2011 City of San Francisco Mode Share Survey Summary Report
The survey was conducted as a telephone study among 520 San Francisco residents aged 18 and older during June 2011. Interviewing was conducted in English, Spanish, and Cantonese. Surveying was conducted via random digit dial (RDD) and cell phone sample.
Sampling was designed to include proportional representation by age ranges and geographic zones. Home zip codes were divided among five geographic zones in San Francisco. The five geographic zones were set up to ensure that the survey included opinions from residents of all regions of San Francisco. This zone classification also enriches the data analysis by allowing for comparison between zones.
The data from completed surveys was weighted by age and zone to provide a representative sample of San Francisco residents, based on US Census data for San Francisco.