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Quantifying on-road Emission Factors Using Mobile Platforms

The transportation sector consumes 21 percent of primary energy and account for 20 percent of greenhouse emissions worldwide. In recent years, studies across the world have reported that human exposure to traffic-related air pollutants are associated with a range of health effects. The challenges facing the transportation sector are especially daunting for fast growing economies in Asia, which have been undergoing motorization at a pace unprecedented in human development. Accurate assessment of mobile emissions is key to developing effective energy and environmental policies on the transportation sector.

Researchers at EERL have been developing and refining methodologies on quantifying on-road emissions using mobile platforms since 2004. We have demonstrated a cost effective approach to characterize the emissions from a large number of on-road vehicles, which are critical to constructing more accurate mobile emission inventories to represent the on-road vehicle population.

  • 2004-2006: Designed the mobile platform measuring on-road, community, and airport air quality 1,2
  • 2005: Derived, for the first time, the size-resolved on-road particulate emission factors 3
  • 2007: Measured fleet average on-road emission factors for cars and trucks in Beijing using mobile platform4
  • 2008: Measured fleet average and some individual emission factors for cars, trucks, and buses before and during 2008 Beijing Olympics Games using mobile platform 5
  • 2009: Measured individual emission factors for 230 trucks and 57 buses in and around Beijing within one week, for both cruise and transient conditions using mobile platform 6
  • 2010: Measured individual NOx and black carbon emission factors of over 440 trucks in Beijing and Chongqing. Showed the ineffectiveness of NOx emission controls for on-road diesel trucks in China7
Graph

EF distributions (a: CO; b: BC; c: PM0.5 number; d: PM0.5 mass) and cumulative distribution of truck emission (e) reported in Wang et al. (2010) 6

Related Publications

  1. Westerdahl et al. (2005) Mobile platform measurements of ultrafine particles and associated pollutant concentrations on freeways and residential streets in Los Angeles. Atmospheric Environment 2005, 39, (20), 3597-3610. [PDF]
  2. Westerdahl et al. (2008) The Los Angeles International Airport as a source of ultrafine particles and other pollutants to nearby communities. Atmospheric Environment 2008, 42, (13), 3143-3155. [PDF]
  3. Zhang et al., (2005) Evolution of particle number distributions near roadways Part III: Traffic analysis and on-road size resolved particulate emission factors. Atmospheric Environment 2005, 39, (22), 4155-4166. [PDF]
  4. Westerdahl et al. (2009) Characterization of on-road vehicle emission factors and microenvironmental air quality in Beijing, China. Atmospheric Environment 2009, 43, (3), 697-705. [PDF]
  5. Wang et al., (2009) Evaluating the Air Quality Impacts of the 2008 Beijing Olympic Games: On-road Emission Factors and Black Carbon Profiles. Atmospheric Environment 2009, 43, 4535–4543. [PDF]
  6. Wang et al., (2011) On-road emission factor distributions of individual diesel vehicles in and around Beijing, China. Atmospheric Environment 2011, 45(2), 503-513 [PDF]
  7. Wang, X., et al.(2012) On-road diesel vehicle emission factors for nitrogen oxides and black carbon in two Chinese cities. Atmospheric Environment 2012, 46(1), 45-55 [PDF]