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Center Identification Number:  77932

Project Title: Estimating Costs and Benefits of Emissions Reduction Strategies for Transit by Extending the TRIMMS Model

Principal Investigator:

Sisinnio Concas

Center for Urban Transportation Research
University of South Florida

Phone: 813-974-7760
Fax: 813-974-5168


External Project Contact:     

Amy Datz, Project Manager
Florida Department of Transportation
Transit Project Manager
Phone: 850-414-4239

Start and End Dates

Start Date:  March 2011               Expected End Date: March 2012

I.  Project Objective/Problem Statement

Investment in public transportation can provide a cost effective and efficient means to reduce greenhouse gas emissions (GHG). The Florida Department of Transportation (FDOT) has been actively engaged in identifying GHG reduction strategies for transit. Additionally, FDOT is working on creating a GHG baseline for each transit agency in Florida and research efforts have focused on ozone emission reductions.

When prioritizing transit capital investment strategies geared at emission reductions, focusing on ozone emissions can result in a limited evaluation of some scenarios or strategies. For example, while investments in bus rapid transit might represent a cost efficient solution due to lower capital and infrastructure costs, it might prove less efficient compared to light rail transit in terms of emission reduction attainment when the whole range of pollutants is taken into consideration.

Evaluation tools that focus only on ozone reduction strategies may underestimate the relevance of other criteria pollutants. Transit services such as bus transit and bus rapid transit usually rely on diesel fuel, which produces other health treating pollutants, such as particulate matter (PMX). Fine inhalable particles tend to have the greatest impact on human health as they pass deep into the lungs thus leading to severe respiratory diseases.


II. Objectives/Tasks

The objective of this research is to extend the evaluation of transit emission reduction strategies to provide a methodology for assessing the full benefits and costs associated with the implementation of the ozone reduction strategies and to account for a broad spectrum of emission pollutants. The range of pollutants will include carbon dioxide (CO2), carbon monoxide (CO), volatile organic compounds (VOCs), nitrogen oxide (NOx), sulphur oxide (SOx), and particulate matter (PM).

This objective will be accomplished by extending the TRIMMS© model (Trip Reduction Impacts of Mobility Management Strategies) developed under previous NCTR projects funded by FDOT.

TRIMMS is a sketch planning spreadsheet based application designed to evaluate travel demand management initiatives, which also include emission reduction strategies of transit investments focused on access and travel time improvements. TRIMMS is currently being used by several local planning agencies across the U.S., by the Washington State Department of Transportation, and also by the Environmental Protection Agency.

TRIMMS enables the user to quantify the net social benefits of a wide range of transportation demand management (TDM) initiatives in terms of emission reductions, accident reductions, congestion reductions, excess fuel consumption, and adverse global climate change impacts. Under the “Quantifying the Net Social Benefits of Vehicle Trip Reductions: Guidance for Customizing the TRIMMS© Model” NCTR project, CUTR made numerous improvements to the TRIMMS model. For example, TRIMMS 2.0 now includes a sensitivity analysis module that provides program cost‐effectiveness assessment. This feature allows conducting “TDM evaluation to meet the Federal Highway Administration Congestion and Air Quality (CMAQ) Improvement Program requirements for program effectiveness assessment and benchmarking. The project’s final report provides guidance to help TDM professionals to use the model by selecting the appropriate cost parameters, providing referenced sources where such parameters can be obtained, and by offering general guidance on how to incorporate data already at their disposal.”

Under the “Incorporating Assumptions for TDM Impacts in a Regional Travel Demand Model” project for WSDOT, CUTR devised an approach to forecast the magnitude and geographic distribution of changes in travel patterns likely to result from more aggressive TDM programs. (Will this program only be useful for aggressive programs and not applied across the board for all TDM plans or programs or other types of plans? Will the application be very narrow?) Such an approach provides a capability to estimate the effect these changes will have on delay, speed, and travel time throughout affected corridors. This project developed a Transportation Demand Management Assessment Procedure (TDMAP), as a sketch planning modeling approach to incorporate TDM into WSDOT’s travel demand model. TDMAP does so by (1) extracting mode split tables from the model; (2) processing them to be compatible with TRIMMS 2.0, an existing tool that estimates changes in travel behavior as a result of implementing different TDM strategies; (3) running the tables through TRIMMS 2.0; and then (4) processing them back into the four-step model for distribution over the transportation network.

