and evaluating system performance in support of identifying performance issues/needs, project prioritization, and reporting. Archived travel time data forms the basis for computing a wide variety of congestion, reliability, and freight performance measures.
• Setting performance targets. Archived data provides information on past trends that are useful in establishing targets.
• Evaluation of completed projects. A key component of performance-based planning is the ability to conduct evaluations of completed projects and to use the results to make more informed investment decisions in the future.
• Trip-based mobility monitoring and accessibility. Although archived origin-destination travel time data is just becoming available, it is expected to become more prevalent as technology evolves. Origin-destination data makes it possible to monitor the performance of trips taken by travelers.

FHWA has produced a desk reference (Use of Archived Operations Data in Planning) on applying archived operations data to planning aimed toward TSMO planners and their planning partners. This desk reference raises planners' awareness of the opportunities afforded through archived operations data and provides guidance on how to take advantage of that data to expand and improve planning practices⁸⁹ It also identifies new and innovative applications for this data in planning. The desk reference is intended to help planners and their operations data partners overcome the barriers to obtaining and using data.

ANALYSIS TOOLS AVAILABLE FOR TRANSPORTATION SYSTEMS MANAGEMENT AND OPERATIONS PLANNING WITHIN SUBAREAS

Below are the quick reference sheets for several types of analysis tools that can be applied for TSMO planning within subareas. The types of analysis tools covered are travel demand models, sketch planning tools, analytic/deterministic tools, simulation tools, and dynamic traffic assignment (DTA) methods.

Travel Demand Models

Description	Travel demand models are widely used to compare or screen alternatives by using origin-destination (O-D) patterns, demand-to-capacity ratios, differences in percent volumes, and rough estimates of travel times. These models consider land use, demographics, mode choice, and the transportation system (roadway and transit).
Examples	Types of models: Three-step models (no mode choice). Four-step models. Activity-based models. Mesoscale models. Software: TransCAD, Emme, and Cube.
Planning for Operations Uses for Subareas	Supply data (e.g., travel forecast inputs) to sketch-planning tools, simulation models, and post-processors that can analyze subarea operations strategies. Use traffic O-D patterns or volumes for input into subarea simulation models. Provide changes in peak-hour turning volumes at major intersections and freeway ramp volumes through refined (subarea) travel demand models. Extract tables with O-D for trips in a focus area as required input for microscopic subarea simulation models. Screen and evaluate subarea strategies. Assess mode choice and travel pattern/volume impacts. Capture linked trips (e.g., home-to-work-to-shopping-to-home), smart growth, walk/bike trips for parcel-level models, and more accurate O-D estimates for use as inputs to simulation models.
Advantages	Validates models available for most metropolitan areas. Evaluates subarea impacts. Is consistent with current planning practices. Is capable of estimating mode choice and travel pattern change reductions. due to transit and smart growth.
Challenges	Limited ability to analyze operational strategies. High initial costs. Typical travel day does not capture incident, weather, work zones, and special event conditions.

Sketch Planning Tools

Description	Sketch-planning tools provide quick order-of-magnitude estimates with minimal input data (e.g., traffic volumes and speeds) in support of preliminary screening assessments. These tools are appropriate early in the planning process when prioritizing large numbers of projects or strategies for more detailed evaluation. Tools are often spreadsheets or simple databases that are based on built-in assumptions of impacts and benefits for various strategies. Data from sketch-planning tools, such as the Florida ITS Evaluation Tool (FITSEVAL), can be integrated with travel demand model data to provide analysis of operational strategies.
Examples	Tool for Operations Benefit Cost Analysis (TOPS-BC). ITS Benefit/Cost Database. California Life-Cycle Benefit/Cost Analysis Model (Cal-B/C). Florida ITS Evaluation Tool (FITSEVAL). QuickZone(work zone analysis tool). Results from other subarea before-and-after studies.
Planning for Operations Uses for Subareas	Evaluate policy-based and subarea transportation systems management and operations (TSMO) strategies. Screen a large number of potential TSMO strategies and obtain a general idea of whether a strategy is worth investigating further. Generate expected impacts of TSMO projects that can be compared with other potential investments, such as traditional roadway capacity improvements.
Advantages	Low cost. Fast analysis times. Uses readily accessible data. View of the "big picture." Some tools expressly for evaluating policy-based or subarea strategies. May be integrated with travel demand model.
Challenges	Limited in scope, robustness, and presentation capabilities. Results constrained by quality of input data and built-in assumptions of impacts. Not always transferable between agencies.

