Estimating Emissions from Static Traffic Models: Problems and Solutions

In large urban areas, the estimation of vehicular traffic emissions is commonly based on the outputs of transport planning models, such as Static Traffic Assignment (STA) models. However, such models, being used in a strategic context, imply some important simplifications regarding the variation of traffic conditions, and their outputs are heavily aggregated in time. In addition, dynamic traffic flow phenomena, such as queue spillback, cannot be captured, leading to inaccurate modelling of congestion. As congestion is strongly correlated with increased emission rates, using STA may lead to unreliable emission estimations. The first objective of this paper is to identify the errors that STA models introduce into an emission estimation. Then, considering the type and the nature of the errors, the aim is to suggest potential solutions. According to the findings, the main errors are related to STA inability of accurately modelling the level and the location of congestion. For this reason, the authors suggest and evaluate the postprocessing of STA outputs through quasidynamic network loading. Then, the authors evaluate the suggested approach using the HBEFA emission factors and a 19km long motorway segment in Stockholm as a case study. Although, in terms of total emissions, the differences compared to the simple static case are not so vital, the postprocessor performs better regarding the spatial distribution of emissions. Considering the location-specific effects of traffic emissions, the latter may lead to substantial improvements in applications of emission modelling such as dispersion, air quality, and exposure modelling.

• Record URL:
  https://doi.org/10.1155/2020/5401792
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/5121625
• Supplemental Notes:
  • ©2020 Nikolaos Tsanakas, Joakim Ekstrom, and Johan Olstam.
• Authors:
  • Tsanakas, Nikolaos
  • Ekström, Joakim
  • Olstam, Johan
• Publication Date: 2020-2

Language

• English

Media Info

• Media Type: Web
• Features: Figures; Maps; References; Tables;
• Pagination: 17p
• Serial:
  • Journal of Advanced Transportation
  • Volume: 2020
  • Issue Number: Content ID 5401792
  • Publisher: John Wiley & Sons, Incorporated
  • ISSN: 0197-6729
  • EISSN: 2042-3195
  • Serial URL: http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)2042-3195
• Publication flags:

  Open Access (libre)

Subject/Index Terms

• TRT Terms: Environmental risk assessment; Estimating; Exhaust gases; Traffic assignment; Traffic congestion; Traffic flow; Traffic models
• Geographic Terms: Stockholm (Sweden)
• Subject Areas: Environment; Highways; Planning and Forecasting;

Filing Info

• Accession Number: 01737904
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 27 2020 9:07AM