Evolution of particle number distribution near roadways. Part III: Traffic analysis and on-road size resolved particulate emission factors

K. Max Zhang, Anthony S. Wexler, Debbie A. Niemeier, Fang Zhu Yi, William C. Hinds, Constantinos Sioutas

Research output: Contribution to journalArticle

84 Scopus citations


On-road size-resolved particulate emission factors were computed using concurrently measured carbon monoxide (CO) as a freeway dilution indicator and correlating roadside particle measurements to CO measurements. The emission factors derived for the total particle number agree well with previous on-road investigations. However, this study extends this analysis to produce unique receptor-dependent, size-resolved, road and grid-level emission factor distributions. Both mileage- and fuel-based particle number and mass emission factors at road and grid levels, along with CO emission factors, are presented and the results from freeways with distinctly different percentages of heavy-duty diesel truck traffic are compared. The effects of plume processing on particle number near roadways are shown to be much more profound than on particle mass, further indicting that the adverse health effects observed near roadways are at least partially related to particle numbers.

Original languageEnglish (US)
Pages (from-to)4155-4166
Number of pages12
JournalAtmospheric Environment
Issue number22
StatePublished - Jul 2005



  • Aerosol
  • Carbon monoxide
  • Mobile emissions
  • Traffic
  • Transportation
  • Ultrafine particles

ASJC Scopus subject areas

  • Atmospheric Science
  • Environmental Science(all)
  • Pollution

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