Analytical/Deterministic Tools

Description	Most analytical/deterministic tools implement the procedures of the Highway Capacity Manual. The following summarize the Highway Capacity Manual procedures: Closed-form: A practitioner inputs data and parameters and, after a sequence of analytical steps, the Highway Capacity Manual procedures produce a single answer. Macroscopic: Input and output deal with average performance during a 15-minute or a 1-hour analytical period. Deterministic: Any given set of inputs will always yield the same answer Static: Predict average operating conditions over a fixed time period and do not deal with transitions in operations from one system state to another. Analytical/deterministic tools quickly predict capacity, density, speed, delay, and queuing on a variety of transportation facilities.
Examples	Highway Capacity Software (HCS). Traffix.
Planning for Operations Uses for Subareas	Analyze the performance of isolated or small-scale transportation facilities. Examine impacts under different demand conditions. Assess a range of traffic control strategies (e.g., uncontrolled, stop- controlled, signalized).
Advantages	Predicts impacts for isolated or small-scale transportation facilities. Is widely accepted. Provides repeatable results.
Challenges	Limited ability to assess many transportation systems management and operations (TSMO) strategies. Limited ability to analyze broader subarea network or system effects. Limited output of performance measures.

Simulation Tools

Description	Simulation tools use a variety of formulas and algorithms to simulate travel behavior to analyze operations of traffic and transit to conduct needs assessments, alternatives analysis, environmental impact studies, and operations planning. These tools may be deterministic or incorporate stochastic sampling or perturbation. Simulation tools can be classified as: Macroscopic: Simulates average flow, speed, and density on a segment-by-segment basis. Mesoscopic: Simulates individual vehicles based on average segment speed and density. Microscopic: Simulates detailed movement of individual vehicles throughout the network. Multi-resolution: combines tools of different scales (e.g., mesoscopic and microscopic) to identify trade-offs between computational efficiency and modeling accuracy for critical subareas.
Examples	Macroscopic: PASSER, TSIS-CORSIM(includes TRANSYT-7F), and VISTA. Mesoscopic: DYNASMART-P, DynusT, DTALite, DynaMIT, TransModeler, TRANSIMS, Aimsun, and Dynameq. Microscopic: TSIS-CORSIM, Paramics, VISSIM, TransModeler, and Aimsun.
Planning for Operations Uses for Subareas	Evaluate a range of improvements and strategies at subarea levels. Conduct sensitivity testing to reflect variability in traffic demands or incident severity. Refine project scope and design. Support environmental assessment.
Advantages	Simulates operations strategies to varying degrees. Offers extensive and comprehensive model outputs. Incorporates traffic variations as observed in the field. Provides dynamic analysis of incidents and real-time diversion patterns when mesoscopic models are used. Analyze complex conditions and multi-modal interaction. Offer visual presentation opportunities.
Challenges	Expertise needed to develop and apply models. Demanding data and computing requirements. Calibration may be time consuming. Extensive outputs may require development of separate post-processing tools.

