1. Associated Press, 2007, More Commuters Driving to Work Alone, June 13, 2007.
2. Booz Allen, Hamilton, 1999. California Life-Cycle Benefit/Cost Analysis Model.
3. California Department of Transportation (Caltrans), 2002. 2000–2002 California Statewide Household Travel Survey.
4. California Department of Transportation (Caltrans), District 4, 2002. 2001 District 4 HOV Report.
5. California Department of Transportation (Caltrans), District 4, Office of Highway Operations, 2002. HOV lanes in the Bay Area.