This guest post was written by David Gildea, an SVBC member and active bike advocate based in Menlo Park. Thank you for writing this post, David! Got ideas for a guest blog? Email Jessica at

There are new green bike lanes across the overpasses where Sand Hill Road (SHR) crosses 280. The heroes for this are San Mateo County Supervisor Don Horsley and Joe Lo Coco, Deputy Director of Road Services for San Mateo County Department of Public Works. Several previous efforts for improved bikes lanes for this intersection failed when they weren’t able to get funding. In this case Supervisor Horsley allocated $120,000 of funds from the County budget so the project did not depend on grant funds and directed County Public Works to work with us. County Public Works Lo Coco and Public Works did the engineering and design so it would be acceptable to Caltrans and he politicked with Caltrans for 24 months for Caltrans to implement the design.

The zone where SHR crosses 280 has long been known to be extremely hazardous for bicyclists. The westbound (WB) direction overpass had a center bike lane but it was just double white dashes with a sub-standard narrow width. Bicyclists are passed by cars traveling at high speeds on both sides within a few feet of the bicyclists. Cars in the two traffic lanes cross the center bike lane at any point depending on their route. The eastbound (EB) direction overpass was even worse. High-speed drivers mixed with bicyclists in the same traffic lane. People driving from 280 southbound would come around the cloverleaf at near freeway speeds to immediately merge into the same lane as people biking eastbound. Both directions were really scary. Many riders accepted the inconvenience of riding longer distances to avoid the hazard of this intersection. Transportation Information Management Systems (TIMS) data from 2005-2013 showed that there were more car-bike collisions at SHR/280 than the combined intersections of Alpine/280 (before it was improved!) and Woodside/280 intersection.

Several thousand bicyclists ride SHR across the SHR/280 intersection each week. The intersection is part of a nationally known Portola “loop” for people who bike recreationally. People biking from the mid-peninsula funnel through this intersection to ride up to Skyline and the coast. Additionally, people biking to work ride between Portola and Stanford/Menlo Park across this intersection.

The most recent project to improve the bike safety for the SHR/280 intersection started when I met Supervisor Don Horsley at an event in April 2016. I talked to Horsley about improving bike safety and he was sympathetic to the problem. Myself, Bill Kirsch, and Cindy Welton then formed an ad hoc group for bike safety for several dangerous sites in south San Mateo County including the intersection of SHR/280.

We held site visits, meetings, and hundreds of communications with government officials and bike advocates and reviewed several design drafts with Joe Lo Coco. Menlo Park City Council members Ray Mueller and Kirsten Keith supported the effort.

The EB and WB directions for SHR/280 have different challenges. We learned that Caltrans had previously stated that the EB overpass would not accommodate a bike lane unless the overpass was widened. This would require a cantilever construction, which would certainly exceed our funds. We didn’t understand Caltrans’ reasoning, but decided to live with it. We decided to focus on the WB direction in the interest of “doing the doable”. Lo Coco worked with Nikki Nagaya, Assistant Public Works Director of Menlo Park to design a complete green center bike lane for WB direction including the approach (this included sharrows for the crossover from right to center), overpass and continuation. By August 2016, (4 months from start) we had a design for a joint SMC/MP proposal to Caltrans. Then we had a setback.

When the San Mateo County BPAC approved the design in February 2017, there was some debate over whether the funds were being best utilized. Bike advocates collectively agreed that it was important to move forward with the WB design because it had already crossed several design and advocate hurdles, it was within our budget and the existing white markings made it very likely to be accepted by Caltrans as opposed to their previously stated objections concerning the EB overpass. We would use the relationships from the success of the WB design as a platform to tackle the more difficult issues for an EB direction. In June 2017, (15 months from start) Lo Coco submitted the SMC/MP joint proposal to Caltrans for what is called an “encroachment permit”.

We had our second setback in September 2017, when Caltrans unexpectedly scraped all the existing road markings for both EB and WB overpasses. Because San Mateo County is responsible for maintaining the markings and the markings were not considered in need of renewal, this Caltrans action was considered highly abnormal. Apparently the department of Caltrans that scraped the roadway acted without knowledge of the department of Caltrans that was reviewing encroachment permit. The overpasses were now even more dangerous than before. Many people contacted Caltrans, Supervisor Don Horsley, and State Assemblyman Marc Berman to tell them that the overpasses with no markings were extremely dangerous.

Lo Coco treated this setback as an opportunity. He submitted a new design proposal to Caltrans for center green bike lines for the overpasses in both WB and EB directions that had been scrapped. Lo Coco politicked with Caltrans that since the overpasses needed new markings anyway, Caltrans could use SMC funds for an improved green bike lane design. The overpasses remained in this exceedingly dangerous state with no markings until February 2018, when Caltrans restriped the overpasses to match the original markings it had scraped 5 months before. Public Works continued working with Caltrans and Supervisor Horsley’s office on an enhanced design for bike lanes.

Then in June 2018 (26 months after we started) Caltrans installed beautiful green center bike lanes on the overpasses in both EB and WB directions that we have today. We are very happy with the final result. We express gratitude to everyone involved, including Supervisor Don Horsley, Assemblymember Marc Berman, Public Works stafff Joe Lo Coco, Menlo Park City Council, Menlo Park staff Nikki Nagaya, and of course all of the advocates involved.

[Editor’s note: Another stellar advocate, Bruce Hildenbrand, was also involved in pushing this project forward. In one instance, after hearing there wasn’t enough room on the eastbound segment for a bike lane, he used a 35′ tape measure that he found on the side of the road(!) to measure the width of both the WB and EB lanes. He found them to be the same length and communicated this to Caltrans so that no cantilever would be needed.]

Click here for a map of the bike lanes.