Office of Operations
21st Century Operations Using 21st Century Technologies
Table of Contents

Operations Benefit/Cost Analysis TOPS-BC User's Manual – Providing Guidance to Practitioners in the Analysis of Benefits and Costs of Management and Operations Projects

Chapter 3. Investigate the Range of Impacts Associated with Various Operations Strategies

Overview

The first key capability provided in TOPS-BC is the ability to investigate the range of impacts associated with various operations strategies. Practitioners often have the need to research and identify the potential high level impacts of various operations strategies. For example, you may need to identify the typical range of speed change related to a ramp metering deployment. This information may be needed to fulfill a request to provide basic justification of the potential benefits of strategies to communicate to decision makers or the public, or may be needed to provide input parameters on the potential impacts for use in a B/C analysis. The TOPS-BC application is intended to provide guidance regarding the potential benefits of a wide range of TSM&O strategies in order to fulfill these needs.

TOPS-BC maintains an internal database of impacts and benefits observed for specific strategies when deployed in various regions in the United States and abroad. This information has been compiled from the ITS Joint Program Office’s Benefit Cost Database and numerous other sources. Additionally, input parameters used in several operational analysis tools are also documented in the database for additional guidance.

The number of data points associated with any particular strategy and individual impact is often related to the maturity of the strategy and the number of real-world evaluations that have been conducted to date. Well established strategies may have many benefits data points available from multiple locations. New and emerging strategies may have only a limited number or no empirical data points available. Cells in the database have been reserved, however, to be populated at a later date as benefit information becomes available on these strategies. Similarly, not all strategies are anticipated to impact all types of benefits. Therefore, many impact categories for a particular strategy may not contain information.

Using Capability 1 to Investigate the Range of Impacts Associated with Various Operations Strategies

To navigate to the worksheet providing this capability, click on the appropriate box on the opening screen, or simply select the blue worksheet tab named “Impact Lookup.” The Impact Lookup sheet is shown in Figure 3-1.

Figure 3-1. Impact Lookup Worksheet

Figure 3-1 is a screen shot of the Impact Lookup sheet.

Source: Federal Highway Administration.

On this worksheet, select a particular strategy and impact category you are interested in researching. When selecting particular strategies, you may be asked to define the sophistication of the strategy. For example, Ramp Metering has separated menu items in the pull down menu for pre-set, actuated and central control timing. Upon selecting these inputs, a range of observed impacts may be displayed under the “Noted Impacts.” This range is based upon a review of available data by the tool developers.

If insufficient data was available to identify an appropriate range of potential impacts, a message stating “Not enough data available” will appear. Figure 3-2, also presented in the Desk Reference, provides a mapping of the generally recognized benefits associated with various operations strategies. While not an absolute mapping of empirical data maintained in the database, the table provides a hint to where the most data is likely available.

Figure 3-2. TSM&O Strategies Mapped to Likely Impacts on MOEs

Figure 3-2 is a table showing seven Transportation Systems Management and Operations (TSM&O) Strategies and seven Measures of Effectiveness (MOE) and whether the MOE is primarily associated, secondarily associated, or not associated with the strategy.

Source: Federal Highway Administration.

Ranges of data shown on the Impact Lookup worksheet are individual high-level summaries of the observed impacts from empirical studies and other data from existing B/C analysis tools. The message displayed under the “Noted Impacts” heading is hyperlinked directly to a summary of studies and existing tool input parameters used in developing the estimated range. Figure 3-3 shows a sample data point representing a view of the Speed/Travel Time impacts related to ramp metering deployments.

Figure 3-3. Sample Display of High-Level Empirical Data Maintained in TOPS-BC

Figure 3-3 is a screen shot of a sample data point display.

Source: Federal Highway Administration.

The default data displayed in the database shows only very high-level summaries of the data. Data related to particular strategies is presented in rows, while columns display data related to specific impacts. The database is not intended to be a comprehensive presentation of data, but instead is intended to provide a “quick look” overview of the available data and observed impacts (generally expressed as a simple percentage change whenever possible).

The database does not document the specifics of the deployment or evaluation effort that produced the data point. Instead, a hidden column located to the right of each impact category column contains a reference for the data’s source documentation, providing you the opportunity to further investigate the specifics of particular data points.

To view the reference data for each individual data point, follow the normal Excel process for viewing a hidden column. Highlight the entire column for the impact of interest and the column located immediately to the right of that column. Once selected, perform a right-mouse click, while the mouse is positioned over the alphabetical column headings, and select “Unhide” from the pop-up content menu.