DANVILLE -- -- Bicyclists by the thousands were on the roads Wednesday across the U.S. and overseas for a ride like none other.

The "Ride of Silence" honored cyclists who have been killed or injured on public streets and promote the safe co-existence of cars and bikes.

From Danville to San Rafael, Bay Area riders took part in the moving memorial.

Single file, and silent. Those were the rules of the road for the dozens of cyclists streaming through Danville toward Dublin.

They traced the same route that 44-year-old triathlete and father of two, John Greaves of Walnut Creek, took last June.

A driver hit him from behind on a two lane stretch and dragged and pinned him--then plowed into another car.

Daneil Greaves said, "To me, I'm gonna say that was an intentional act, even if she was inattentive, because she was driving inattentively."

The driver who struck Greaves faces felony manslaughter charges, but the cyclists riding in his memory said it didn't have to happen, if everyone shared the road.

David Leath was Greaves' riding partner and said, "We can all get along out there. I'm a rider and a driver, and I see it too. There's room for improvement on both sides."

"People just don't like us as users, it's like it's my road, I own the road, what are you doing?" said the victim's brother-in-law, Robert Fuller.

In Marin County, the heartbroken parents of 22-year-old Sylvia Bingham also took part in the Ride of Silence, with a white "ghost bike" to symbolize its missing rider.

Sylvia was fresh out of Yale and commuting to her new job in downtown Cleveland last September when a commercial truck turned into her path.

Her father, Steven Bingham said, "She didn't have a chance, she was crushed and died almost instantly."

"He didn't stop, he said he never knew what happened. We'll find out when he goes on trial," said Stephen Hesson of the Marin County Bicycle Coalition.

These rides, small and large, started in Dallas seven years ago, after a prominent cyclist was hit and killed by a passing bus.

In the year's since, cyclists said, driver's have become more aware of their rights, but also more distracted while driving.

Either way, it's a dangerous mix when both groups aren't watching out for each other.

Daneil Greaves misses her husband deeply, and wonders when their seven year old son will be willing to ride his bike again.

"We do need to share the road, we need to take a pensive moment before we get behind the wheel. And it does just take a second," said Greaves.

The annual ride of silence is completely grassroots: No sponsors, fees, or sign-ups.

In the Bay Area, Santa Rosa and San Francisco also hosted rides.