California Air Resources Board

Principal Investigator/Author: Paul Ong

Contractor: University of California, Los Angeles

Contract Number: 15RD010

Project Status: Completed

Relevant CARB Programs: Climate Change

Topic Areas: Greenhouse Gas Emissions, Sustainable Communities

Research Summary:

To ensure that that SB 375-related greenhouse gas (GHG) emission reductions are achieved, it is critical to assess if real-world changes are occurring in the urban spatial structure to make it easier for Californians to stay mobile and get where they need to go without driving as much or as far. SB 375's intent was "move the needle" in communities and regions throughout the state by facilitating better land-use and transportation planning via the creation of regional sustainable communities strategies (SCSs). This project establishes a foundation for a future, statewide system for assessing and monitoring changes in the urban spatial structure that typically result in vehicle miles traveled reductions. It achieves this by identifying, evaluating and selecting data, indicators, and indices that can be used to monitor changes relevant to SB 375.

To fully evaluate potential indicators and the data used to construct them, the researchers prototyped a monitoring system for Los Angeles County. This prototype evaluates changes in new housing units, jobs, and retailing on one-year and four-year timescales against 2010 baseline indicators - housing unit density, access to jobs, access to retail, and access to transit (bus). The results from the prototype monitoring system are mixed: some developments are and others are not consistent with SB 375 goals. While the results suggest that new housing units are located in areas with greater transit access, it also shows that housing, jobs, and retailing are becoming more geographically dispersed.

This report also examines metropolitan planning organizations' (MPOs) current practices that may be relevant to monitoring short-term changes in land use. Overall, MPOs conduct limited assessment of recent changes to land-use activities and the built environment. Where such monitoring occurs, the processes are partial and inconsistent across agencies. Consequently, it is not feasible to construct a statewide monitoring system by assembling information from MPOs. Instead, a unified statewide data system should be built on a common database, utilizing the same methodology, and a uniform set of baseline indicators and measurements of short-term changes. This report also includes recommendations for how to refine the Los Angeles prototype monitoring system for upscaling to state-level analysis.

Final Report: Please email research@arb.ca.gov to request the final report generated by this research contract.

Related Links:

• Phase 2 of this study (Caltrans-funded)