Dynamic Traffic Assignment

Description	DTA is a simulation tool that assigns vehicles to paths based on traffic conditions instead of pre-defined routes using origin-destination data and link path travel time equilibrium. Simulated vehicles can adapt to prevailing conditions, change start times, choose alternative routes, or change modes. DTA often involves a combination of model types representing multi- resolution modeling. The following are requirements for DTA: Travel demand model (highly recommended). Data for development and calibration. Origin-destination estimation technique. Transportation modeling software with DTA capabilities. Appropriate transportation modeling skill.
Examples	DYNASMART-P. DynusT. DTALite DynaMIT. Dynameq.
Planning for Operations Uses for Subareas	Simulate the impact of incidents/events. Evaluate operational strategies that are likely to induce a temporal or spatial pattern shift of traffic. Estimate travel behavior from various demand/supply changes and interactions. Conduct analyses involving incidents, construction work zones, active transportation and demand management (ATDM) strategies, congestion pricing, etc.
Advantages	More realism in estimating traveler response and therefore operations. Wider range of strategies can be more accurately tested.
Challenges	Is resource intensive. Requires skill sets of both travel demand modeling and simulation modeling.

WEATHER-RESPONSIVE TRAFFIC MANAGEMENT STRATEGIES AND TOOLS

Application to Planning for Transportation Systems Management and Operations within Subareas

Inclement weather is known to have disruptive impacts on traffic operations and system performance and may temporarily alter travel demand. Neglecting these impacts and changes may lead to decreased performance of the transportation system. Through FHWA's Road Weather Management Program, predictive weather-responsive traffic system management decision support capabilities have been developed and tested, including the weather-sensitive Traffic Estimation and Prediction System (TrEPS).⁹⁰

Within the TrEPS model is DYNASMART-X, a real-time system that continuously interacts with loop detectors, roadside sensors, and vehicle probes to provide real-time estimates of traffic conditions, network flow patterns, and routing information. TrEPS allows weather-responsive traffic management (WRTM) applications to be used in network modeling and simulation tools and demonstrates the potential of WRTM in evaluating and developing strategies for urban areas and subareas as part of the routine functions of planning and operating agencies. In addition, FHWA is trying to improve integrated modeling for road condition prediction (e.g., better integration with weather forecasts/other traffic events, and improved interfacing with existing systems and TMC databases) by enhancing TrEPS functions.⁹¹

Samples of Use

FHWA used the TrEPS model, calibrated for the Salt Lake City region, to implement and evaluate weather-responsive traffic signal timing in the Riverdale corridor in Ogden, Utah. The goal was to optimize signal timing in a subarea to reduce the impacts of inclement weather events and to prevent or alleviate congestion. Real-time simulation of the traffic network forms the basis of the prediction capability. It fuses historical data with sensor information, and uses a description of how traffic behaves in networks to predict future conditions and develop control measures accordingly. The estimated state of the network and predicted future states are given in terms of flows, travel times, and other time-varying performance characteristics on the various components of the network. These are used in the on-line generation and real-time evaluation of coordinated signal timing along main arterials, for diversion paths, and for weather-related interventions.

When estimating and predicting traffic, TrEPS uses weather data, which allows traffic signal control intervention to be selected in a systematic and continuous process. Signal control intervention is linked to the TrEPS-predicted conditions, including weather conditions and traffic demand observed via roadway and signal sensors. The signal control interventions are linked to the TrEPS-predicted conditions that reflect weather conditions and traffic demand. Real-time traffic data feeds used as the basis for traffic estimation and prediction are obtained directly from sensors that are driving the vehicle-actuated operation of the signals. An important enabler is a scenario manager that allows relatively easy and timely selection of coordination plans given the predicted states, effectively communicated to the system operator. It is an essential link between traffic estimation and prediction and the traffic signal control decisions.

Figure 21 illustrates the overall architecture of the decision support system. The system supports the TMC signal systems operator's decision making in deploying alternative signal timing plans during a weather event by integrating three components—TrEPS, Scenario Manager, and Scenario Library—into the TMC's signal operations. The Scenario Manager is a scenario generation and management tool that serves as an interface between the TrEPS real-time simulation engine and a human decision maker. It facilitates the process of developing and preparing input scenarios for the TrEPS model and the exchange of information between TrEPS and TMC operators. Deploying a particular signal plan involves setting a large number of control parameters for individual traffic signals. From a practical point of view, it often is not feasible for TMC operators to create a new plan whenever parameter adjustments are needed. Therefore, TMC operators commonly maintain a manageable number of pre-defined "canned" action sets (i.e., a Scenario Library), each of which defines all the parameters and coordination settings associated with each timing plan, and simply switch between these existing plans during traffic signal operation. The Scenario Library approach is introduced to aid this type of operation (see Figure 22).⁹²

