Advancing Transportation Systems Management and Operations Through Scenario Planning

Section 4: Opportunities for Scenario Planning to Advance Transportation Systems Management and Operations

Planning for transportation systems management and operations (TSMO) occurs both formally and informally at the statewide, regional, subarea, local, corridor, project, and multi-state level. Scenario planning is a tool that planners and operators can apply in all of those contexts to prepare for uncertainty, resolve competing visions, create more robust stakeholder engagement opportunities, and better align an area's transportation goals with TSMO strategies. As previously noted, the type of scenario planning to be applied depends on the focal questions and desired outcomes of the stakeholders. The purpose of this section is to explore the many opportunities available to use each type of scenario planning to advance TSMO. This section describes how scenario planning for TSMO can be applied at the metropolitan, statewide, and corridor levels as well as how it can be applied to TSMO planning motivated by possible future events or emerging trends.

The following sections highlight some of the opportunities to improve TSMO through the use of scenario planning.

Regional Opportunities

At the regional level, planning for TSMO is often led by the metropolitan planning organization (MPO), which convenes a group of TSMO stakeholders to advance TSMO in the region. Typically, planning occurs in coordination with the development of the metropolitan transportation plan as a means of including TSMO priorities and strategies into the overall metropolitan transportation plan (MTP) and including TSMO programs and projects in the transportation improvement program (TIP). Planning for TSMO at the regional level may also be led by a coalition of operating agencies or a State department of transportation (DOT) district. For the purposes of this primer, a region does not need to coincide with an MPO boundary, but instead can be any multi-jurisdictional area as defined by the TSMO partners. A regional operations plan, intelligent transportation systems (ITS) strategic plan, or regional concept for transportation operations (RCTO)²⁷ are all products that may be developed as a result of planning for TSMO at the regional level. The opportunity to use scenario planning to advance TSMO at the regional level exists in the development of these products as well as in the process of planning for TSMO as an integrated component of the overarching metropolitan transportation planning process.

Developing Operations Objectives for a Regional Operations Plan

A regional operations plan is a generic term for a multi-jurisdictional, multi-agency plan that describes what the region's stakeholders have agreed to achieve in terms of operational performance of the transportation system (or element) and how they will reach those goals and objectives. This includes regional concepts for transportation operations and many ITS strategic plans. Scenario planning can be used to identify and reach consensus on many of the elements of a regional operations plan. For example, by applying a normative type of scenario planning, the stakeholders explore and decide on a preferred set of operations objectives. If there were differing ideas of which operations objectives should be selected to guide their work toward advancing TSMO in their region, the stakeholders could build scenarios that portray how the future transportation system would function if each set of operations objectives was reached. They would then look at what kinds of TSMO strategies would be necessary for those scenarios to be realized and analyze and compare the implications of those scenarios. Using scenarios will lead the stakeholders through a discussion of their priorities and whether reaching a given set of operations objectives is feasible. The operations objectives developed for the regional operations plan can be used as input to the MTP's goals and objectives.

Table 5 provides sample operations objectives that can be tailored for use in a scenario planning exercise for a regional operations plan or many other TSMO planning activities.

Table 5. Sample Operations Objectives for Use in Scenario Planning.

System Efficiency
Vehicle Miles Traveled	Reduce vehicle miles traveled per capita by X percent by year Y.
Trip Connectivity	Reduce door-to-door trip time by X percent by year Y.
Duration of Congestion	Reduce the daily hours of recurring congestion on major highways from X to Y by year Z.
Energy Consumption	Reduce total energy consumption per capita for transportation by X percent by year Y. Reduce total fuel consumption per capita for transportation by X percent by year Y. Reduce excess fuel consumed due to congestion by X percent by 2020.
System Reliability
Non-Recurring Delay	Reduce total person hours of delay (or travel time delay per capita) by time period (peak, off-peak) caused by: (Option 1) scheduled events, work zones, or system maintenance by X hours in Y years. (Option 2) unscheduled disruptions to travel. (Option 3) all transient events such as traffic incidents, special events, and work zones.
Travel Time Buffer Index	Decrease the buffer index for (specific travel routes) by X percent over the next Y years. Decrease the average buffer index for (multiple routes or trips) by X percent over Y years. Reduce the average buffer time needed to arrive on-time for 95 percent of trips on (specified routes) by X minutes over Y years.
Planning Time Index	Reduce the average planning time index for (specific routes in region) by X (no units) over the next Y years. Reduce the average planning time for (specific routes in region) by X minutes over the next Y years.
Travel Time 95th/90th Percentile	Reduce the average of the 90th (or 95th) percentile travel times for (a group of specific travel routes or trips in the region) by X minutes in Y years. Reduce the 90th (or 95th) percentile travel times for each route selected by X percent over Y years.
Variability	Reduce the variability of travel time on specified routes by X percent during peak and off-peak periods by year Y.
Transit On-time Performance	Improve average on-time performance for specified transit routes/facilities by X percent within Y years.
System Options
Mode Share	Reduce per capita single-occupancy vehicle (SOV) commute trip rate by X percent in Y years. Increase alternative (non-SOV) mode share for all trips by X percent within the next Y years. Increase active (bicycle/pedestrian) mode share by X percent by year Y. Reduce SOV vehicle trips by X percent through travel demand management strategies (e.g., employer or residential rideshare) by year Y. Achieve X percent alternative (non-SOV) mode share in transit station communities (or other destinations) by year Y.

