South Coast AQMD staff is overseeing the development of a study on high-cube warehouse vehicle and truck trip rates for California Environmental Quality Act (CEQA) air quality analyses; High-cube warehouses attract heavy duty diesel trucks on a daily basis.  Emissions from these trucks produce local and regional air quality impacts that need to be assessed and Mitigated to the maximum extent feasible if they are found significant pursuant to CEQA.  This study provides information regarding the number of vehicles (including trucks) that visit these types of facilities.

UPDATE Draft final results for the Warehouse Truck Trip Study were completed and were lower than South Coast AQMD recommended truck trip rates in the California Emissions Estimator Model (CalEEMod).  Staff recommends truck trip rates from the Institute of Transportation Engineers (ITE) for high cube warehouse projects located in South Coast AQMD.  Consistent with CEQA Guidelines, a CEQA document may use a non-default trip rate if there is substantial evidence in the recording supporting another rate is more appropriate for the air quality analysis.  

WORKING GROUPS

In order to assist in the evaluation of air quality impacts from development of high cube warehouses and distribution centers, South Coast AQMD staff initiated a warehouse truck trip study in 2012.  High-cube warehouses attract heavy duty diesel trucks on a daily basis.  Emissions from these trucks produce local and regional air quality impacts that need to be assessed and mitigated to the maximum extent feasible if they are significant pursuant to CEQA.  The goal of the study was to assess the number of trucks that visit warehouses located in South Coast AQMD.

The final study was produced in partnership with the Institute of Transportation Engineers, NAIOP, and South Coast AQMD is now available.

The study included several components including:
• A business survey
• Two rounds of trip counts at high cube warehouses
• Third party review of the business survey (pages 12 to 24) and trip counts by researchers at UC Riverside

Two working groups were convened to provide input into South Coast AQMD’s truck trip counts and business survey. These included a Stakeholder Working Group (PDF, 126kb) consisting of warehouse developers, environmental groups, and local government transportation and planning staff and a Technical Working Group (PDF, 99kb) consisting of transportation researchers from local universities, two traffic consultants, and a representative from the Southern California Association of Governments (SCAG).  Slides from all of the public meetings held as the study progressed are available below.

Meetings

RESOURCES

• Trip Counts (ZIP, 10.54MB)

• Business Survey Summary (PDF, 2.21MB)

• UCR - Analysis of Business Survey Data (PDF, 189kb)

• UCR - Analysis of High Cube Warehouse (PDF, 840kb)

• Business Survey FAQ

• Scope of Work (PDF, 45kb)

• The previous South Coast AQMD staff recommended trip rate calculation methodology can be found in Appendix E of the CalEEMod guidance (PDF, 1,010kb).

• General guidance for conducting air quality analyses for CEQA can be found in the CEQA Handbook.