Advantages

The potential advantages of TrEPS include:

• Integration of weather effects (from the perspectives of both demand and supply) with traffic estimation and predictions, the results of which form a basis for developing traffic management strategies.
• The use of available real-time measurements to improve the quality of its estimation and future prediction, and thus provide a reliable basis for improved traffic management decisions that anticipate future conditions.
• The use of a Scenario Manager and Scenario Library to simplify and facilitate the human operator's interaction with the predictive system.
• Flexibility in integration of other traffic events (e.g., incidents and work zones) into the analysis framework.
• Flexibility in integration of other operational strategies (e.g., incorporating transit-related and multi-modal capabilities in the interest of greater metropolitan mobility; and integration of fleet routing functionality—for snow removal equipment, preventive sanding, freeze- melting agent spreading, and other logistical processes).

Challenges

While considerable progress has been accomplished to date on the successful deployment of weather responsive TrEPS, there remain several challenges with using the tool:

• Traffic models need to be better integrated with weather forecast systems, and the integration between them (e.g., relationships between rain intensity and roadway capacity reduction) needs to be further studied and quantified.
• Integration with current TMC systems (e.g., interfacing with their database) needs to be strengthened.
• Reliable model performance requires advanced model calibration with large amounts of data, and the calibration depends on data availability, which varies at different TMCs. Therefore, additional real-time data sources (e.g., mobile data and social media) need to be considered in the estimation and prediction process.

TOOL FOR OPERATIONS BENEFIT COST ANALYSIS

The Tool for Operations Benefit Cost Analysis (TOPS-BC) offers a means to determine whether investment in a given TSMO strategy is justifiable in comparison to investment in a traditional capital infrastructure project. The tool was created by FHWA as a sketch-planning benefit-cost analysis tool to support preliminary screening and initial prioritization of TSMO strategies. The TOPS-BC tool has four key functions:

• Allows users to look up the expected range of TSMO strategy impacts based on a database of observed impacts in other areas.
• Offers guidance and a selection tool for users to identify appropriate benefit-cost methods and tools based on the input needs of their analysis.
• Supports the ability to estimate life-cycle costs of a wide range of TSMO strategies.
• Enables users to estimate benefits using a spreadsheet-based sketch-planning approach and the comparison with estimated strategy costs.

As a sketch-planning tool, TOPS-BC allows users to quickly understand typical benefits for a range of TSMO strategies and then estimate the benefit-cost ratios for each of those TSMO strategies. The tool also provides a suggested list of analysis tools whose use depends on user selected criteria, such as the level of confidence required, which TSMO strategies are being investigated, key measures of effectiveness, and a few other filters.

The TOPS B-C tool is built on a Microsoft Excel platform and can be downloaded from FHWA's Planning for Operations website at: https://ops.fhwa.dot.gov/plan4ops/topsbctool/index.htm. TOPS-BC is a companion resource to FHWA's Operations Benefit/Cost Desk Reference.

Application to Planning for Transportation Systems Management and Operations within Subareas

TOPS B-C is a useful tool for analyzing TSMO strategies identified in subarea planning. The strategies included in TOPS B-C are commonly applied in subareas. Table 4 lists those TSMO strategies included in the TOPS-BC tool and indicates whether typical impacts or benefits are provided for the strategy, as well as the availability of more detailed calculation tools for costs and benefits.

Table 4. Strategies included in the Tool for Operations Benefit-Cost Analysis.