Developing the Approach for a Regional Concept for Transportation Operations

Alternatively, scenario planning can be applied to help identify the "how" of an operations plan or RCTO including the TSMO strategies. For example, the RCTO developers could use scenario planning to identify a set of TSMO strategies that would be most effective given uncertainty about whether and exactly where a light rail system will be built in the next 10 years in the region. An exploratory type of scenario planning would facilitate a discussion about how the region's transportation system could function depending on the presence or absence of a new light rail system and which TSMO strategies would be most effective in all possible scenarios.

A predictive approach to scenario planning could also be used during the development of an RCTO approach. Stakeholders could use scenario planning to help examine how effective different TSMO strategies might be relative to assumptions concerning available funding or availability of new forms of data and real-time monitoring. This predictive approach to scenario planning assumes the major variables such as travel demand and travel behavior follow a predictable pattern or forecast, but there may be variability in funding or data availability. The purpose of this scenario planning exercise would be to identify which TSMO strategies will work best in managing system performance to achieve desirable goals over the RCTO's time horizon.

Identifying Packages of Transportation Investments Including Operations for a Metropolitan Transportation Plan

Scenario planning could be used during the development of the MTP in response to a region's desire to look at different alternatives for growth and development relative to achieving a distinct vision or specific goals, like reducing emissions or increasing transportation choices. Through a normative typology for scenario planning, the region's stakeholders would develop multiple scenarios, including TSMO strategies at the system-level, based on different assumptions concerning future development patterns (land use) and packages of transportation capital investments. TSMO stakeholders would be brought in to identify specific TSMO strategies that could support each scenario. The scenarios would be evaluated and considered by a broad stakeholder group for the purpose of achieving specific goals illustrated by specific performance measures, like reducing travel time for autos and transit or incorporating TDM strategies to reduce overall travel demand.

The participation of TSMO stakeholders and consideration of TSMO strategies at the long-term planning stage can lead to early identification of new data gathering and real-time system performance monitoring needs. These early conversations about scenarios also lay the groundwork for the more detailed planning required for a specific regional operations plan that will likely focus on shorter time horizons, like 3 to 10 years. The link between the long-range and more intermediate-range regional operations plan development could involve incorporating new performance measures.

During both the long-range and shorter term planning processes, TSMO scenario planning benefits from the inclusion of a wide range of public and stakeholder representatives. This could include land-use planners, transit agency representatives, bicycle and pedestrian interests, councils on aging, private technology developers and providers, system operators, freight and goods movement professionals, and other parties with a role or interest in transportation system design and performance. The purpose of including this broad constituency group is to ensure the cross pollination of ideas in identifying goals, developing scenarios, and discussing the tradeoffs of different paths for the future. It also benefits all parties to better understand the role TSMO strategies play in overall system performance and how they can continue to evolve in response to changing user preferences and data availability. Incorporating TSMO strategy considerations as part of larger transportation planning efforts also helps to build broad stakeholder awareness and understanding of TSMO needs and priorities, which in turn can help with early identification and support for TSMO funding.

Statewide Opportunities

At the statewide level, operations stakeholders typically led by the State DOT conduct planning activities and make multiple planning and investment decisions related to TSMO that can benefit from scenario planning. Just as regions develop plans for managing and operating the transportation system at a regional scale, States develop operations plans to address operations across the State. The statewide operations plans may be higher level documents that establish policies, goals, and operations objectives that provide guidance to their districts or metropolitan regions as they develop more detailed plans for operations. The statewide operations plans may also include plans for investments in TSMO projects that have statewide significance. State DOTs also incorporate planning for investments in TSMO in their overall transportation system investment planning process. This is illustrated in the text box below, which describes Minnesota DOT's scenario-based development of its 20-year State Highway Investment Plan.

