This project has two objectives:
1. Develop methods to modify traditional planning networks for use in TRANSIMS
2. Develop methods to combine the TRANSIMS emissions model with EPA's Mobile6 for emissions analysis.
Network simulations produce information on a second-second basis for 7.5 meter segments of highway. The current emission models require information on an hourly basis by link. This project will investigate methods to aggregate network simulations to become input to Mobile 6, and methods to combine results of the TRANSIMS emissions model with Mobile6. This takes advantage of the TRANSIMS capability to analyze the effect of changes in traffic operations on emissions and of the Mobile 6 capability to analyze the effect of vehicle technology changes on emissions. EPA is a funding partner for this project. The project will use the current Portland travel forecasting network along with existing trip tables, converted to TRANSIMS format, for analysis.
The first task will be to identify aggregation levels of simulation output and compare model sensitivities to the different aggregation levels.
The second task will examine model sensitivities to various vehicle operating conditions.
The third task will develop approaches for integrating simulated emissions with MOBILE6 estimates.
The final task of this project will develop guidance materials for practitioners.
Current Status: We have completed initial traffic assignments and have developed methods to aggregate results for input to Mobile6. Initial runs of TRANSIMS with Mobile6 have demonstrated that aggregation methods will influence emissions estimates. We have also developed prelimiary recommendations on the most appropriate method to use TRANSIMS and Mobile6 for Emissions Analysis. We have encountered an issue of too many lost vehicles in the microsimulator. We are making corrections to the microsimulator and will resume when they are complete.
Evaluate the sensitivities of emission models; Identify strategies for normalizing non-regulatory models with regulatory models; Develop guidance on using TRANSIMS and other simulation models for emissions analysis.
Ducca
Ongoing