Improving Vehicle Activity Data for Project Level Emission Analysis of Specific Transportation Facilities (Short-listed at 2015 TRB)
Research Idea Scope
Note: This research idea was short-listed at the 2015 TRB meeting of the Project-Level Subcommittee of the Transportation and Air Quality Committee (ADC20). The broader research problem to be addressed is the need to improve the vehicle activity data for MOVES-based project level emission analysis. This research problem can be divided into two broad items, namely (1) identify and develop methods to collect local data to more accurately model travel activities at specific transportation facilities (e.g. intersections), vehicle types and emission processes and (2) develop a database-oriented system based on the existing databases to provide the information to the practitioners in an efficient and user-friendly format. Need for improving vehicle activity data with regards to drive cycles or operating mode distributions for specific transportation facilities and critical input parameters is important in light of the recent U.S.EPA’s requirement for PM hot-spot analyses. Practitioners often do not have the time to develop specific drive cycles for each project level analysis. Rather, they depend on MOVES default cycles when performing a hot-spot analysis. This is validated by a study undertaken by FHWA where a survey was conducted of agencies using MOVES to understand their current practices in developing MOVES inputs and needs for additional guidance or sample data inputs. The survey results showed that the large majority of agencies (approximately 92 percent) that are using MOVES reported they are dependent either fully or partially on the MOVES default data to prepare project specific inputs (NCHRP 25-38, 2014). It is important to note that the MOVES database contains only the national average drive cycles. Furthermore, drive cycles with respect to vehicle type (e.g. heavy duty diesel trucks (HDDVs)), certain emission processes (e.g. cold start and idling emissions), and specific transportation facilities (e.g. ramps or intersections) 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. Hence, there is a critical need to improve the MOVES database to support accurate emission estimation especially for project-level analyses that deal with changes in traffic patterns. Objectives related to improving the vehicle activity data for more accurate project level emission estimations are (1) identifying studies that have collected local specific vehicle activity data (such as GPS, Bluetooth, and other data sources) and understanding the technical issues with extracting facility-specific information from them, (2) compiling the available data and performing data quality assessment; (3) extracting and processing the subset of validated facility-specific information for a select set of facility types; and (4) developing a database system to provide the facility-specific vehicle activity information to practitioners. Specific Tasks include: 1. Develop a detailed work plan to improve vehicle activity inputs for MOVES-based project level emission analysis of a select set of facility types 2. Identify studies that have collected real world data corresponding to specific transportation facilities, vehicle types and certain emission processes 3. Evaluate data quality and investigate the technical issues related to extracting facility-specific information for project-level analysis 4. Compile a database of available data, process and quality control the data, extract facility specific data for the desired facility types 5. Develop a database system including methodologies, user interface, and technical guidance to provide the facility-specific drive cycles or operating mode distributions to the practitioners. 6. Document all work in a concise final report.
Urgency and Payoff
Improving vehicle activity data collection at the resolution necessary for project-level analysis and developing a quality-assured database-oriented system based on existing databases will improve the ability of practitioners to efficiently model activity, emissions, and air quality. There is a critical need to improve MOVES database in the light of the recent U.S.EPA’s requirement for hot-spot analyses that focus on specific transportation facilities and vehicle types. Further, as revealed by a recent survey, a majority of agencies depend either fully or partially on the MOVES default database which is know to be deficient for project-level analysis. Funding decisions depend on accurate mobile source emission modeling and a large source of error can result from incorrect representation of travel activity inputs. Improved travel activity inputs that accurately reflect real-world facility-specific driver behavior will increase emissions and air quality prediction accuracy which in turn allows for an improved decision making process.
Reza Farzaneh Texas A&M Transportation Institute 512.407.1118