This study proposes to extend TRIMMS to develop a set of modules focused on transit investment evaluation, leading to an add-on to the model.

TRIMMS, as opposed to currently available calculators (such as the Conserve by Transit I calculators), will allow transit agencies and others to easily estimate the rate of return for investments in emission reduction strategies. Current emission assessment frameworks can provide a calculation of the emissions generated only from transit operations (i.e., how much the transit agency itself contributes to GHG emissions). However, this project would result in a model to enable FDOT, transit agencies, MPOs and local communities to quickly estimate changes in emissions and the societal benefits in changes in travel behavior in a similar manner as highway cost/benefit analyses. They will be able to calculate cost/benefit for most of the strategies identified in the FDOT-sponsored Transit Ozone-Reduction Strategies Toolbox without the cost and expertise required of more sophisticated models.

Work not included in this scope of service is not to be performed and will not be subject to compensation by the Department.

Task 1. Project Kickoff and Project Management

This task will cover project management at CUTR including producing required progress reports and carrying out deliverable reviews before submittal to FDOT. A kick-off meeting shall be scheduled to occur within the first 30 days of execution by the university. The preferred method for the kick-off meeting is via teleconference or video conference. As a minimum, the project manager and the principal investigator will attend. The Research Center staff shall be advised of the meeting and given the option to attend. Other parties may be invited, as appropriate. The subject of the meeting will be to review and discuss the project’s tasks, schedule, milestones, deliverables, reporting requirements, and deployment plan. A summary of the kick-off meeting shall be included in the first progress report.

Task 2. Identification of Quantifiable GHG Emission Reduction Strategies

FDOT, through the Conserve by Transit (CBT I) project, recently developed a set of emission calculators for Florida transit agencies. The purpose of CBT I was to develop a set of calculators to estimate changes in ridership levels that would result in the absence of transit services and vehicle-miles of travel changes by displacement. The calculators, though, do not estimate or predict any change in transit ridership levels or VMT resulting from improvements in transit services or from the implementation of any of the strategies identified in the FDOT’s Transit Ozone-Reduction Strategies Toolbox.

The objective of this task is to extend TRIMMS to evaluate a broader set of strategies that transit agencies can pursue. In particular, CUTR will rely on the strategies identified in FDOT’s Transit Ozone-Reduction Strategies Toolbox at This task will consider the estimation of the impacts as outlined in the Toolbox:

• Direct Transit Improvements

• Indirect Transit Improvements

• Employer-Based Commuter Programs

• Other strategies to expand transit service

• Strategies that promote compact land-use development

The identification will also consider strategies that transit agencies can pursue to reduce their own vehicle emissions, such as the use of alternative fuels and vehicle types, changes in facility construction and maintenance practices, and other strategies leading to increased use of renewable energy. The PI also will coordinate with CUTR PIs for the Toolkit for Carbon Footprint that Integrates Transit and the Conserve by Transit II projects to avoid effort duplication.

Task 3. Input Parameters Data Collection and Analysis

At the core of TRIMMS is the capability to estimate mode share and vehicle miles of travel (VMT) changes generated by TDM strategies directly affecting the monetary and time cost of travel and by employer-based TDM initiatives. The estimation of modal share changes are based on a constant elasticity of substitution (CES) demand functions.

The objective of this task is to extend the current version of TRIMMS to estimate GHG emission reductions from expanded transit vehicle service by considering the impact on private vehicle displacement generated by transit access and travel time improvements.

In the current version of TRIMMS, the default parameters already allow estimating impacts for seven major urban areas in Florida. In keeping with the overall mission of the National Center for Transit Research, the proposed extension will focus on Florida agencies and Florida impacts, while retaining a platform that allows TRIMMS to be used nationwide.

Under this task, the principal investigator will proceed to collect all necessary input parameters required to estimate the identified GHG reduction strategies, specifically:

• Revisit each mode demand function to incorporate additional elasticities that allow estimation of impacts from those strategies identified in Task 2.

• Update default parameters statistical areas loaded in the current version of the model, focusing on default parameters that are specific to Florida.

• Update the emission parameter database using the Environmental Protection Agency Motor Vehicle Emission Simulator (MOVES2010).

