Capturing the Uncertainties in Regional Emission Estimates Related to Vehicle Electrification Can Improve the Robustness of Decision-Making

Many sources of uncertainty exist in current traffic emission modelling tools, which trickle into regional transportation emission inventories. They are ever more pertinent today as urban transportation systems are going through drastic changes. This study presents a greenhouse gas (GHG) emission modelling tool for transportation, which considers various sources of uncertainty in the emission modelling process. It was used to estimate well-to-wheel (WTW) emission distributions for internal combustion engine vehicles (ICEV) and electric vehicles (EV) in the Toronto region. Other than base cases with only ICEV, scenarios with 5% and 30% EV penetration were also developed to investigate the mixed effects of vehicle electrification and well-to-pump (WTP) emission uncertainty. The authors observed base cases for the study years 2011 and 2017 has mean values of transportation GHG emissions of 32,800 and 28,500 metric ton CO₂e, respectively. With the introduction of EVs, they noticed no significant GHG reduction in 5% EV scenarios. A 30% EV penetration rate led to a mean regional estimate of 23,500 metric ton CO₂e in 2011 and 20,400 metric ton CO₂e in 2017. The authors found a wider distribution of possible regional emissions in 2017 due to a wider range in gasoline production emission factors. Significant overlap in the distribution of total emissions was obtained between base cases and the 5% EV penetration cases. This indicates that the GHG reduction effect of EVs at a small penetration rate is possibly less significant than the effect of uncertainty in the emission modelling process and ICEV emission reduction technology.

• Supplemental Notes:
  • This paper was sponsored by TRB committee ADC20 Standing Committee on Transportation and Air Quality.
• Corporate Authors:

  Transportation Research Board

  ,    
• Authors:
  • Wang, An
  • Tu, Ran
  • Gai, Yijun
  • Pereira, Lucas G
  • Posen, I Daniel
  • Hatzopoulou, Marianne
• Conference:
  • Transportation Research Board 98th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2019-1-13 to 2019-1-17
• Date: 2019

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 19p

Subject/Index Terms

• TRT Terms: Decision making; Electric vehicles; Exhaust gases; Greenhouse gases; Internal combustion engines; Market penetration; Monte Carlo method; Uncertainty; Urban transportation policy
• Subject Areas: Environment; Highways; Planning and Forecasting; Policy; Vehicles and Equipment;

Filing Info

• Accession Number: 01698064
• Record Type: Publication
• Report/Paper Numbers: 19-04153
• Files: TRIS, TRB, ATRI
• Created Date: Mar 1 2019 3:51PM