TSMO Category	TSMO Strategy	Typical Impacts	Cost	Benefit
Traveler Information	Dynamic message signs.	Yes	Yes	Yes
	Highway advisory radio.	Yes	Yes	Yes
	Pre-trip traveler information.	Yes	Yes	Yes
	Other traveler information strategies.	Yes	No	No
Traffic Signal Coordination Systems	Preset timing.	Yes	Yes	Yes
	Traffic actuated.	Yes	Yes	Yes
	Central control.	Yes	Yes	Yes
	Transit signal priority.	Yes	Yes	No
	Emergency signal priority.	Yes	No	No
Ramp Metering Systems	Central control.	Yes	Yes	Yes
	Traffic actuated.	Yes	Yes	Yes
	Preset timing.	Yes	Yes	Yes
Other Freeway Systems	Traffic incident management.	Yes	Yes	Yes
Advanced Traffic Demand Management	Speed harmonization.	No	Yes	Yes
	Employer-based traveler demand management.	No	Yes	No
	Hard shoulder running.	Yes	Yes	Yes
	High-occupancy toll lanes.	Yes	Yes	Yes
	Road weather management.	Yes	Yes	Yes
	Work zone.	Yes	Yes	Yes
	Advanced public transit systems.	Yes	No	No
	Congestion pricing.	Yes	No	No
Supporting Strategies	Traffic management center.	No	Yes	No
	Loop detection.	No	Yes	No
	Closed circuit television cameras.	No	Yes	No

Samples of Use

As noted above, the tool exists as a Microsoft Excel spreadsheet with several tabs and color coded cells that clearly identify where the user needs to provide information but also allows the user to modify the spreadsheet as needed.

TOPS-BC calculates an annualized cost for each strategy that incorporates the useful life of the equipment, the replacement cost, and the annual operations and maintenance cost. The net present value of implementing the strategy also is provided, and while default values for the discount rate and time horizon are provided, the user can change those values.

The cost components for each TSMO strategy are broken down into two categories: the one-time costs to create the backbone structure for the strategy (e.g., software and system integration), and the incremental cost of each additional installation (e.g., additional loops, weather stations, and dynamic message signs). Default costs are included in the spreadsheet for all of the cost components. The user simply needs to enter the number of infrastructure deployments and the number of incremental deployments.

The annual benefits calculated by TOPS-BC focus on travel time savings for both recurring and non-recurring congestion, energy/fuel savings, and savings due to reduced crashes. A tab marked "Parameters" includes all of the assumptions used to calculate the benefits, such as:

• Cost of fuel.
• Fuel economy of autos and trucks.
• Cost of hourly travel for autos and trucks.
• Typical percent of trucks on the facility.
• Cost of crashes by severity.
• Typical emissions.
• Typical crash rates by facilities.
• Speed-flow relationships.
• Typical incident delay factors.

If local information is known, in particular the percentage of trucks on the facility and crash rates on the facility by severity, those can be modified to provide a more accurate assessment of benefits. However, if local factors are not known, the default values make the tool ready to use for an approximation of the benefit for the desired TSMO countermeasure.

As with the cost component, each strategy has its own tab to calculate benefits. Again, color-coded cells are used to help the user identify where input is required. A basic benefit analysis requires minimal input from the users. For example, to calculate the benefits for dynamic message signs, the user is required to provide three pieces of information:

• Length of the analysis period.
• Type of traveler information (three options are provided on a pull-down menu).
• Traffic volume passing the sign location(s) during the period of analysis.

There are additional categories where default values are provided, or the user can override those values when location-specific information is known. For example, the ramp meter benefits assessment assumes a freeway free flow speed of 55 miles per hour and a ramp free flow speed of 35 miles per hour. Both of those values can be overridden if local data are known.

In addition to the benefit tabs for each strategy, the tool contains a generic link-based analysis tab that can be used to enter benefits related to a TSMO strategy not specifically identified. The TOPS-BC tool also includes a summary tab that allows the user to select some or all of the strategies for a total benefit-cost summary.

Advantages

The following are advantages of the TOPS B-C tool:

• The tool provides information that can be used in conjunction with benefit-cost analyses for capital infrastructure, which can be useful when comparing TSMO and capital infrastructure projects.
• It is customizable; therefore, if better data is available, the user can easily modify the spreadsheet with project-specific costs or add components.

Challenges from Training

The right-of-way acquisition is an important component that is not captured in the cost-estimating tool.⁹⁵