Research and Projects
Houston-Galveston-Brazoria (HGB) and Dallas-Fort Worth (DFW) 2015 Eight-Hour Ozone Standard Nonattainment Areas RFP and VMT Offset On-Road Mobile Emissions Inventories (Ongoing, 2026, $450,000, Role: Task Leader) – The purpose of this project is to develop on-road mobile emissions inventories to support Reasonable Further Progress (RFP) analysis and VMT offset demonstrations for HGB and DFW 2015 eight-hour ozone nonattainment areas. The project develops emissions inventories for HGB six-county and DFW nine-county nonattainment areas using EPA MOVES, latest planning assumptions, local activity data, fuel parameters, I/M program inputs, and control strategy assumptions. Contributed to MOVES input development, emissions inventory processing, control strategy reduction analysis support, output review, and QA/QC for RFP and contingency analysis years.
Heavy Duty Vehicle Idle Activity Study (Ongoing, 2026, Role: Task Leader) – The purpose of this project is to improve heavy-duty vehicle idling activity estimates used in on-road emissions inventories for conformity and SIP applications. The study reviews existing heavy-duty vehicle idling data, evaluates available activity datasets and modeling approaches, and supports improved representation of extended idling activity in MOVES-based emissions modeling. Contributed to literature review, activity data evaluation, MOVES-related methodology assessment, emissions modeling support, and QA/QC of technical findings.
El Paso MPO 2052 Regional Mobility Strategy MTP and 2027–2030 TIP Transportation Conformity PACP Support (Ongoing, 2026, Role: Task Leader) – Supported development and technical review of the El Paso MPO transportation conformity PACP for the 2052 Regional Mobility Strategy MTP and 2027–2030 TIP. Reviewed conformity analysis years, baseline year treatment, travel demand model validation assumptions, regional emissions analysis requirements, MOVES input tables, seasonal and hourly distribution factors, meteorological inputs, I/M inputs, and emissions post-processing procedures. Supported documentation of conformity requirements for PM10, ozone-related NOx and VOC analysis, and interim emissions testing assumptions.
Improving Speed Estimation for Enhanced MOVES On-Road Emissions Modeling in Texas (Ongoing, 2026, $100,000, Role: Assistant Research Scientist) – The purpose of this project is to improve the accuracy and reliability of Texas on-road mobile source emissions estimates by developing locally calibrated MOVES speed-bin distributions from probe-based traffic speed data, such as INRIX, HERE, and Replica. The project evaluates how observed speed data can better capture congestion patterns, time-of-day variation, and real-world driving conditions for use in MOVES emissions modeling. Responsible for literature review, speed model development, case study application, model validation, evaluation, integration, and QA/QC.
Virtual Link Method Review, Refinement, and Update (Ongoing, 2026, $150,000, Role: Assistant Research Scientist)– The purpose of this project is to review and enhance TTI’s virtual link emissions inventory development method to improve speed estimation accuracy and spatial resolution for on-road emissions inventories used in Texas SIP development. The project reviews the existing HPMS-based virtual link method, evaluates opportunities to incorporate statewide transportation networks, assesses alternative volume-delay functions, and develops updated procedures for emissions inventory and photochemical modeling applications. Contributed to literature and method review, validation framework development, data source assessment, MOVES comparison design, QA/QC planning, and documentation.
Improved Methodology for Vehicle Start Activity (Ongoing, 2026, $100,000, Role: Assistant Research Scientist) – The purpose of this project is to develop a more accurate methodology for estimating vehicle start activity using local, high-resolution data sources. The project addresses limitations in current MOVES default assumptions for spatially and temporally allocating start emissions, particularly where vehicles travel across county boundaries for work, school, shopping, and other activities. Contributed to literature review, vehicle start activity data assessment, methodology development, county-to-county travel data evaluation, emissions impact analysis support, and QA/QC documentation.
Monitoring and Speciation of Particulate Matter Under 2.5 Microns (PM2.5) Composition across Texas Counties (Ongoing, 2026, $750,000, Role: Data Analyst) – Texas needs a more detailed understanding of statewide fine particulate matter (PM2.5) sources because current regulatory monitoring does not provide sufficient spatial or chemical detail for robust source apportionment. Because speciated PM2.5 data are limited, the TTI, in collaboration with TSU and TAMU, research team is conducting a statewide effort that includes PM2.5 sample collection, chemical speciation, and source apportionment to identify the dominant PM2.5 contributors by region. Results will support future research and regulatory actions, including the development and implementation of targeted emission-reduction strategies.
The Effects of Road Types and Construction Activities on Particulate Matter and Development of Best Practices for PM2.5 Reduction (Ongoing, 2026, $700,000, Role: Data Analyst) – The TTI (in association with TSU and TAMU) study team will provide TxDOT with a practical framework to quantify and reduce PM2.5 through measures such as paving unpaved roads near sensitive receptors, optimizing road shoulder widths, and strengthening dust-suppression practices at construction sites. The goal is to develop measurable, actionable solutions to reduce PM2.5 concentrations associated with roadway and construction operations.
