15.3.2 Typical Measures of Effectiveness (MOE)
The monetized benefits in a B/C analysis are calculated by applying an established unit value for each MOE and then applying that value to an estimated change in the identified MOEs for the project being analyzed. The MOEs described below are factors often influenced by TSMO and TDM projects and commonly used as a basis for assessing a particular project’s positive or negative impacts.
15.3.2.1 User Travel Time Savings
User travel time is the most used MOE for more traditional capacity-related transportation improvements as well as TSMO projects. User travel time savings refers to the change in the sum of all person hours of travel (PHT) resulting from the implementation of a TSMO project. However, this MOE is a measure of the average, recurring travel time. Many TSMO projects target reducing travel times impacted by nonrecurring factors, such as incidents or construction activity. Because of this, using only this measurement may result in underestimating the benefits of a TSMO project.
Travel time can include time spent inside and/or outside of a vehicle, depending on the mode choice the analysis considers, such as a transit or active transportation alternative. Different monetary values of travel time can also be assigned, depending upon the nature of travel in question. For example, on-the-clock freight vehicle travel time can be assigned a higher monetary value than passenger car leisure travel time.
15.3.2.2 User Vehicle Operating Costs
User vehicle operating cost is also a commonly used MOE for assessing both traditional capacity-related transportation improvements and TSMO projects. User vehicle operating costs can be split up by fuel use or nonfuel use costs. Nonfuel costs include maintenance, insurance, and vehicle depreciation costs. The fuel use MOE is typically estimated by applying a rate of average fuel use to the net change in vehicle miles of travel (VMT).
15.3.2.3 Crashes
Many TSMO projects have been shown to significantly reduce the number of crashes, as well as the severity of vehicular crashes when they do occur. TSMO projects may reduce the chance of crash exposure by smoothing the flow of traffic and alerting drivers of potential interferences. TSMO projects may also reduce the severity of crashes by improving the emergency response to incidents through shorter response times and improved preparedness. The costs associated with crashes include the actual costs, such as medical treatment and property damage, and the cost to avoid, which is an estimate of the value that individuals would be expected to pay to avoid being involved in a crash.
15.3.2.4 Emissions
A more complex MOE used for both traditional capacity-related transportation improvements and TSMO projects is emission levels. The emissions categories typically include hydrocarbons (HC)/reactive organic gases (ROG), nitrogen oxide (NOx), carbon monoxide (CO), carbon dioxide (CO2), particulate matter (PM10) or fine particulate matter (PM2.5), and sulfur dioxide (SO2). Most emissions estimates are based on the application of an emissions rate per VMT. However, emissions rates are sensitive to a variety of variables, such as vehicle speeds and type of vehicle.
15.3.2.5 Emerging MOEs
New MOEs have recently been introduced to B/C analysis to evaluate the effectiveness of emerging TSMO strategies: travel time reliability, incident-related delay, and consumer surplus. These emerging MOEs often provide more justification for TSMO projects, as these MOEs are the focus of many operations deployments.
- Travel time reliability is the variability in travel times caused by both nonrecurring and recurring congestion sources.
- Incident-related delay includes factors that relate to a facility’s capacity.
- Consumer surplus refers to the difference between the amount users are willing to pay in terms of travel costs, including time and money, and how much they pay. Consumer surplus is usually used in the assessment of travel time savings.