In a PBPP process, the performance measures and targets that are established, together with policy considerations and principles agreed upon by policy makers, should be used as a basis for prioritizing and selecting transportation investments and policies. This step relies on data and analysis tools to help support informed analysis of strategies and predict performance outcomes. This section examines how to identify potential packages of strategies to achieve performance-based objectives, as well as the data and tools used to determine which strategies may be most effective.
Strategy identification, strategy analysis, and strategy selection determine how the PBPP targets will be achieved. Primary challenges often have to do with conducting analyses of a wide range of different types of investments (capital investments in highways, transit, non-motorized modes; management and operations strategies; infrastructure preservation) across a range of performance measures. In addition, tools are limited to assess the long-range impacts of investments on some types of metrics, although they are evolving.
Some common themes from professional practice include:
A primary benefit of a PBPP approach is that rather than starting out by looking at project needs, the focus begins by thinking about desired outcomes. This opens up consideration of a wide range of possible strategies that might not have otherwise been considered. Options include investments in a variety of highway, transit and non-motorized infrastructure, improvements to system management and operations, and transportation demand management, as well as opportunities to partner with local governments and the private sector to address land use and economic development efforts. It is important to take into consideration the balance and interrelationship of strategies and packages of investments to ensure that strategies have an overall positive effect.
The goals, objectives, measures and targets developed in the PBPP process guide the identification of strategies by providing specificity without dictating the approach. A successful process involves analyzing goals and objectives to identify possible strategies, particularly strategies that can accomplish multiple goals and objectives. For example, incident management strategies may be effective at reducing secondary crashes (supporting a safety objective) while also reducing nonrecurring delay (supporting an objective to reduce congestion). Similarly, "complete streets" strategies that involve utilizing sidewalks and bicycle lanes may help support multimodal accessibility and environmental quality or sustainability, while also improving system operations and efficiency.
New Jersey Long Range Transportation Plan - Diverse Strategies
New Jersey's Long Range Transportation Plan, called Transportation Choices 2030 (October 2008) was developed jointly by the New Jersey Department of Transportation (NJDOT) and NJ Transit. This policy plan provides broad direction for the transportation system, identifying key goals and performance measures, and a wide range of largely non-capacity enhancing strategies. The plan includes a heavy emphasis on integrating transportation-land use planning (smart growth) to support transit, walking, and biking. It also emphasizes the importance of ITS to improve operations; facilities to move more freight by rail and policies that support moving freight during nonrush hours; travel demand management measures to shift travel out of cars and shift travel times; and strategic improvements to address bottlenecks in the highway system. Transportation Choices 2030 supports maintenance and preservation of the existing system as a priority, and continued implementation of NJDOT's ITS Master Plan, which calls for significantly expanding the number of closed-circuit television cameras, electronic message signs on the state's highways, and continually improving the NJ511 free phone and Web service for transportation information.
More information is available at http://www.state.nj.us/transportation/works/njchoices/.
The field of safety provides an excellent case study of how focusing on an objective to reduce fatalities, supported by a data driven approach, can help to support consideration of a wide range of strategies, well beyond traditional transportation engineering solutions. The performance-based approach incorporated into the development of a Strategic Highway Safety Plan has demonstrated the effectiveness of this approach. Transportation safety is multidisciplinary, comprised of a broad range of strategies, often referred to as the 4E's: Engineering, Enforcement, Education, and Emergency Response. For transportation planners and engineers, safety is a factor in how projects are designed and prioritized. Input from user groups, such as the elderly and teen drivers can help direct design. Law enforcement officials work to ensure traffic safety is a major part of their activities, while safe driving educators work to reduce fatalities through altering travel behavior such as intoxicated or distracted driving. Lastly, emergency response teams work with transportation planners to improve response time to incidents.
An SHSP involves collection of data on the location of crashes, types of crashes, and underlying causes of traffic fatalities in order to prioritize strategies. Knowing whether the majority of fatalities are caused by drivers' behaviors, intersection design, long emergency response times, or other factors can allow stakeholders to identify key strategies that will effectively work towards meeting the performance-based targets. It can also help to target limited funding to the most effective improvements.
Ohio DOT's Strategic Highway Safety Plan
ODOT's SHSP notes that the SHSP "asks government agencies and safety advocates to work across jurisdictional boundaries to address crash problems regardless of where they occur." It includes a wide range of strategies, and ODOT has developed a multidisciplinary safety review committee that includes representatives from roadway design, traffic operations, and safety planning and data analysis. This committee is directly involved in project selection for projects that are funded through the Safety Program. The Systematic Signal Timing & Phasing Program (SSTPP), which was launched in 2008 and is designed to evaluate and update the timing and phasing of signal systems in congested, high-crash corridors where signal timing can be linked to crashes. The program was developed based on a number of national studies that demonstrated a link between improved signal timing and significant reductions in crashes, travel times, fuel costs, and air quality improvements.
