Investigating the real-world emission characteristics of light-duty gasoline vehicles and their relationship to local socioeconomic conditions in three communities in Los Angeles, California

Park, Seong Suk; Vijayan, Abhilash; Mara, Steve; Herner, Jorn

doi:10.1080/10962247.2016.1197166

Cited by 20 publications

(11 citation statements)

References 19 publications

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“…Both the 1989 and 1991 Lynwood measurements found a vehicle fleet that was higher emitting and much older than other sites visited within the Basin. Since those measurements the only reported measurements from the South Los Angeles area fleet were chased car measurements from 113 vehicles in 2010 which again showed an older and higher emitting fleet (Park et al 2016). Because average fleet age can often be correlated with income, it was not too surprising that median household incomes determined using owner registration zip codes from the 1991 measurements collected on Long Beach Blvd.…”

Section: Introductionmentioning

confidence: 99%

Three decades of on-road mobile source emissions reductions in South Los Angeles

Bishop

2019

Journal of the Air & Waste Management Association

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In May 2018, the University of Denver repeated on-road optical remote sensing measurements at two locations in Lynwood, CA. Lynwood area vehicle tailpipe emissions were first surveyed in 1989 and 1991 because the area suffered from a large number of carbon monoxide (CO) air quality violations. These new measurements allow for the estimation of fuel-specific CO and total hydrocarbon (HC) emissions reductions, changes in the longevity of emission-control components, and the prevalence of high emitters in the current fleet. Since 1989 CO emissions decreased approximately factors of 10 (120 ± 8 to 12.3 ± 0.2 gCO/kg of fuel) and 20 (210 ± 8 to 10.4 ± 0.4 gCO/kg of fuel) at our I-710/Imperial Highway and Long Beach Blvd. sites, respectively. These reductions are also reflected in the local ambient air measurements. Tailpipe HC emissions have decreased by a factor of 25 (50 ± 4 to 2.1 ± 0.3 gHC/kg of fuel) since 1991 at the Long Beach Blvd. location. The decreases are so dramatic that the vast majority of vehicles now have HC measurements that are indistinguishable from zero. The decreases have increased the skewedness of the emissions distribution with the 99th percentile now responsible for more than 37% (CO) and 28% (HC) of the totals. Ammonia emissions collected in 2018 at both Lynwood locations peak with 20-year-old vehicles (1998 models), indicating long lifetimes for catalytic converters. In 1989 and 1991, the on-road Lynwood fleets had significantly higher emissions than fleets observed in other locations within the South Coast Air Basin. The 2018 fleets now have means and emissions by model year that are consistent with those observed at other sites in Los Angeles and the U.S. This indicates that modern vehicle combustion management and after-treatment systems are achieving their goals regardless of community income levels. Implications: Recent on-road vehicle emission measurements at two locations in the Lynwood, CA area, first visited in 1989, found significant fuel specific CO and HC emission reductions. CO emissions have decreased by a factor of 10 and 20 at each location and HC emissions have declined by a factor of 25. This has increased the skewedness in both species emissions distribution. The 2018 fleets have means and emissions by model year that are now consistent with those observed at other U.S. sites indicating that modern vehicle emissions control advancements are achieving their goals regardless of community income levels.

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Section: Introductionmentioning

confidence: 99%

Three decades of on-road mobile source emissions reductions in South Los Angeles

Bishop

2019

Journal of the Air & Waste Management Association

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“…To effectively capture emissions from sub-sector processes, models are also reliant on emissions factor models, such as the EMFAC2017 emissions model used in this paper. While our measurements largely agreed with the EMFAC2017 emissions model for CO2, plume-based emission factor measurements of co-emitted pollutants (CO, NOx, PM2.5, BC, (Bishop, 2021), fail to capture spatial heterogeneity in these factors due to fleet composition (age and compliance with control technologies) for PM (Haugen & Bishop, 2018;Park, Vijayan, Mara, & Herner, 2016) and Black Carbon (Preble, Cados, Harley, & Kirchstetter, 2018), or fail to capture the impact of temperature on emissions factors.…”

Section: Discussionmentioning

confidence: 61%

Assessing vehicle fuel efficiency using a dense network of CO<sub>2</sub> observations

Fitzmaurice

Turner

Kim

et al. 2021

Preprint

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Abstract. Transportation represents the largest sector of anthropogenic CO2 emissions in urban areas. Timely reductions in urban transportation emissions are critical to reaching climate goals set by international treaties, national policies, and local governments. Transportation emissions also remain one of the largest contributors to both poor air quality (AQ) and to inequities in AQ exposure. As municipal and regional governments create policy targeted at reducing transportation emissions, the ability to evaluate the efficacy of such emission reduction strategies at the spatial and temporal scales of neighborhoods is increasingly important. However, the current state of the art in emissions monitoring does not provide the temporal, sectoral, or spatial resolution necessary to track changes in emissions and provide feedback on the efficacy of such policies at a neighborhood scale. The BErkeley Air Quality and CO2 Network (BEACO2N) has previously been shown to provide constraints on emissions from the vehicle sector in aggregate over a ~1300 km2 multi-city spatial domain. Here, we focus on a 5 km, high volume, stretch of highway in the SF Bay area. We show that inversion of the BEACO2N measurements can be used to understand two factors that affect fuel efficiency: vehicle speed and fleet composition. The CO2 emission rate of the average vehicle (g/vkm) are shown to vary by as much as 27 % at different times of a typical weekday because of changes in vehicle speed and fleet composition. The BEACO2N-derived emissions estimates are consistent to within ~3 % of estimates derived from publicly available measures of vehicle type, number, and speed, providing direct observational support for the accuracy of the Emissions FACtor model (EMFAC) of vehicle fuel efficiency.

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“…To effectively capture emissions from sub-sector processes, models are also reliant on emissions factor models, NMHC) show various emissions factor models to systematically underestimate emissions factors (Bishop, 2021), fail to capture spatial heterogeneity in these factors due to fleet composition (age and compliance with control technologies) for PM (Haugen & Bishop, 2018;Park, Vijayan, Mara, & Herner, 2016) and Black Carbon (Preble, Cados, Harley, & Kirchstetter, 2018), or fail to capture the impact of temperature on emissions factors.…”

Investigating the real-world emission characteristics of light-duty gasoline vehicles and their relationship to local socioeconomic conditions in three communities in Los Angeles, California

Cited by 20 publications

References 19 publications

Three decades of on-road mobile source emissions reductions in South Los Angeles

Three decades of on-road mobile source emissions reductions in South Los Angeles

Assessing vehicle fuel efficiency using a dense network of CO<sub>2</sub> observations

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Investigating the real-world emission characteristics of light-duty gasoline vehicles and their relationship to local socioeconomic conditions in three communities in Los Angeles, California

Cited by 20 publications

References 19 publications

Three decades of on-road mobile source emissions reductions in South Los Angeles

Three decades of on-road mobile source emissions reductions in South Los Angeles

Assessing vehicle fuel efficiency using a dense network of CO&lt;sub&gt;2&lt;/sub&gt; observations

Comment on acp-2021-808

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Assessing vehicle fuel efficiency using a dense network of CO<sub>2</sub> observations