Table 2 Data extraction tool and example of data extracted for a regulatory study of truck emissions [16]

Regulatory policy

airborne pollutants

Year

2011

Author

Dallmann, T.

Title

Effects of Diesel Particle Filter Retrofits and Accelerated Fleet Turnover on Drayage Truck Emissions at the Port of Oakland

Journal

Environmental Science & Technology

Location

Oakland, CA

Study design

Interrupted time series

Study aim

Measure emissions for drayage trucks operating at the Port of Oakland before and after the implementation of diesel particle filter retrofits and truck replacements.

Inclusion criteria

Diesel trucks driving to the Port of Oakland on 7th Street

Exclusion criteria

Trucks entering from other points

Population

3550 trucks passing the field sampling site on four dates in 2009–2010 during sampling periods

Sample size (treatment/control)

3550 trucks, ~70 % estimated to be drayage trucks

Exposure

Air sampling line extended above vertical exhaust stacks of trucks driving below overpass sampling site

Intervention

Diesel particlate filter retrofits and accelerated truck replacement (no breakdown)

Duration of intervention

4 weekday sampling periods ranging from 2.75 to 6.5 h over 7 months (Nov 2009-Jun 2010)

Comparison

Pre- and post-implementation of the California Air Resources Board drayage truck emission control regulation (2010)

Outcomes measures

levels of carbon dioxide, nitrogen dioxide, black carbon, particulate matter

Outcome verification (if self-reported)

air quality samples drawn to gas and particulate phase analyzers

Effect modifiers measured

n/a

Results

CO2: not reported; NO: decrease of 40 %; BC: reduction of 50 %; PM: 5x increase in trucks with no measurable PM, emissions data not reported due to poor instrument response; summary: reductions in BC caused by retrofit/replacement, reductions in NO caused by replacement

Risk of bias

choice of observation dates, concealment of allocation, blinding: not described; incomplete outcome data: emissions for CO2 and PM not reported

Funding source

Bay Area Air Quality Management District, University of California research program in sustainable transportation

Additional information