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Road Safety

I-280 Interchange with Page Mill Expressway


World’s Worst Interchange. The Interstate 280 Freeway Interchange with Page Mill Road/Expressway, located along the boundary between Palo Alto and Los Altos Hills, California, is arguably the most unsafe interchange in the world for non-vehicular traffic, such as pedestrians, cyclists, people pushing baby buggies and those in wheelchairs.  In 1965, over a year before it opened, the Los Altos Hills Council recognized the design problems and adopted the following:   A RESOLUTION OF THE CITY COUNCIL OF THE TOWN OF LOS ALTOS HILLS REQUESTING PROVISION OF NON-VEHICULAR WAYS THROUGH INTERCHANGE, 1965.06.07. However, their request was ignored by Caltrans and the interchange was built in the defective configuration originally planned. Unfortunately, the Town of Los Altos Hills did not make further attempts to get it fixed, which is the way that town has generally operated over the 53 years that I have been observing them.


Early Attempts at Redesign.  In 1965, I was recruited by Stanford University to create a new computer research laboratory, which I designed and set up at 1600 Arastradero Road in Palo Alto and named it the Stanford Artificial Intelligence Laboratory (SAIL). Happily, it became one of the top PhD factories in the world. SAIL was located west of I-280, about a mile from the subject interchange with Page Mill Expressway, which was then under construction, and I could see that the design of that interchange was going to make it difficult for both pedestrians and cyclists to go between SAIL and the main Stanford campus, about six miles away, so I started verbally raising that issue with Stanford and the cities of Palo Alto and Los Altos Hills. I was ignored, however, making it an extremely hazardous place for non-motorized traffic, especially during rush hours. Pedestrians and equestrians stopped even attempting to get through at those times because it was clear that doing that would lead to their death.

     I then began documenting my concerns and sending requests to various agencies. A large portion of those writings (dozens to maybe hundreds) have been preserved in an archive at under my ID ( LES) but they are all in old documentation formats that would take a lot of work to manually convert into modern formats such as .pdf. However, new software is now being developed that will soon make such conversions easy to do.


Temporary Success. In the mid-1990s I was appointed by the Town of Los Altos Hills to represent them on the Valley Transportation Authority & /Santa Clara County Bicycle Advisory Committee and was then promptly elected Chair. I then used that bully pulpit to round up funding for a partial reconfiguration of routes for westbound non-vehicular traffic and then got Santa Clara County road authorities to build it, which greatly improved safety there.


Ongoing Failure. Just two years after that successful improvement, a Caltrans engineer proposed another reconfiguration to let motor vehicles travel faster but would make the situation for cyclists and others worse than it had ever been and he refused to listen to my arguments pointing that out, so just just two years after the safety improvements, Caltrans management had it rebuilt so as to reclaim the title of being the World’s Worst Interchange.  All that happened after I had retired from Stanford and the computer I was using then had no archiving service, so the many documents involved in that work were preserved only as paper in my 20-drawer filing cabinets, so it would take a few months of reviews to find them all.


More Attempts. I later continued documenting my concerns. Postings that have appeared on this web site in recent years are shown below in chronological order and are now all in PDF format.

A more direct and frugal route for the S1 Trail, with additional benefits, 2010.06.30. A side path was proposed that remains the best solution to the cycling and pedestrian safety problems in the Page Mill/I-280 Interchange.

A safe route through the Page Mill/280 interchange for non-motorized traffic, 2012.04.23

A Safe Route Through the I-280 Page Mill Interchange for Pedestrians and Cyclists, 2015.11.18, with links to translations into Polish and Czech. Shows a simplified version of the proposed multi-use path along the north side of the Page Mill/I-280 Interchange.

Yielding More And Stopping Less Can Save Time And Fuel, 2016.01.16. A draft resolution submitted to the Traffic Safety Committee of Los Altos Hills proposed a radically different traffic safety policy that would reduce the number of stop signs and encourage yielding and includes specific recommendations for the I-280/Page Mill interchange. However, that proposal was blocked from being considered by the Town Council by the illegal action of Council Member Roger Spreen.

50-year-old highway design blunder takes another victim, a 52-year-old man, 2019.02.14, A review of misconduct regarding the design of this interchange, making it unsafe for pedestrians and cyclists since the I-280 Freeway was completed in 1966.


Will this important matter get fixed before more people are injured or killed? Time will tell.