Similarly, there are a wide range of strategies available to address accessibility, reliability, mobility, and congestion management goals. These may include transportation capacity projects (i.e. bottleneck relief projects, additional highway lanes, transit service); demand management strategies (i.e. parking management, high-occupancy vehicle lanes, and pricing), and operational strategies (i.e. traffic signal retiming, incident management, and traveler information), as well as land use strategies and other considerations. A transportation asset management approach also supports consideration of a range of investment strategies to manage physical assets over their life to support long-term sustainability.
This part of the PBPP process should begin with exploring all potential strategies. Once goals, objectives, measures and targets have been discussed, vetted, and established, agencies engaged in PBPP will have a stronger sense of the relative importance placed by the public, stakeholders, and agency officials on performance on various areas such as safety, mobility, accessibility, reliability, and asset condition. With this information, agencies begin to formulate strategies that attempt to balance these priority areas through packages of investments that reflect this balance. Based on understanding of financial constraints and risks, technical staff, working with policy decision-makers, often develop packages, or combinations, of strategy approaches for further consideration. Development of these packages should build upon data and tools including bridge management, pavement management, congestion management, and other systems. These packages can include a range of activities including capital investments in highways, transit, and non-motorized modes, operational improvements, and other possible strategies, like land use or pricing policies and may require input from many perspectives, including transportation planners, community leaders, public, environmental specialists, landscape architects, resource agencies, public works officials, and design engineers.
PSRC: Consideration and Analysis of a Broad Range of Strategies
The Puget Sound Regional Council (PSRC), the MPO for the Seattle region, explored a wide range of strategies to meet performance objectives in its Transportation 2040 Plan, including a range of capital, operations, and pricing strategies. PSRC utilized performance measures and benefit-cost analysis in considering alternatives. Recognizing the value of road pricing to support several performance outcomes, including travel time savings, reliability benefits, and reduction in vehicle emissions, and the role if could play in funding investment needs, the Plan includes congestion pricing as a key element of its Transportation 2040 Plan with a financing plan that suggests a long-term shift in how transportation improvements are funded. The plan calls for full highway system tolls by approximately 2030.
For more information, see: http://www.psrc.org/transportation/t2040/
Data and analysis tools play an important role in prioritizing strategies as part of a PBPP process. Three primary types of analysis often are used:
1. Historical data: Collecting data to understand past and existing system performance. This data can be very important for analyzing the causes of problems and in pinpointing the location of problems in order to help prioritize the types of investments and strategies that are needed. For instance, data are typically used to assess and understand the causes and location of crashes. Collected operations data is often used to understand and pinpoint congested locations as part of a CMP, and mapping congestion bottlenecks can help in assessing needs for improvements.
As an example of using data to assess system performance and to prioritize strategies, the Baltimore Metropolitan Council's Regional Transportation Board is using Inrix (a private company) data and a regional integrated traffic information system, which is an automated data sharing, dissemination and archiving system developed by the University of Maryland Center for Advanced Transportation Technology (CATT) Lab. The Baltimore Regional Transportation Board (BRTB)'s Vehicle Probe Project ranks bottlenecks ranking through data collection based on individual vehicles, and is providing enhanced information to improve performance.
Washington State's SHSP Target Zero: Using Data to Prioritize Efforts
Washington State set an aggressive goal for itself: "zero traffic deaths and serious injuries on Washington State roads by 2030." While this is an aspirational goal, the coordination of stakeholders, including local governments, Tribes, state and federal agencies, the private sector, and non-profit and community groups working together has resulted in significant progress. Target Zero provides a comprehensive framework of goals, objectives, and strategies for reducing traffic fatalities and serious injuries, which is incorporated into the plans and programs of key traffic safety agencies. It involved significant analysis of trends in fatalities, types of crashes, and contributing factors, in order to develop priority rankings based on the percentage of traffic fatalities associated with each factor.
2. Forecasting tools: Forward-looking analyses are conducted to assess anticipated performance of the transportation system under different future investment scenarios. The most commonly used tool for forecasting is a regional travel demand model, which can be used as a basis for forecasting vehicle travel, emissions, access to transit, and other metrics.
NCTCOG: Modeling of Traffic Congestion Levels
The North Central Texas Council of Governments (NCTCOG), the MPO for the Dallas-Ft. Worth area, used its travel model to forecast congestion levels in the future. This analysis used in the CMP, was also used as a basis for analyzing alternative investment strategies in the development of its Metropolitan Transportation Plan.
In addition, crash predictive tools and techniques allow consideration of safety impacts in planning. For instance, the HSM provides the ability to assess anticipated changes in crash frequency or severity, so for instance, if an agency is considering an access management policy on all arterial roadways throughout the community, the HSM provides crash modification factors that quantify the change in crash frequency or severity associated with changing driveway density. Therefore, the planners can estimate changes in safety performance, along with traffic operations.
