A bike lane could be in the works for the ambiguous two-and-a-half-lane section of Alpine Road that runs westbound under Interstate 280. The road is two lanes at a stop sign before the ambiguous section and two lanes after it: one for through traffic into Ladera and the other for traffic headed on to I-280 southbound.
Bikes headed into Ladera must somehow get to the through lane by crossing the freeway-entrance-ramp lane, a dangerous maneuver in traffic.
The half lane between these two lanes is where Los Altos cyclist Lauren Perdriau Ward, 47, died on Nov. 4 after colliding with the left side of a big-rig cab headed for the freeway. Investigators from the California Highway Patrol have not yet determined what happened.
Will that half lane will be re-striped with a bike lane? It depends on whether the California Department of Transportation and the local public works department agree that there is room for one, said Caltrans spokeswoman Gidget Navarro.
How can a cyclist safely negotiate such an interchange? "(It) depends on the skill level of the cyclists, road conditions, traffic volumes (and) road design," Ms. Navarro said.
Asked to comment, former Menlo Park mayor and prominent cyclist Steve Schmidt noted that cyclists of all skill levels use that intersection on Alpine Road. "There's very little guidance on the road in the form of striping to put or direct cyclists into that situation where they're not in conflict with vehicles headed for the freeway," he said.
A boldly striped bike lane sets some ground rules for traffic, Mr. Schmidt said. Several days after the accident, he and representatives of the San Mateo County Public Works Department stood at the Alpine Road/I-280 intersection for about 45 minutes to watch cyclists' behavior.
"A lot of people stay to the right too long and get trapped (in the approach to) the southbound on-ramp," Mr. Schmidt said.
At the other end of the spectrum are "hyper-experienced or hyper-assertive" cyclists, Mr. Schmidt said. These cyclists make the crossing early by approaching the stop sign on the white line separating the two lanes. As they bravely thread the needle in this cramped space, the advantage as they head into the two-and-a-half lane section is that everyone starts from zero, Mr. Schmidt said.
There are mid-road bike lanes where I-280 meets Woodside and Sand Hill roads. The first was done in cooperation with the town of Woodside and the second with Menlo Park and the San Mateo County Bikeways Committee, Ms. Navarro said.
One scenario that Mr. Schmidt found agreeable in making the Alpine Road intersection safer would restrict the left-hand through lane to Ladera traffic and the right lane to freeway traffic, with a dedicated bike lane in between that begins before the stop sign.
Caltrans is aware of the safety issue for "non-motorized users" of the roads. "We are in the process upgrading freeway interchanges to better provide for cyclists and pedestrians," Ms. Navarro said.