The police officer, Scott Dickerson, was pulling out of the condos on Danville Oak Place at 11:30 a.m. As he went to turn right onto Danville Boulevard, he looked both ways and determined the intersection was clear, police said.
"As Officer Dickerson was pulling out to make a right turn, the girl clipped the corner of his patrol car and fell to the ground," said Lt. Mark Williams.
San Ramon police investigated the accident and found the girl to be at fault for biking on the sidewalk instead of the bike lane. She also wasn't wearing a helmet.
"Any driver pulling out of an intersection like that doesn't expect a bicycle to be driving on the sidewalk - given the circumstances that were involved here," Williams said.
"Kids sometimes just don't know," he added. "They don't go home and read the vehicle code."
Regardless of fault, in 95 percent of bike on vehicle collisions someone's going to get injured, he said. But it will happen less if people are educated about the rules of the road.
"We're already in the process - and we were before this incident occurred in Danville - of getting ahead of the game," he continued. "It's a matter of getting our kids to understand bike safety, and what to do and what not to do."
Police have been visiting elementary and middle school classrooms in town, hosting after-school bike safety "rodeos" that include hands-on activities, and sending out safety tips in the school district's newsletter for parents.
Saturday's accident was the third of its kind in the San Ramon Valley in under a month, and in all three cases the injured party was a teen or child.
A 10-year-old San Ramon boy was hit and killed by a bus March 21 while biking home from school. Three days later a teenage girl was hit and seriously injured by a minivan while crossing the street on her bike.
The accidents stirred up worries among residents in the area, said Bob Pack, president of the Troy and Alana Pack Foundation, which sponsors the Street Smarts program.
"It's just kind of raised all the awareness of the continuation of the problem," he said. "When an accident happens, all of a sudden it's on everyone's radar."
Pack and his wife Carmen started the foundation after their children were killed in 2003 by a driver who was under the influence of drugs and alcohol.
Throughout the school year Street Smarts promotes traffic safety at the elementary, middle and high school level for students in the district. It will also participate in community events throughout the summer.
"The whole program is just an ongoing effort for safety in the community," Pack said. "It's a way to raise awareness of traffic safety and allow the kids to kind of get involved."
Bike Safety Tips
* Always wear a helmet and know how to wear it properly
* Use appropriate hand signals to show cars the direction you're headed
* Get off and walk your bike across crosswalks
* Ride on the right side of the street and in bike lanes
* Don't wear baggy clothing that can get caught in the spokes
* Bike in single file, especially on busy streets
* Learn and follow the rules of the road