Modeling Microscale Real-World Vehicle Emissions

Modeling Methods for Accurate Estimation of Real-World Vehicle Emissions

Dr. Frey’s research developed and refined modeling methodologies for predicting vehicle emissions with a high degree of temporal and spatial resolution. These papers advanced the state-of-the-art in modal emissions modeling, which uses instantaneous vehicle operating parameters to predict emissions. The work includes the development of simplified models that can be coupled with traffic simulation software, enabling the efficient evaluation of emission impacts from large-scale traffic management strategies and infrastructure changes. These types of models are essential tools for government agencies and planners.

Illustrative papers (selected examples): 

Micro-Scale Emissions Modeling:  Vehicle-Based

Silva, C.M, T.L. Farias, H.C. Frey, and N.M. Rouphail, “Evaluation of Numerical Models for Simulation of Real-World Hot-Stabilized Fuel Consumption and Emissions of Gasoline Light-Duty Vehicles.” Transportation Research Part D, 11(5):377-385 (2006).

Frey, H.C., K. Zhang, and N.M. Rouphail, “Vehicle-Specific Emissions Modeling Based Upon On-Road Measurements,” Environmental Science and Technology, 44(9):3594-3600 (2010).

Zhai, H., H.C. Frey, and N.M. Rouphail, “Development of A Modal Emissions Model for A Hybrid Electric Vehicle,” Transportation Research – Part D.  16(6):444-450 (August 2011).

Hu, J., H.C. Frey, and S.S. Washburn, “Comparison of Vehicle-Specific Fuel Use and Emissions Models Based on Externally and Internally Observable Activity Data,” Transportation Research Record, 2570:30-38 (2016).

Wei, T., and H.C. Frey, “Evaluation of the Precision and Accuracy of Cycle Average Light Duty Gasoline Vehicles Tailpipe Emission Rates Predicted by Modal Models,” Transportation Research Record, 2674(7):566-584 (2020).  https://doi.org/10.1177/0361198120924006

Micro-Scale Emissions Modeling:  Infrastructure-Based

Salamati, K., M. Coelho, P. Fernandes, N.M. Rouphail, H.C. Frey and J. Bandeira, “Emission Estimation at Multilane Roundabouts: Effect of Movement and Approach Lane,” Transportation Research Record, 2389:12-21 (March 2013).

Salamati, K., N.M. Rouphail, H.C. Frey, B. Liu, and B.J. Schroeder, “A Simplified Method for Comparing Emissions at Roundabouts and Signalized Intersections,” Transportation Research Record, 2517:48-60.  DOI: 10.3141/2517-06. (2015)

Fleet-Scale Emissions Modeling

Frey, H.C., H. Zhai, and N.M. Rouphail, “Regional On-Road Vehicle Running Emissions Modeling and Evaluation for Conventional and Alternative Vehicle Technologies,” Environmental Science and Technology, 43(21):8449–8455 (doi: 10.1021/es900535s, published online Sept 22, 2009).

Anya, A.R., N.M. Rouphail, H.C. Frey, and B. Schroeder, “Application of AIMSUN Micro Simulation Model in Estimating Emissions on Signalized Arterial Corridors,” Transportation Research Record, 2428(2):75-86 (2014).

Zhou, X., S. Tanvir, H. Lei, J. Taylor, B. Liu, N.M. Rouphail, and H.C. Frey, “Integrating a Simplified Emission Estimation Model and Mesoscopic Dynamic Traffic Simulator to Efficiently Evaluate Emission Impacts of Traffic Management Strategies,” Transportation Research – Part D, 37(2015):123-136.

Model Applications:  Vehicle, Routing, and Driving Cycles

Wei, T., and H.C. Frey, “Intermodal comparison of tailpipe emission rates between transit buses and private vehicles for on-road passenger transport,” Atmospheric Environment, Available online 30 April 2022, 119141, https://doi.org/10.1016/j.atmosenv.2022.119141.

Yuan, W., H.C. Frey, T. Wei, “Fuel use and emission rates reduction potential for light-duty gasoline vehicle eco-driving,” Transportation Research Part D: Transport and Environment, 109, August 2022, 103394.  https://doi.org/10.1016/j.trd.2022.103394