SWUTC Research Project Description
Texas-Specific Drive Cycles and Idle Emissions Rates for Using with EPA’s MOVES Model
University: Texas A&M University
Principal Investigator:
Reza Farzaneh
Texas Transportation Institute
(512) 467-0946
Funding Source: SPR Program
Total Project Cost: $152,442
Project Number: 0-6629
Date Started: 9/1/12
Estimated Completion Date: 8/31/13
Project Summary
Project Abstract:
The U.S. Environmental Protection Agency’s (EPA) newest emissions model, MOtor Vehicle Emission Simulator (MOVES), utilizes a disaggregate approach that enables the users of the model to create and use local drive schedules (drive cycles) in order to perform an accurate analysis. However, only the national average drive schedules are currently included in the default database of the model. Furthermore, the cold start and idling emissions and activity data of heavy duty diesel trucks (HDDVs) that are included in the MOVES model are based on a very limited number of data sources even though they are very important components of the total on-road mobile source emissions inventory. This study will provide the Texas Department of Transportation (TxDOT) with local drive cycles for different regions of Texas for different vehicle classes and roadway types as well as cold start and idling emissions rates for heavy-duty diesel trucks. The estimated emissions from MOVES for different vehicle classes will be compared to real-world on-road emissions measurement. Furthermore, the technical and tactical issues of integrating the results of this study into MOVES for formal emissions analyses purposes will be investigated and recommendations will be made based on the findings. The project will also be of great benefit to TxDOT divisions and other agencies such the EPA and Texas Commission on Environmental Quality (TCEQ).
Project Objectives:
The objective of this work is to develop a detailed data collection protocol that will involve vehicle selection for each phase, drive schedule (i.e. drive cycles as they are called in MOVES) and vehicle activity data collection procedures, and emissions testing utilizing sophisticated PEMS and other equipment including TTI’s environmental chamber. A suite of technologies including global positioning system (GPS) and engine data loggers will be utilized for drive schedule and vehicle activity data collection. TTI’s state-of-the-art PEMS equipment (most complete in Texas) will be used to characterize the cold start and idling emissions of the selected HDDVs’ under controlled conditions. In addition, TTI’s DEKATI-DMM unit that measures PM mass and filter cartridges will be collected during the cold start and idling testing and sent to the Oak Ridge National Laboratory (ORNL) for PM and MSAT analysis.
Task Descriptions:
Task 1: State-of-the-Practice and Available Texas Emissions and Vehicle Activity Data
Task 2: Data Collection Protocol Development
Task 3: Selection of Vehicles and Study Areas
Task 4: Vehicle Recruiting
Task 5: Drive Schedule Data Collection
Task 6: Development of Texas-Specific Drive Schedules
Task 7: Cold Start and Idling Emissions Measurement and Analysis
Task 8: Compare MOVES Results with In-Use Results
Task 9: Integration of Results into MOVES
Task 10: Prepare Project Documentation
Implementation of Research Outcomes:
The U.S. Environmental Protection Agency’s newest emissions model, Motor Vehicle Emission Simulator (MOVES), enables users to use local drive schedules (representative vehicle speed profiles) in order to perform an accurate analysis of emissions from vehicles. However, only the national average drive schedules are currently included in the default database of the model. The cold start and idling emissions and activity data of heavy-duty diesel vehicles (HDDVs) that are included in the MOVES model are based on a very limited number of data sources, even though they are important components of the total on-road mobile source emissions inventory.
This research provides local drive schedules for different regions of Texas for different vehicle classes and roadway types, as well as cold start and idling emissions rates for heavy-duty diesel trucks. The research also compares estimated emissions from MOVES for a sample of vehicles to real-world in-use emissions measurements.
Impacts/Benefits of Implementation:
The results of this research, impacting the USDOT goal of environmental sustainability, determined that different regions of Texas can use local drive schedules in their regional air quality analyses. The first step in this process is to obtain the approval of the consultative partners.
Cold-start emissions are usually higher than re-start emissions for intervening soak times of up to 59 minutes.
Trucks with California Air Resources Board clean idling stickers do not always meet the 30 g/h NOx emissions threshold during idling under real-world conditions.
The idling emissions data indicate that the emissions control technologies that are currently used to reduce NOx from diesel trucks are not as effective in idling conditions.
Web Links:
Final Technical Report