Over 100,000 Californians were expected to participate in Bike to Work week, which is May 15th through 19th. On Thursday, May 18th, which was Bike to Work Day (BTWD), people in some place joined together to ride to work. In cities such as San Francisco and Berkeley, local organizations sponsored energizer stations with refreshments and other bicycle-related goodies. In Modesto, riders had the option of riding with bicycle police officers (?) or riding by themselves. 511.org's Bike to Work Day

Some local events:
On Saturday, May 13th, Bike Day at the Berkeley Farmer's Market will include bicycle outreach, education and safety from 10:30am to 2:30pm.
On May 18th, BTWD in Berkeley will include energizer stations. Read more In Oakland, there will be a Bike to Work Day celebration at City Hall from 7:00am to 9:00am. More Oakland energizer stations BTWD in San Francisco included a 6pm Bike Away From Work party at 111 Minna Gallery. Energizer stations in SF Contra Costa County energizer stations The Sacramento Bike Commute Month celebration included a BikeFest on the west steps of the Capitol from 11am to 1pm.

A California Bicycling Information website recommends that people prepare themselves in advance for a bike commute. Steps to take include: planning the safest (and least traffic) route to work; informing supervisors about bike commute plans and asking where the bicycle can be parked during working hours; making sure that the bicycle is in proper working order; dressing to cycle (this includes planning to wear everything from a helmet to comfortable bicycling clothes); and inflating tires before starting the commute. Bicycle safety activists also warn that riders should stay out of the range of doors of cars that are parked along the bike route (approximately 5 feet) to avoid getting "doored." California's bike-related laws

California Bicycle Coalition | Placer County | Bike to Work Day Sacramento | Sacramento Region Bike Commute Month | Solano Napa | Sonoma County | Marin County | Oakland Bike to Work Day | Bike to Work Day in the Silicon Valley | Bike to Work Week in Santa Cruz | Bike to Work for the Monterey Bay Area | Fresno County Bicycle Coalition | Bicycling in Modesto | League of American Bicyclists CA Bike Month list | East Bay Bicycle Coalition | California Bike Commute | National Center for Bicycling and Walking