Each of these statewide operations planning efforts seeks to answer questions that may be most effectively answered through a scenario planning approach. The following are types of questions that scenario planning can address in these TSMO planning efforts:

• What is the desired vision for statewide highway operations given several opposing priorities?
• What statewide investments for operations are needed to sustain a safe, efficient highway system with a significant increase projected for truck traffic (or other known trend that may impact the transportation systems operational performance)?
• What policies and TSMO investment areas should be targeted given uncertainty in climate change impacts (or future transportation technologies, budgets, etc.)?

There are several other TSMO-focused planning activities that occur at the state level. A few examples that could benefit from scenario planning are given below.

Transportation Management Center (TMC) Planning

Plans for the short-, mid-, and long-term management and operation of a TMC require planners to assess future staffing needs and make decisions about technology use and deployment as well as the level of service that can be provided to the public given funding constraints. Scenario planning can be particularly effective in addressing technology investment decisions given the uncertainty in new technology developments, costs, impacts on staffing needs, and whether the new technology will work with current technology. There is also uncertainty in projecting the demand for TMC services given the potential strains on the system by an increase in extreme weather events and the role of the TMC as vehicle automation becomes prevalent. By using exploratory scenario planning, TMC managers and stakeholders can examine alternative futures and determine how best to prepare the TMC for those potential realities. In addition, managers and stakeholders can look at different portfolios of TSMO strategies, staffing levels, and technology and examine the impacts of each portfolio against the desired performance expectations for the TMC and the transportation system.

Developing Work Zone Management Plans

A transportation management plan (TMP) for a work zone contains the work zone management strategies–such as travel demand management, signal retiming, and traffic incident management–that will be used for the project. For significant projects, the strategies must include both public information and transportation operations components to address the impacts around the work zone. TMP developers can use the trend-based type of scenario planning to discuss with stakeholders the impacts of a few different approaches to managing a major upcoming work zone and develop a preferred scenario based on thorough stakeholder input and analysis of impacts.

Developing a Statewide Freight Mobility Plan

Many States now have freight mobility plans to sustain and improve connections among markets within the State and connections from the State to national and international markets. These plans typically define policies and investments to improve intermodal freight mobility to increase the trade-related jobs and income for the State's workers and businesses.^{32, 33} Freight planning is a significant opportunity for the use of scenario planning because of the large number of uncontrollable and often uncertain driving factors that influence the success or failure of decisions regarding freight investment. In addition, freight involves a large number of stakeholders that need to be engaged in the planning effort and support the outcome. Through scenario planning, multiple perspectives can be brought to the forefront for analysis and discussion.

Corridor Opportunities

A corridor is a linear system of multimodal facilities and adjacent development. Corridors range in length from a few miles in an urban location to hundreds of miles for state or multi-state corridors. Given the diversity of corridors, scenario planning at that level can take many forms.

Similar to the regional approach, it will likely be driven by either a normative or predictive approach and may go through multiple iterations. In the normative approach, corridor scenario planning is best applied as a method for creating consensus on the overall vision or function of a corridor. This type of exercise typically emerges from tensions between transportation mobility and accessibility objectives in response to changing development patterns. In many urbanized areas, arterial corridors are increasingly being looked at for redevelopment and infill opportunities to support local economic development or growth management goals. With intensifying patterns of mixed use development comes a new emphasis on or a desire to increase transportation choices (mode split to transit, biking and walking).

Scenario planning in this context may involve the development of two or three big picture alternative visions for the corridor driven by differing redevelopment assumptions and includes a range of transportation targets for mode split, travel time by mode, pedestrian access to destinations, person throughput in corridor, auto travel time to the central business district, etc. For each scenario, TSMO professionals will be critical to identifying appropriate corridor-based TSMO strategies to achieve the desired targets. This process could also reveal new data collection and data collection technology needs that can be incorporated into subsequent TSMO planning efforts.

Opportunities to Consider Implications of Emerging Trends

Scenario planning is an excellent tool for considering TSMO issues and opportunities associated with "game-changing" demographic, economic, environmental, and technological trends. The section below highlights TSMO-related issues associated with emerging vehicle technologies and with generational demographic shifts which could be incorporated into scenario planning initiatives.

