Formulation and Performance Analysis of Solution Alternatives
In this step of the DM process, agency staff further develop the potential initiatives identified so that both decision makers and the wide spectrum of stakeholders have a thorough appreciation of their potential impacts. For example, an initiative to reduce truck double-parking in a busy downtown area is the implementation of a delivery appointment system, to ensure that delivery trucks are able to find off-street parking. As part of the formulation phase, important questions must be answered: What size buildings would be the focus of the initiative? Would the system be required, or encouraged? Would incentives be provided? If so, in what amounts? What geographic area would be the focus? What impacts would be produced by the initiative? The answers to these questions provide a fuller view of the benefits, costs, and level of effort associated with the initiative(s). Such information, both qualitative and quantitative, provides a solid foundation for DM.
In estimating the performance of the various initiatives it is important to be thorough but pragmatic. Essentially, the data collection and performance analysis need to be commensurate with the scope and potential impact of each initiative. The FHWA Desk Reference provides a detailed discussion of the process, tools, and techniques that can be used to analyze the performance of traffic management strategies (Federal Highway Administration 2012c). The behavioral micro-simulation model (Silas and Holguín-Veras, 2009) and the freight demand estimation model (Holguín-Veras and Aros-Vera, 2014) are specifically helpful for analyzing alternatives involving freight demand management. However, large data collection and modeling exercises are best reserved for only the largest and most impactful projects.
Tasks involved in formulation and performance analysis of solution alternatives are:
- Data collection
- Data are collected that relate to each possible alternative. The data collected include cost, time and effort required for implementation, complexity, and potential risks and benefits.
- Agency staff lead a process to provide a clear picture of what each initiative would entail. Doing this allows an understanding of the full spectrum of impacts, including what will be required from the transportation agencies and all stakeholders for a successful implementation.
- Assessment and analysis
- Agency staff assess the key impacts of the various alternatives. Traffic simulation models could be used to assess the local impacts of proposed initiatives (e.g., to assess how a new land use policy would impact freight traffic volumes, a regional planning model could be used to get a general idea about regional congestion impacts). These modeling endeavors are designed to ensure a reasonably solid understanding of the behavioral changes that a proposed public-sector initiative could induce. Possible methods include in-depth-interviews with selected industry representatives, focus groups, or stated preference surveys. Guessing how the freight industry would react to any given initiative is a significant challenge, so outreach to those industry sectors that would be impacted is highly advisable. Projected unintended impacts of the alternatives (e.g., traffic increases in sensitive areas due to adding an extra lane, or population shifts from building a bypass) need to be identified and evaluated.
- Additional assessments of budget, staffing, and timing for the selected alternatives may be needed. For example, before recommending an OHD program, it is advisable to check with the private sector to determine the feasibility of the idea.
- Generation of outputs
- Outputs from this task are:
- Clear and solid descriptions of the initiatives being considered, together with technical assessments of their potential impacts.
- Preliminary conclusions concerning the merit of each initiative.
- Outputs from this task are: