Safe Lanes – A platform for improving San Francisco’s bicycle lane network.

One month ago I created Safe Lanes, a platform to monitor and analyze the public reporting of blocked bicycle lanes on the streets of San Francisco. Here’s why I created it and what I’ve learned so far.

On any given day in San Francisco approximately 40–50 reports of vehicles blocking bicycle lanes are reported to 311, the city’s public health service. This is alarming because every time a motorist drives into or obstructs a bicycle lane, they force cyclists to merge into fast moving vehicle traffic that can seriously injure or kill them.

A realtime map of every blocked bicycle lane in San Francisco

On March 8th, Tess Rothstein was forced out of the bicycle lane by an inattentive parked motorist who suddenly threw open their door knocking her into the vehicle lane where she was crushed to death by a box truck. Had the motorist known to look over their shoulder before opening the door and had Tess been riding her bike in an unobstructed, parking protected bicycle lane, there is no doubt that she would still be here with us today.

Every year approximately 30 people are killed and over 200 people are seriously injured while traveling on the streets of San Francisco. In just the past five years alone 17 people have been killed while riding their bicycle on San Francisco streets. Each year we honor their lives during our annual ride of silence and each year we as a community ask ourselves, how can we stop this from happening?

Friends and family members who were killed by a motor vehicle while riding their bike in San Francisco

As someone who has not owned a car for 11 years of living in San Francisco and commutes by bicycle daily I am terrified that it is just a matter of time until I, my wife or someone I know is the next name to be added to this list. If it happened to Tess Rothstein, if it happened to Harold Swaggard, if it happened to Gashaw Clark, Charles Vinson, Renata Gonzalez or any of the other beautiful souls on this list, it can happen to me and it can happen to you.


Making San Francisco’s streets safer and achieving Vision Zero is not some pie in the sky, unattainable goal nor is it rocket science, nor should it require thousands of years of planning discussions and environmental impact studies.

It takes the following three things and political will to make our streets safer:

  • Public awareness of the problem and a clear call to action.
  • Efficient enforcement of the laws in place designed to protect our citizens and existing infrastructure.
  • Transit infrastructure upgrades informed by data that reflects historical incident and behavioral patterns.

“The first step in solving any problem is recognizing that there is one.” — Aaron Sorkin

Vision Zero, The SFMTA’s sub-committee tasked with eliminating all traffic related fatalities on San Francisco streets by 2024, recently launched a campaign to bring attention to locations where pedestrians and cyclists have been killed on city streets.

Tess Rothstein’s ghost bike on Howard St. and Vision Zero’s nearby placard

While a sign calling attention to what has happened at a location is certainly welcome, it leaves the engaged reader asking: “How did this happen and what can I do to prevent this from happening to me?”

A call to action on such signs might be an invitation to attend an upcoming event to learn more about traffic related injuries in San Francisco and connect with a community that can empower you to help prevent them.

The centerpiece of Safe Lanes is a map that displays every blocked bicycle lane report in San Francisco moments after they are received by 311. The map refreshes every 60 seconds allowing you to see your report on the map almost instantly after submitting it. This provides reassurance that your report was received and allows anyone to see it alongside the numerous other reports submitted throughout the city. This is particularly powerful along corridors that chronically experience a high number of reports such as Valencia, Polk, Market, The Embarcadero and Second St.

Search reports and apply filters to view reports along specific corridors or throughout a specific date range

Since Safe Lanes launched in early March the SFMTA has seen a 270% increase in the number of reports submitted compared to the first two months of this year. Lane Breach, another reporting app which also launched in March, has certainly contributed to this uptick in engagement as well.

The SFMTA received a whopping 375 reports of blocked bike lanes during the week ending April 13th 2019

Now that we know that vehicles blocking bicycle lanes in San Francisco is a major problem, what do we do about it? With SFMTA’s limited resources they cannot be expected to dispatch a policy control officer as every report comes in. The solution is to strategically deploy enforcement along corridors that have historically received a high number of reports at specific times of the day.

This chart identifies corridors with a high number of blocked bike lane reports at specific times of the day

As you can see in the above chart, Second St. (purple) experiences more reports than any other corridor between 8–10AM. The Embarcadero (teal) experiences the most reports during the early afternoon hours of 12–4PM. The vast majority of these are reported at Pier 33, the site of the ferry launch to Alcatraz. As the evening rush hour sets in, Valencia St. (burgundy) starts to climb way up from 5–8PM as commuters head home along San Francisco’s second busiest cycling corridor after Market St.

It shouldn’t take much to imagine the impact that dispatching enforcement along these corridors at these times would have.

As May is National Bike Month, I am asking the SFMTA to recognize this analysis and immediately respond to it in the interest of all San Franciscans, especially those who have been severely injured or killed as a direct result of inadequate action.

While a proactive response from the SFMTA along these corridors can and will save lives it will also provide the agency with a valuable opportunity to evaluate various enforcement strategies and optimize resources as traffic patterns and the location of incident reports continue to change.


While enforcement is important, it doesn’t stop there. To truly solve the problem of obstructed bicycle lanes in San Francisco and make our streets safer for everyone we must design and build transit infrastructure that eliminates the need or possibly for motor vehicles to drive into our bicycle lanes in the first place.

A beer truck parked in the protected bicycle lane in front of The Mint karaoke bar on Market St.

Exactly one year ago The SFMTA completed the Upper Market Street Safety Project which included a much celebrated protected bike lane from Octavia St. to Duboce Ave. On my way home from a rally for safer streets at City Hall last month, I came across this beer truck parked over the cement divider in front of The Mint karaoke bar on Market St. When I approached the driver, he exclaimed that “they didn’t make the loading zone wide enough” and so he had nowhere to park that would allow him to safely unload his truck through the side doors. He didn’t want to obstruct the bike lane, he felt that he had to to preserve his own safety.

This is a lesson that the SFMTA planning department urgently needs to heed. The vast majority of motorists don’t intentionally want to obstruct our bicycle lanes, they simply too often find that they don’t have an appropriate loading zone that would allow them to avoid doing so.

At a recent open house for the Fifth Street Improvement Project I asked how blocked bicycle lane reporting data has informed designs for curb management along the corridor. The current designs for the corridor show a variety of large businesses with adjacent loading zones but do not show any of the smaller bars or restaurants that are sure to invite ride share activity on evenings and weekends. When pressed about how blocked bicycle lane data submitted to 311 has informed any of these designs, I was told that it likely hasn’t.

The point is in addition to community outreach and stakeholder interviews, we have to be designing against the data we have that communicates what people have historically done and are very likely to continue to do, otherwise we are literally spinning our wheels. If the SFMTA’s only excuse for ignoring this data is a lack of resources, I know of a few people ready and willing to jump in and lead the way.