As he tried to follow the Bay Trail from University Avenue to Willow Road, the 43-year-old cyclist ended up in the Facebook campus parking lot in Menlo Park. A 27-year-old employee turning left in her Honda Accord to enter the lot didn't see him until it was too late, police said, and struck the rear of the bike.
"Took me right out," Mr. Lowenthal said. "Usually bikes hit the car, but she actually didn't see me."
A week later, he's healing from injuries sustained in the accident, but worried that the situation is ripe for a more serious collision because "there's very little signage about the fact that there are bikes there." Mr. Lowenthal also suggested that a lack of space forces bikes and cars into close quarters without room to maneuver safely.
Andrew Boone of the Silicon Valley Bike Coalition agreed that that portion of the trail confuses people. "The Bay Trail is discontinuous for a 200-foot section near the east entrance to the Facebook Campus. Here, pedestrians and bicyclists travelling on the trail must cross a parking lot that contains no pavement markings to indicate where they should go, as the bicyclist who was struck by a car there has described," he said in an email.
Using highly visible green paint to designate 200 feet of bike lane would be a simple solution, according to Mr. Boone. "This would also prevent pedestrians and bicyclists who might not see the signs for the trail from erroneously entering the Facebook Campus."
A lack of appropriate pavement markings is a longstanding factor in many traffic accidents, he said. Bike lanes and shared lanes should be clearly marked so that bicyclists as well as motorists know where it's safe to be.
"Instead, we expect bicyclists to 'use their judgement' wherever there are no markings instructing them where to ride. The result is unpredictable behavior by bicyclists, which leads to many traffic accidents."
A Facebook spokesperson said the company will take a look at that segment of the trail. "If it makes sense, we will review ways to make the Bay Trail near our campus more clearly marked so that local cyclists will ride with greater confidence and less confusion."