Alpine Road at I-280 bike lanes

San Mateo County is working to redesign highway interchange where a cyclist fatality took place last November.

Alpine Road provides access from Interstate 280 to Stanford University to the north and residences and parks to the south. Alpine is also a popular road riding route for cyclists riding into Portola Valley from the Bay. Lauren Ward lost her life on Alpine at I-280 last November after she was run over by a semi truck in the highway on-ramp.

San Mateo County have created a set of proposals for bike lanes where Alpine Road crosses I-280 and seek community input. Currently, shoulder striping from the north peters out about a 100 feet before the northbound freeway ramp. From the south, we have the standard Caltrans shoulder striping for freeway designs. Right now, cyclists must pick their way along fast merging traffic. When Paul Andrews of Bike Intelligencer watched cyclists at the intersection, he says he saw numerous ways for cyclists to get past the traffic.

Observing it for more than half an hour, we saw cyclists adopting at least three different strategies for negotiating traffic. One was to ride between the two lanes of traffic to avoid cars angling to the freeway on-ramp. Another was to ride on the far right, next to the curb, and merge left while avoiding cars bound for the ramp. A third was to get up and ride or walk a sidewalk, then cross the on-ramp itself to re-enter Alpine Road.

The County proposes replacing that with bike lanes and dashed stripes across merge zones, with one design (shown below) that proposes a red colored bike lane for the southbound side of Alpine Road.

Alpine Road at I-280 bike lanes

Silicon Valley Bicycle Coalition seeks your input on the proposed designs that can be forwarded to San Mateo County.

A fatality in San Diego along a merge zone for Friars Road at I-15 brought up a similar discussion on ways to improve California’s highway design guides to make it clear that motorists must merge safely across bike lanes.

One Comment

  1. I don’t understand why it is so important to provide the slip lane so that motorists turning from Alpine onto 280 do not have to come to a stop at the stop sign, and then turn right. The design (which is very common around california freeways) forces faster moving traffic to travel to the right of traffic which must come to a stop at the stop sign. Even if you ignore the problems for bicycles, you are sacrificing safety in order to speed traffic onto the freeway by a couple of seconds.

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