Senator Wiener's transit-oriented development proposal would establish new zoning requirements near California rail stations and rapid bus lines, requiring local jurisdictions to allow higher-density housing development in these transit-rich areas. The measure creates a framework for "upzoning" - increasing allowed housing density and building heights - with requirements scaled according to transit station proximity and the capacity of nearby transit infrastructure.

The bill directs local governments to incorporate these upzoning provisions into their housing elements, though jurisdictions that already maintain higher density or more permissive standards would be exempt. Transit agencies would gain authority to set residential and commercial zoning standards on properties they own or operate, provided these standards exceed local requirements. Properties meeting the new zoning criteria could access streamlined development approval processes if they satisfy existing labor and environmental standards.

To support implementation, the measure requires consultation with local governments, transit operators, housing advocates, and environmental groups in developing specific upzoning criteria. The bill also aims to expand transit agencies' revenue sources beyond current public subsidies and fare collection, though detailed funding mechanisms would be addressed in subsequent legislation. Local jurisdictions must adopt compliant policies within timeframes to be determined, with outcomes monitored for alignment with state housing and transportation objectives.

The proposal builds upon existing transit-oriented development regulations, including current San Francisco Bay Area Rapid Transit District requirements for minimum height, density, parking, and floor area ratios near stations. According to the bill's findings, California faces housing shortages particularly acute in transit-accessible areas, while transit systems receive proportionally less state funding than comparable systems in other states.