Development of Statewide On-Road Emissions Inventories for 2022 and 2032 (Completed, 2025, $250,000, Role: Task Leader) – The purpose of this project was to develop statewide on-road emissions inventories for calendar years 2022 and 2032 to support TCEQ air quality modeling and future SIP planning efforts. For all 254 Texas counties, emissions inventories were developed based on HPMS-based VMT activity estimates from TxDOT and EPA’s MOVES5 model. Contributed to data collection, processing, protocol and parameter development, emissions inventory preparation, documentation, and QA/QC of model inputs and outputs.
Development of Houston-Galveston-Brazoria (HGB), Dallas-Fort Worth (DFW), and San Antonio (SAN) Emissions Inventories for 2022 and 2032 (Completed, 2025, Role: Task Leader) – The purpose of this project was to develop link-based on-road emissions inventories for the HGB, DFW, and SAN areas for calendar years 2022 and 2032 as air quality modeling inputs. The inventories were developed using VMT activity estimates from local travel demand models for the eight-county HGB area, twelve-county DFW area, and five-county SAN area. Contributed to data collection, processing, emissions inventory protocol and parameter development, MOVES input preparation, output processing, documentation, and QA/QC.
Development of Ozone Season Link-Based On-Road Emissions Inventories for HGB, DFW, and SAN for 2029 (Completed, 2025, $180,000, Role: Task Leader) – The purpose of this project was to develop 2029 ozone-season link-based on-road emissions inventories for the HGB, DFW, and SAN metropolitan areas to support future SIP attainment demonstration modeling under the 2015 eight-hour ozone standard. The project developed inventories based on VMT activity estimates from regional travel demand models, including H-GAC, NCTCOG, and Alamo Area MPO data sources. Contributed to MOVES input development, local activity data processing, emissions inventory generation, electronic data file preparation, documentation, and QA/QC.
Updated On-Road Trend Emissions Inventories (Completed, 2025, Role: Task Leader) – The purpose of this project was to update on-road trend emissions inventories for Texas air quality planning applications using available transportation activity data, MOVES emissions modeling inputs, and regulatory inventory development methods. Contributed to emission inventory input development, activity and emissions estimation, inventory summarization, XML file development, QA/QC analysis, and documentation.
Development of Emission Rate Look-up Tables (completed, 2025, 280,000, Role: Data Analyst) – The project team developed a new set of Emission Rate Look-Up Tables (ERLTs) using EPA’s MOVES5 model. The ERLTs included air pollutants (CAP), mobile source air toxics (MSATs), and greenhouse gases (GHGs).
Development of Texas On-Road Mobile 2023 Air Emissions Reporting Requirements Emissions Inventory (Completed, 2024, Role: Task Leader) – The purpose of this project was to develop the on-road mobile source portion of Texas’ 2023 Air Emissions Reporting Requirements (AERR) emissions inventory and MOVES county databases for submittal to EPA in support of the National Emissions Inventory (NEI). The project included development of annual, summer work weekday, and winter work weekday emissions inventories and MOVES CDBs for all Texas counties, as well as inputs for the TCEQ Texas Road Dust Calculator. Contributed to development of factors, emissions rates, activity and emissions estimation, model input/output processing, and QA/QC analysis.
El Paso County Nonattainment Area Reasonable Further Progress On-Road Mobile Emissions Inventories (Completed, 2024, Role: Task Leader) – The purpose of this project was to develop on-road mobile emissions inventories necessary to support the El Paso County RFP SIP revision for the 2015 eight-hour ozone NAAQS. The project produced link-based emissions inventories for the El Paso County ozone nonattainment area for analysis years 2017, 2023, and 2024. Contributed to data collection, processing, protocol and parameter development, emissions inventory preparation, documentation, and QA/QC.
Development of HGB, DFW, and Statewide On-Road Emissions Inventories for 2019 and 2026, and On-Road Activity Data for 2022 (Completed, 2024, Role: Task Leader) – The purpose of this project was to develop on-road emissions inventories for calendar years 2019 and 2026 and on-road activity data for 2022 to support TCEQ air quality modeling applications. The project included 2022 HPMS-based VMT by MOVES source type, 2019 and 2026 link-based emissions inventories for eight HGB counties, 2019 and 2026 link-based emissions inventories for twelve DFW counties, and 2019 and 2026 HPMS-based inventories for all 254 Texas counties. Contributed to development of factors, emission rates, activity and emissions estimation, model input/output processing, and QA/QC analysis.
