Causal Effects of the Abolition of London Western Charging Zone on Vehicle Emissions: A Regression Discontinuity Study

This paper applies the regression discontinuity (RD) method to evaluate the effects of removing the London western charging zone (WCZ) on traffic flow and vehicle emissions. A total of 525 road sections are included for a period of 3 years (2008, 2010, and 2013). The authors first test the continuity of the confounders, and the results show that all confounders are continuous at the cutoff. Then the effects of implementing and removing the western charging zone scheme are estimated respectively. The results suggest that the AADT is reduced by about 31.1% within the western zone after implementing the WCZ scheme. On the contrary, without expansive congestion fees after calling off the WCZ, the number of vehicles within the western zone is increased by around 26.4%. Regarding the effects of the WCZ scheme on the emissions of vehicles, the results indicate that the vehicle emission of NOX and CO2 is decreased by around 29% and 33% respectively within western charging zone. In contrast, the emission of NOX and CO2 is increased by 24% and 21% respectively after removing the WCZ. After controlling for the time trend effect, the results indicate that there are residual effects of the WCZ on AADT and the vehicle emission of CO2 (AADT: 4,412 versus 3,011, Time trend: −1,100; CO2: 134 μg/m3 versus 70 μg/m3, Time trend: −30 μg/m3). However, such a residual effect on the vehicle emission of NOX is not significant.

• Record URL:
  • https://doi.org/10.1061/9780784483053.226
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9780784483053
• Supplemental Notes:
  • © 2020 American Society of Civil Engineers.
• Corporate Authors:

  American Society of Civil Engineers

  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Li, Haojie
  • Ding, Hongliang
• Conference:
  • 20th COTA International Conference of Transportation Professionals
  • Location: Xi’an , China
  • Date: 2020-8-14 to 2020-8-16
• Publication Date: 2020

Language

• English

Media Info

• Media Type: Web
• Features: References;
• Pagination: pp 2681-2692
• Monograph Title: CICTP 2020: Transportation Evolution Impacting Future Mobility

Subject/Index Terms

• TRT Terms: Exhaust gases; Nitrogen oxides; Road pricing; Time series analysis; Traffic flow
• Geographic Terms: London (England)
• Subject Areas: Environment; Highways; Vehicles and Equipment;

Filing Info

• Accession Number: 01768180
• Record Type: Publication
• ISBN: 9780784483053
• Files: TRIS, ASCE
• Created Date: Mar 25 2021 9:35AM