NCHRP 08-36/Task 137: Assessing the Utility and Costs of Statewide Travel Demand Models Prepared by: Gregory D. Erhardt University of Kentucky Flavia Tsang RAND Corporation Danny Francis Requested by: American Association of State Highway and Transportation Officials (AASHTO) Standing Committee on Planning June 19, 2018

Make a budget request for statewide model development and maintenance Project Objectives Provide technical and planning staff at state transportation agencies with sufficient information to: Make a budget request for statewide model development and maintenance Articulate the value they expect to receive from statewide modeling Quantify that expected value The objectives of this project are listed here. Introduction

Method: Scenario Based Survey 2-hour structured web interview Respondents from 27 DOTs + 5 consultants The primary approach used to conduct this research was a series of structured interviews conducted via web conference. Each interview lasted about two hours. Respondents were individuals with knowledge of statewide modeling and/or statewide planning at 27 state DOTs, plus representatives of five consulting firms with expertise developing and applying statewide travel models. Introduction

Method: Scenario Based Survey The interviews were composed of three parts: Part 1: About You and Your Agency: Respondents were asked a series of questions about the agency that they represent. Part 2: Scenarios: Estimating Costs: In this section, respondents were asked to imagine that they have the ability to influence the selection of technical resources for planning. They were given a series of three model upgrade scenarios and asked to develop a budget estimate for doing so. Part 3: Scenarios: Go/No-Go Decisions: Again, respondents were asked to imagine that they have influence over the selection of modeling and technical resources. They were given a series of scenarios in which they must recommend a go/no-go decision for whether this new DOT should proceed with a statewide modeling project at the cost specified. This section included a total of nine scenarios, which vary based on the policies to be analyzed and on the type of model considered. The interviews were segmented into three parts as described here. After introducing the scenarios, the remainder of this presentation will be structured around these three main questions: 1) How do you classify existing statewide modeling practice, 2) what are the costs of statewide models, and 3) what is the utility of statewide models. Introduction

Scenarios: Segmented by model development option and policy focus The survey follows a set of nine scenarios segmented by model development option and policy focus. The model development options are described in the columns of this table, and build incrementally upon each other. Scenario M1 is to consider upgrading from no model to a basic 3-step model. Scenario M2 is to consider upgrading from a basic 3-step model to an enhanced 4-step model. Scenario M3 is to consider upgrading from an enhanced 4-step model to an activity based model. In each case the scenario assumes that the agency already has the previous model in place. In addition, the policy focus of each DOT is classified into one of three cases as described in the rows of this table. Each policy focus, going down the rows, also includes an interest in all of the policies described above it. While we recognize that there is a diversity of modeling approaches and policy interests among the states, this structure allows us to identify which states are most similar to each other. Introduction

Part 1: Classifying Existing Practice

Classification of Existing SW Model Practice This table shows how each state is classified into the modeling approaches and policy focus areas based on their existing practice. States we interviewed are classified based on their interview responses. States we did not interview are classified based on their responses to a previous survey. The states are also classified by population. Part 1: Classification

Part 2: Costs of Statewide Models

Reported 10-year spending vs population A previous survey asked states the total amount they spent on statewide modeling and associated data collection in the previous 10 years. The chart here shows those reported values plotted against the population of the state. Larger states are likely to spend more. Part 2: Costs

Example Cost Scenario Setup To estimate the cost of what it would take to develop a statewide model, we presented each of the model upgrade scenarios to the respondents giving a scope for a proposed project. An example is shown here. Part 2: Costs

Cost Scenario Worksheet Based on that description, we asked them to estimate the cost of building that model, broken into the categories shown here. Part 2: Costs

Estimated Model Development and Data Collection Costs This table summarizes the result of that exercise. The costs vary based on the size of the state and the type of model upgrade. Data collection, including household travel surveys are a large portion of the cost. Within each category there is significant spread in the estimates obtained, as indicated by the lower quartile and upper quartile estimates shown in parentheses. Part 2: Costs

Part 3: Value of Statewide Models

Policy Interest and Statewide Model Use The value of a statewide model is to evaluate proposed policies and projects. We asked respondents from each state to indicate whether the policies listed here are of interest to their agency, and if so, whether they are a priority to their agency. If the policy is of interest, we also asked whether they use a statewide model to conduct analysis for that policy. The results shown here indicate that some policies are of greater interest than others, and that statewide models are more commonly used to evaluate some policies than others. Often, the more diverse the range of policy interests an agency has, the more they report value in using a statewide model, and the more likely they are to see value in using a more sophisticated statewide model. Part 3: Value

Example Go/No-Go Scenario Setup To quantify the value respondents see in statewide models, we asked respondents for their recommendations on whether it would make sense to proceed with the statewide model development or upgrade projects described, at a given price point. Within each of the scenarios, we varied the cost from the starting estimate to understand the limits of their recommendation. The cost estimates were expressed in terms of “ten-year cost per capita”. This was defined as the total amount spent over a 10 year period, divided by the population of the state. The total cost includes the cost of the developing the model, the associated cost of data collection, and the cost to pay staff to operate and maintain the model. The slide shows an example setup for one of these go/no-go scenarios. Part 3: Value

Willingness to Pay for Model Upgrades, in 10-Year Cost per Capita The results of the go/no-go scenarios are summarized in this table. For a rural highways policy focus, respondents are willing to pay an average of $0.61 per capita over ten years to develop go from no statewide model to a Basic 3-Step Model. This would be $610,000 for a state with a population of 1,000,000, and $6,100,000 for a state with a population of 1,000,000. Moving down the rows, as the range of policies considered expands, the willingness to pay tends to increase. This is logical, because each policy focus is inclusive of all the policies above it. Going across the columns, the willingness-to-pay values are additive. For example, for the scenario of upgrading from a Basic 3-Step Model to an Enhanced 4-Step Model, respondents were instructed that the agency already has a Basic 3-Step Model, and the cost of developing that model is a sunk cost. The implication of that is that if someone is willing to pay $0.61 per capita to go from no model to a Basic 3-Step Model, and $0.54 per capita to go from a Basic 3-Step Model to an Enhanced 4-Step Model, they should also be willing to pay $1.15 per capita to go directly from no model to an Enhanced 4-Step Model. Part 3: Value

The Qualitative Case for Statewide Modeling Multiple states listed each the following as areas where statewide models are particularly valuable: Forecasting Traffic for New Facilities Bridge Analysis Detour Analysis and Emergency Route Analysis External Flows for Urban Models Economic Analysis Project Prioritization Respondents also identified areas where they saw particular value in statewide modeling. Common themes are summarized on this slide. For example, several respondents noted that without a statewide model it is still possible to forecast traffic on existing facility by extrapolating traffic count trends, but that a model is required to forecast traffic on new facilities. Part 3: Value

For questions, please contact: Greg Erhardt greg.erhardt@uky.edu Thank you to the program manager, Larry Goldstein, and to the NCHRP Project Panel for valuable input and guidance. For questions, please contact: Greg Erhardt greg.erhardt@uky.edu