Houston-Galveston-Brazoria (HGB), DFW, and Bexar County Nonattainment Areas Reasonable Further Progress (RFP) On-Road Mobile Emissions Inventories (Completed, 2023, $400,000, Role: Data Analyst) – The purpose of this study is to develop and produce on-road mobile EI necessary to support the HGB-area, DFW-area, and Bexar County RFP SIP revisions for the 2008 and 2015 eight-hour ozone National Ambient Air Quality Standard (NAAQS). Specifically, for the 2015 eight-hour ozone NAAQS, TTI will develop and produce on-road mobile link-based EI for the six HGB ozone nonattainment counties, the nine DFW ozone nonattainment counties, and the Bexar County ozone nonattainment area for analysis years 2017, 2023, 2024, 2026, and 2027. For the 2008 eight-hour ozone NAAQS, TTI will develop on-road mobile link-based EI for the ten DFW ozone nonattainment counties for analysis years 2026 and 2027.
Development of San Antonio (SAN) On-Roa Emissions Inventories for 2026 (Completed, 2023, $65,000, Role: Data Analyst) – The purpose of this study is to develop on-road emission inventories that will be used as air quality modeling inputs for the 2026 calendar year. For the five counties within the San Antonio metropolitan area (SAN), link-based on-road emission inventories will be developed based on vehicle miles traveled (VMT) and activity estimates from the local travel demand model (TDM).
El Paso (ELP) County Nonattainment Area RFP On-Road Mobile Emissions Inventories (Completed, 2023, $100,000, Role: Data Analyst) – The purpose of this study is to develop and produce on-road mobile EI necessary to support the ELP County RFP SIP revision for the 2015 eight-hour ozone NAAQS. Specifically, the Grantee shall develop and produce on-road mobile link-based EI for the ELP County ozone nonattainment area for analysis years 2017, 2023, and 2024.
On-Road Emissions Inventory Development (Completed, 2023, $110,000, Role: Data Analyst) – This project aims to conduct emissions inventory development and air monitoring related to ground-level ozone (O3) for the Austin-Round Rock-Georgetown Metropolitan Statistical Area (MSA) (Bastrop, Caldwell, Hays, Travis, and Williamson Counties).
On-road Mobile Air Emissions Reporting Requirement (AERR) Methodology Assessment and Input Sensitivities (Ongoing, 2023, $100,000, Role: Data Analyst) – The purpose of this project is to assess and improve the development process and identify data sources for required AERR MOVES inventory mode county databases (CDBs). This will require the TTI to perform a thorough review of the regulatory requirements and associated guidance documents. Additionally, the Grantee shall perform a sensitivity assessment to determine the MOVES activity input parameters with the greatest effect on emissions by assessing the recently completed 2020 AERR on-road modeling files and the MOVES trend information being developed as part of a separate project. This project will also assess the suitability of using MOVES default modeling parameters developed by the EPA in place of Texas-specific activity data.
Modeling Electric Vehicle Impacts on Air Quality (Completed, 2023, $150,000, Role: Data Analyst) – The goal of this study was to evaluate the impact of future PEV scenarios on the regional ozone levels for the metropolitan areas in Texas. The study focused on characterizing the complex interactions between PEVs’ population, vehicle activities, charging behavior, electricity generation mix, energy consumption and emissions, and their impact on ozone levels at a regional scale.
Research and Data Gathering of Port Emissions and Reduction Strategies (Completed, 2023, $75,000, Role: Data Analyst) – The purpose of this project was to research emissions reduction strategies including incentive/grant programs, voluntary programs, and regulatory measures that have been successfully implemented at various ports. The Grantee shall use the data gathered to quantify a range of potential emissions reductions for the recommended measure identified, cost, approximate timeline to implement, and any potential cost savings for vessel owners or ports.
Development of International Border Crossing (IBC) Emissions Tool (Completed, 2022, $170,000, Role: Data Analyst) – This project aims to develop a module/add-in that can be invoked in the TransModeler environment to format the trajectory outputs and estimate emissions on the IBC network links. While the focus of this project will be on ozone precursors (NOx and VOCs), TTI will also develop the module for estimating other criteria pollutant emissions (CO, PM2.5, and PM10) as well as greenhouse gases (CO2 equivalents).
Improvement of Locomotive and Rail Yard Activity Data Sourcing and Accuracy Project (Completed, 2022, $150,000, Role: Data Analyst) – This project aimed at streamlining and improving the development of locomotive and rail yard source EI (EI) by exploring and assessing various open-source data sets, such as freight analysis framework (FAF) data, to provide additional potential resources for obtaining activity data such as fuel usage and fleet-mix data. This project also included the development of an updated Texas-specific fleet mix by Class I, Class III, Class I yard, Class III yard, rail network industrial leads, commuter, and passenger operators and improved emissions inventory of switching yard sources, including those located in critical nonattainment areas, through various comprehensive data mining efforts.
Statewide 254 County On-Road Mobile 2020 Air Emissions Reporting Requirements and Hazardous Air Pollutants Inventory (Completed 2022, $150,000, Role: Data Analyst) – The deliverables of this project provided the requisite on-road mobile source portion of the 2020 periodic year EI and CDBs for all 254 Texas counties. The State of Texas is required to submit periodic EI and the EPA MOVES CDBs under the AERR to support the EPA’s comprehensive three-year cycle National Emissions Inventory (NEI).