Connected/Autonomous Vehicle Technologies

The American Association of State Highway and Transportation Officials (AASHTO) Connected Vehicle Field Infrastructure Footprint Analysis asserts most motorists on American roadways by 2040 will be traveling in connected or automated vehicles (C/AV).³⁴ The preponderance of these technologies have a variety of potential outcomes that could be considered in long-range scenario planning exercises. Highway crashes will be dramatically reduced when vehicles can sense and adjust to surrounding events and hazards. In addition to the social and economic benefits of improved safety, reduced crash rates will also help to lessen incident-related congestion and thus improve travel-time reliability. Environmental impacts of vehicles and travel can be reduced when travelers can make informed decisions about modes and routes and when vehicles can communicate with the infrastructure to enhance fuel efficiency by avoiding unnecessary stops. Drivers can be provided with information about the proper speed to optimize their green light times on arterial corridors, and vehicles can be diverted to alternative routes in response to real-time congestion. C/AV vehicles can also be lighter than standard vehicles without compromising safety; the correspondingly improved fuel efficiency would have implications for both energy and environmental analyses.

Planning-related C/AV scenarios could also address land use, development strategies, and economic activity. With increased automation, car sharing may evolve into a service-on-demand industry that would shift car ownership from individuals to fleets. This would allow greater urban densities since parking requirements could be relaxed. Automated vehicles could replace existing inefficient transit feeder services and some line-haul services as well. On the other hand, these developments may result in reduced land use density, since commuting time can be used more productively.

In addition to planning for the long-term benefits of fully deployed C/AV technologies, TSMO planners can incorporate shorter term impacts of gradual system deployment. Initially there may be C/AV-only highways or lanes, with some level of automation or platooning provided.

In the medium term C/AV could support integrated corridor management (ICM) strategies by automatically balancing traffic between freeways and arterials. Small groups of drivers could be diverted with targeted messages, for example, which would be more effective than general dynamic message signs. It is important to note that the C/AV market may evolve gradually over decades, resulting in a mix of traditional and C/AV vehicles on roadways for years to come. Many other roadway users will not be in motor vehicles at all, such as pedestrians and bicyclists. Scenario planning processes provide opportunities to construct an understanding of these issues and implications and to develop new performance measures to track the emerging implications of new technologies.

Demographic Trends

Shifting cultural norms and generational needs and preferences have the potential to significantly affect travel demand in decades to come. America's up-and-coming workforce, dubbed the "Millennial" generation, is demonstrating significantly less interest in car ownership and a stronger preference for housing and employment in walkable, mixed-use towns and cities than their generational predecessors. It is not yet clear whether these preferences will "stick" as this generation moves into its child-raising years, but market studies indicate there is reason to believe that this generation will play an important part in generating demand for urban development and increased transportation choices that include more transit, walking, and biking options to meet their daily transportation needs.

Similarly, the aging "Baby Boomer" generation whose "nests" are emptying of young adult children is also demonstrating an increasing interest in walkable communities and urban lifestyles as they downsize their homes and anticipate the possibility of eventually choosing (or being forced) to give up driving. Scenario planning forecasts for medium- and long-term TSMO planning initiatives for corridors, regions, and States can be adjusted to consider related potential increases in urban density, mixed-use activity centers, and multimodal travel markets.

Environmental Trends – Weather Patterns

Scenario planning can also be an effective tool to help set specific performance targets for the transportation system under extreme weather conditions, which have been occurring with more severity and frequency over the past several years. After a significant event, like a major snow or ice storm in a southern city that shuts down the major highway system, policy makers and the public often express frustration over extreme commute times, stranded vehicles, and associated economic losses. Yet quite often the community or the region may have never asked themselves the question, "What is reasonable given certain extreme conditions?" While it may be difficult to anticipate or plan for a wide range of extreme events, a scenario planning process might be effective in helping to set expectations (as defined by performance measures) and reprioritize capital investments and management and operations plans.

To do this, a State or a region could develop a set of scenarios differentiated by different performance objectives in response to a major weather event. This would involve engaging a wide stakeholder group including first responders, major employers, schools, emergency workers, elected officials, and others to first begin a dialogue to establish priorities relative to making the transportation system operational after a major event. This group can then help to drive the scenario development. In the case of an extreme snow event, for example, performance targets could include making all roads accessible within 4 hours of the incident, making primary roads accessible to emergency crews only within 4 hours, or ensuring that all roads are cleared within 12 hours of the event. The scenarios could also look at economic impacts and focus in more strategic locations where interstate commerce or access to and from the regional central business district (CBD) may be a priority. Each scenario would be developed to include the full range of investments, new communication protocols, and other strategies needed to achieve the desired performance targets.

These scenarios could then be evaluated with the stakeholder group to discuss the tradeoffs—and most likely the benefit-cost analysis associated with the different levels of performance. This dialogue would likely result in a consensus on a set of performance objectives that can be achieved in response to an extreme event given specific funding levels or investments. This process could also likely lead to enhanced coordination and communication with the general public about how to better prepare and what to expect should a future event of extreme nature happen in their community.