Task 4. TRIMMS Update to Version 3.0 with Expanded Transit Module

The objective of this task is to implement an updated version of the model to estimate the impact of transit strategies identified in the Ozone Toolkit. The principal investigator will proceed to design and implement the Excel Visual Basic modules necessary to estimate all impacts (identified in Task 2) to generate a transit-specific estimation module. As part of this effort, an online version of the model will also be developed.

The transit module will be linked to the underlying Monte Carlo sensitivity analysis module already embedded in TRIMMS. This module is intended to help practitioners estimate the probability that program benefit-to-cost ratios will at least equal or greater than some predetermined benchmarking value.

Note that although the data used in CBT I and TRIMMS are compatible, the methodology used to calculate changes in VMT and the resulting GHG emissions is different. CBT I calculators use mode shift factors to estimate changes in VMT in the absence of transit services. TRIMMS relies on elasticity factors to estimate changes in VMT and ridership levels resulting from the implementation of strategies that improve transit services, incentives to use alternative modes, and other transportation demand management (TDM) initiatives.

For example, compared to CBT I, the emission factors used in TRIMMS are more disaggregate and specific to the area under analysis. TRIMMS has default emission parameters that come directly from running the EPA Mobile 6 model, which take into account different in ambient temperatures and average speed.

Finally, while the CBT I is defined as a calculator, TRIMMS is a model. A calculator does not predict anything, rather, it just computes given a set of inputs. CBT I calculators take as given expected changes in ridership levels and then computes changes in GHG emissions. TRIMMS is a predictive model. It estimates changes in travel behavior. TRIMMS estimates changes in travel instead of taking them as given. The Monte Carlo simulation component of TRIMMS also considers a range of possible outcomes.

To the extent possible, the PI will implement refinements to the model structure to consider compatibility and consistency issues with the CBT I calculators.

It is expected the new version of the model will be subjected to internal and outside testing by a selected group of practitioners in concurrence with the assigned FDOT project manager. It is expected that, following the kick-off meeting under Task I, the evaluation panel will be composed of members from the Task Team of the Ozone Toolkit.

Task 5. Guidance to Model Use and Customization

The objective of this task is to produce a technical document to help professionals to use the model to estimate the benefits associated with the implementation of the Ozone Toolkit strategies and customize the cost parameters. The document will provide references to sources where such parameters can be obtained. It is anticipated that this document will appear as an appendix in the final report. The final report will be written in the Governor’s directed Plain English so that planners and elected officials in city and county governments will be able to understand the functionality of the program.

Task 6. Final Report

At the conclusion of the project funding period (90 days before the end date), CUTR will summarize and synthesize all of the data collected in the previous tasks and provide a draft final report to FDOT’s Research Center. The 90-day review period will allow adjustments resulting from FDOT comments.

The revised document will be provided to the FDOT Project Manager and the Research Center within 12 months of the issuance of the Task Order. Further details on the final report are described below in the section “Deliverables.”


III. Deliverables

Project Kickoff Meeting

A kick-off meeting shall be scheduled to occur within the first 30 days of execution by the university. The preferred method for the kick-off meeting is via teleconference or video conference. As a minimum, the project manager and the principal investigator will attend. The Research Center staff shall be advised of the meeting and given the option to attend. Other parties may be invited, as appropriate. The subject of the meeting will be to review and discuss the project’s tasks, schedule, milestones, deliverables, reporting requirements, and deployment plan. A summary of the kick-off meeting shall be included in the first progress report.

Progress Reports

The Principal Investigator will submit quarterly progress reports to the Research Center. The first report will cover the activity that occurred in the 90 days following the issuance of the Task Work Order.

Reports should be submitted within 30 days of the end of the reporting period. Reports are due even if little or no progress has occurred (in which case, the report should explain delays and/or lack of progress). Progress reports should be sent in MS Word to Sandra Bell, not to the Project Manager

Progress reports must include the following information: 1. Contract Number, Task Work Order Number, and Title in the report and in the subject line of all e-mail correspondence for the submission of reports. 2. Work performed during the period being reported 3. Work to be performed in the following period 4. Anticipated modifications (i.e., to funding, schedule, or scope). This section is for reporting/informational purposes, not for officially requesting an amendment. Note: To request an amendment to a contract, the contractor must provide the project manager with the appropriate information (i.e., what is being requested with justification) in the required format. If the project manager concurs with the request, he/she shall forward it with his/her approval and commentary, as appropriate, to the Research Center for administrative review and processing (pending available funds, etc.) 5. A Progress Schedule (figures A, B, and C) updated to reflect activities for the period being reported.