3. Economic analysis tools and management systems - Economic models and management systems can be used to support tradeoff analysis. Examples of such tools include the Highway Economic Requirements System (HERS), bridge management systems, and pavement management systems. As an example, the Southeastern Michigan Council of Governments (SEMCOG) utilized the Highway Economic Requirements System (HERS), asset management systems, and other sources to develop relationships between investment levels and performance measures for a range of program areas (pavement preservation, highway capacity, bridge preservation, safety, transit, non-motorized, and roadway operations). SEMCOG selected a single measure in each program area for analysis, and conducted an analysis of the relationship between future performance and expenditure levels. The results were combined into AssetManager NT, a visualization tool that enables users to conduct "what if" analysis for testing different investment options. A more detailed description of SEMCOG's process is presented in the Case Studies section (Chapter 11) of this Guidebook.
Tied into the analysis techniques discussed above, packages of strategies can be analyzed using scenario planning, an analytical approach that provides a comprehensive framework for evaluating how various combinations of strategies, or scenarios, may affect system performance at the statewide or metropolitan level. The approach involves identifying various packages or strategies or scenarios against a baseline projection. Scenario planning is often an inclusive and interactive process - using hands-on activities, renderings and schematics to visually depict various scenarios - which can improve citizen participation and political buy-in, and result in more informed decision making.
Within the context of performance-based transportation planning, the scenario planning approach helps visualize and articulate, in both qualitative and quantitative terms, how the combination of various strategies would help meet performance targets. It allows for the consideration of how various factors, such as revenue constraints, demographic trends, economic shifts or technological innovation can affect a state or region and its transportation system performance.
While scenario analysis may apply to State DOTs, MPOs, RTPOs, transit agencies, and other entities, federal law notes that, "A metropolitan planning organization may, while fitting the needs and complexity of its community, voluntarily elect to develop multiple scenarios for consideration as part of the development of the metropolitan transportation plan." MPOs that choose to develop multiple scenarios are encouraged to consider [23 USC Section 134(i)(4)]:
DRCOG: Scenario Planning to Assess Alternative Transportation and Land Use Policies
In Denver, Colorado scenario planning is used in regional planning efforts to consider the impact of both transportation and land use policies. As part of its 2035 Metro Vision plan update process, the Denver Regional Council of Governments (DRCOG) engaged in scenario modeling to determine how a variety of transportation and development policies would affect environmental, economic, and efficiency outcomes for the region. The model looked at six different scenarios, each of which had a unique combination of transportation and land use policies. Potential transportation policies included varying levels of highway and transit investments; land use policy options ranged from an emphasis on compact development to expansive development. The modeling exercise found that the scenario with compact development and an emphasis on transit resulted in less congestion, fewer VMT, greater access for low-income residents to employment by transit, and lower public infrastructure costs. The findings from this modeling exercise influenced the Council's decision to expand the region's urban growth boundary by less than a third of the amount it had initially considered, which will have impacts on the efficiency of transportation, as well as livability, in the region.
SANDAG: Scenario Planning Addressing Funding Levels
The San Diego Association of Governments (SANDAG) conducted scenario planning to evaluate how different levels of funding and packages of investments and growth strategies would affect performance in terms of accessibility of destinations to users of different transportation modes. Figure 5 below highlights findings in relation to accessibility measures. Comparisons such as this allow policymakers and the public to see the correlation between funding and performance and can facilitate clearer discussions of priorities based on constraints.
Figure 5: San Diego Association of Governments - Accessibility Measures
Scenario planning often incorporates visualization methods to depict scenarios to facilitate public engagement and improved decision-making. As an example, the Southeastern Michigan Council of Governments (SEMCOG) implemented a unique system that allows for visualization of system-level tradeoffs between possible resource distribution scenarios. SEMCOG held public meetings where maintenance costs and funding procedures were explained to the attendees to help them better understand the scenario planning process. SEMCOG also provided "investment versus performance" graphics that illustrate how current prioritization differs from the public's preference for goal prioritization, helping to facilitate discussions about future investments.
VTrans Asset Management Scenarios Showing Link between Funding and Performance
The Vermont Agency of Transportation (VTrans) has used scenario analysis to demonstrate a clear link between funding levels and anticipated performance on asset management. The chart below, from the Agency's Asset Management Vision and Work Plan, compares expected results under various scenarios ranging from doing nothing (no investment) to investing $80 million per year in pavement maintenance.
Source: VTrans Asset Management and Work Plan, http://vtransplanning.vermont.gov/sites/aot_policy/files/documents/planning/VTrans_Asset_Mgmnt_VW.pdf
NJTPA Scenario Planning
The North Jersey Transportation Planning Authority (NJTPA) engages in scenario planning to explore and understand potential and appropriate responses to changes in demographics, travel patterns, and transportation needs in the region. For its Plan 2035, NJTPA identified and evaluated three different scenarios - a baseline scenario, one based on Plan 2035, and an aspirational scenario. Each was evaluated using demographic and travel data, input from visioning workshops that were conducted as part of the plan update process, and a regional travel demand model that gauges the effect of land use and transportation choice changes.
Source: NJTPA LRTP Scenario Planning, http://www.njtpa.org/getattachment/Planning/Plan-Update-to-2040/Plan-2035/RTP_2035_Chap5-(1).pdf.aspx.