San Francisco first Critical Mass as a challenge to pro-automobile urban planning, USA

Car and oil industries helped to shape the city of San Francisco around the private vehicles. Within this context, in the early 1990s a world famous form of cycling protests appeared: The “Critical Mass”.


This is a conflict on the use of urban space and on the means of urban transport. By 1930 in San Francisco, car based transportation benefitted from giant public expenditures, even when they were being used by a relatively small minority of population. The investment on car infrastructure was far greater than the investment made in public transportation. Also, the electric street cars were left aside and the streets where they operated taken by the private vehicles [4]. One graduate student Miller McClintock became a prominent traffic researcher, in 1925 in his thesis: “street traffic control” he wrote that “widening streets would merely attract more vehicles to them”, “the automobile is a waste of space compared to the streetcar” and describe the automobile as “the greatest public destroyer of human life” [4]. But two years later his perspective radically changed after being hired by Studebaker’s Vice President (automobile manufacturer) to head up the new “Albert Russel Erskine Bureau for Street Traffic Research”. After these two years he wrote an article called “Curing the Ills of San Francisco Traffic”: “… it is recognized that an ultimate requirement for the solution of street and highway congestion is to be found in the creation of more ample street area” [4]. He became one of the most recognized authorities on traffic planning, now with a pro-automobile vision. By that time, Ford was already a growing business with an office in one of the most famous squares. A fair made in New York city in 1934 “the world of tomorrow” built by General Motors, exhibited a vision of “San Francisco in 1999”, to redesign San Francisco as a Corbusian city, with elevated roadways and highways. In the spring of 1937, Shell oil company combined McClintock`s traffic expertise with the stage designer Norman Bed Geddes to build a scale model of “the automobile city of tomorrow”.  The City of Tomorrow, a model created in 1937 to promote Shell Oil Company’s new “motor-digestible”

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Basic Data
NameSan Francisco first Critical Mass as a challenge to pro-automobile urban planning, USA
CountryUnited States of America
SiteSan Francisco
Accuracy of LocationHIGH local level
Source of Conflict
Type of Conflict (1st level)Infrastructure and Built Environment
Type of Conflict (2nd level)Urban development conflicts
Specific CommoditiesDisproportionate use of urban space by cars. The commodity casing the conflict is cars, and urban planning at the service of the cars.
Ecosystem Services
Project Details and Actors
Project DetailsBy 1996, the Critical Mass of San Francisco reached 2,000 people. And in July 1997 reached 5,000 people off course; it was not anymore a bicycle ride of 60 people. It has been accused of creating traffic congestion. The answer for these critics is now a famous phrase: “Critical Mass isn’t blocking traffic, but we are traffic”. A criticism of the perception of the cars as owners of the public road.

One of the obvious conflicts is with the car drivers, since they have to wait until the last rider to pass. But it is key to think of the car drivers not as enemies, but as possible future riders. As Chris Carlsson states “the people inside the cars cannot be categorized as bad” and having fun is one of the most subversive postures cyclists can take, instead of the anger…doing the unexpected [13].

Another conflict they face is the relationship with the police, who want to enforce the rules. In April 1, 1994 police “claim the sponsorship”. So the Critical Mass agreed that the police would stop the traffic for them, they will be the “corks”. They wanted to be the ones who stopped the traffic, in order for the Critical Mass to pass. But the experiment was a failure; they didn’t stop the traffic, and even arrested some cyclists trying to do so. Therefore, 75 people were left behind, creating dangerous situations [14]. The police intervention is no longer wanted, and it is avoided in many critical masses around the world.

Another type of conflict is that there are attempt to officialize it. Meaning that they will need a permit to do it, and the police would have the control of the routes, and the power to create “mini masses”. The overall aim is to reduce congestion, the car congestion.
Type of PopulationUrban
Start Date25/09/1992
Company Names or State EnterprisesShell Oil Company from United States of America
Studebaker from United States of America - McClintock financing
General Motors (GM) from United States of America
Relevant government actorso San Francisco Police Department

o Department of Parking and Traffic

o SF Bicycle Advisory Committee
Environmental justice organisations and other supporterso








o SF Bike Coalition:
The Conflict and the Mobilization
Intensity of Conflict (at highest level)HIGH (widespread, mass mobilization, violence, arrests, etc...)
When did the mobilization beginIn REACTION to the implementation (during construction or operation)
Groups MobilizingInformal workers
Local ejos
Social movements
Recreational users
Forms of MobilizationArtistic and creative actions (eg guerilla theatre, murals)
Creation of alternative reports/knowledge
Development of a network/collective action
Land occupation
Media based activism/alternative media
Street protest/marches
Occupation of buildings/public spaces
A good example of non-violent direct action
Environmental ImpactsPotential: Other Environmental impacts, Air pollution, Noise pollution
OtherUrban land use at the service of motor vehicles
Health ImpactsVisible: Accidents
Socio-economic ImpactsVisible: Loss of livelihood
Potential: Loss of landscape/sense of place
Project StatusProposed (exploration phase)
Pathways for conflict outcome / responseStrengthening of participation
Development of AlternativesXerography

Critical Mass Alliances with other cities

The critical Mass has been adapted for different purposes: "Clitoral Mass" a feminist ride. ""World Naked Bike ride". And each city has adapted the concept of critical mass to its needs.
Do you consider this as a success?Yes
Why? Explain briefly.This movement has trascended generations and countries keeping the name of "critical mass", to enforce cyclists rights. Its open re-interpretation and non hierarchical structure makes it open to all.

The riding itself is a reivindication of the bicycle, an anarchic type of using the streets that have been non designed by bicycles. And the main role, might be in posing questions on urban planning and the oil industry by the ones who are riding, and also the pedestrians, while drivers of motor vehicles are watching (and welcome to join).

Nevertheless, it has received critics about non being succesful in involving the working class in bicycles, that are being riding in the streets for decades.
Sources and Materials

[10] How to make a critical mass
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[9] Furness, Z. (2010). One less car.

[15] Cabezas, D. (2016). La revolución silenciosa. Barcelona: UOC.

[2] Furness, Z. (2007). Critical Mass, Urban Space and Vélomobility. Mobilities, 2(2), 299–319
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[4] Automobiles Take Over San Francisco Streets
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[5] Highway revolts in the United States
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[7] Critical Mass definition. Wikipedia
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[11] Critical Mass essays, flyers, images from San Francisco, 1992-1998. (and a few from the 21st Century), by Chris Carlsson, Jim Swanson, Hugh D'Andrade and friends
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[1] How to make a critical mass. Lessons and Ideas from the San Francisco Experience
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Media Links

[3] San Francisco Critical Mass FAQ
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[6]We are traffic documentary
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[8] Ted White's documentary : Return Of The Scorcher
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20 years of San Francisco critical mass
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Other Documents

Critical Mass goes city Hall uninvited
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Critical Mass. Dont wait for the automobiles to act "FOLLOW ALL THE RULES. Bikes will rule the roads. Various groups of bikes can turn and ride on ANY STREET THEY CHOOSE in ANY SIZE GROUP. As we all meander around downtown, slowly heading westward, we’ll cross each other’s paths, and can switch groups and join and separate as the whim strikes us—JUST AS IF WE WERE JOYRIDING AROUND"
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The Critical Mass of San Francisco
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Critical Mass San Francisco Illustration by Jim Swanson:
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Critical Mass One year old Illustration by Jim Swanson.
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Critical Mass: Ride daily, celebrate monthly Ilustration by Beth Verdekal.
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Meta Information
ContributorSandra La Rota, Universidad Autónoma de Barcelona.
Last update06/06/2017