Failure to submit progress reports in a timely manner may result in termination of the work order.

Draft Final Reports

The Draft Final Report is due 90 days prior to the end date of the task work order. The draft final report will be submitted to Sandra Bell, It should be edited for technical accuracy, grammar, clarity, organization, and format prior to submission to the Department for technical approval. The Executive Summary in the beginning of the report must be written in the Governor’s prescribed Plain English. The Principal Investigator will provide a double sided copy of the report for the Project Manager’s review. The Research Center expects contractors to be able to provide well-written, high quality reports that address the objectives defined by the scope of service. Draft final reports must be prepared in accordance with the “Guidelines for Preparing Draft Final and Final Reports.”

Final Reports

Once the draft final report has been approved; the university shall prepare the final report. The university will deliver a minimum eight (8) copies on CD or DVD – seven (7) CDs should contain the final report in PDF format, one (1) CD should contain the final report in PDF format, MS Word format and a Summary of the Final Report. The CD/DVDs should be labeled in a professional manner and include at a minimum the contract number, task work order number, project title and date.

The final report is due no later than the end date of the task work order and should be delivered to the following address:

The Florida Department of Transportation Research Center, MS 30 605 Suwannee Street Tallahassee, FL 32399-0450

Project Closeout

A closeout meeting shall be scheduled during the final 30 days of the project. The purpose of the closeout meeting is to review project performance, the deployment plan, and next steps. Attendees shall include, as a minimum, the project manager, the principal investigator, and the Research Center performance coordinator. This meeting is to occur prior to the expiration of the contract and subsequent to the approval of the draft final report.


IV. Project Kickoff Meeting


 V. Project Schedule


VI. Project Budget

The proposed budget for this project is $95,000.


VII. Equipment

No need for non-standard equipment is expected for conducting the proposed research.


VIII. Travel

No travel will occur on this project.

All travel shall be in accordance with Section 112.061, Florida Statutes. FDOT employees may not travel on research contracts.


IX. Use of Graduate Student(s) and Other Research Assistants

Student assistance is expected to conduct data gathering and analysis under Task 3.


X. Project Team Roles and Responsibilities

Principal Investigator: Sisinnio Concas is the principal investigator for this project. Dr. Concas holds a Ph.D. in Economics from the University of South Florida (USF), and a Doctoral degree in Political Science from the Universitá Degli Studi Di Sassari, Italy. He specializes in urban economics, parametric and nonparametric economic modeling, time series analysis and forecasting, economic impact analysis and public policy analysis. He is a senior research associate at the Center for Urban Transportation Research (CUTR) assigned to the Transportation Program Evaluation & Economic Analysis (TPEEA) team at the College of Engineering at the University of South Florida. As the developer of TRIMMS©, Dr. Concas will head the project from start to finish, including project management, researching, gathering and analyzing data, and writing and editing for this project.

Researcher: Joel Volinski is the director of the National Center for Transit Research (NCTR) program at CUTR. He will provide internal review of the draft final report and oversight throughout the project period, and while his effort is small on this project, his expertise is essential to this project and the program. The budget figure reflects his estimated input for this project.

Researcher: Philip Winters is the director of the TDM program at CUTR. Mr. Winters will participate in the analysis and contribute to the final report for this project.

Program Assistant: Will provide assistance with contract administration including quarterly reporting, layout and editing of the draft final report as well as other programmatic and clerical assistance needed for this project. While OPS, the program assistant is a highly skilled staff member with a wide-range of essential duties. As stated earlier, the annualized salary proposed is a calculation of a part-time hourly rate.

Graduate Research Assistant: a graduate research assistant will perform most of the detailed data analysis of the under Task 3. The graduate student selected will need to be enrolled at the Masters level. College coursework in advanced statistics and data analysis will be needed as they are required for the project work. Again, his or her annualized salary proposed is a calculation of their hourly rate and is competitive with similar graduate students in the college.






National Center for Transit Research · at the Center For Urban Transportation Research · University of South Florida · 4202 E. Fowler Ave., CUT100 · Tampa, FL 33620-5375 · (813) 974-3120 · (813) 974-5168 · · Comments: