This is a conflict on the use of urban space and on the means of urban transport, a conflict because of claims in favor of pedestrians and cyclists. Since the early 1990s, Critical Mass rides take place in hundreds of cities globally, generally on the last Friday evening of every month. They are meant to counter the vulnerability single riders normally experience by gathering a group of cyclists that is large enough to temporarily take over roads.
On 25 of February of 2011, one automobile driver ran over 17 cyclists, during the Critical Mass of Porto Alegre. Up to 130 cyclists were in the Critical Mass event , there were no deaths, but several people were injured. This celebration/protest is done regularly in the city every last Friday evening, part of the idea of is to experience how is to be the majority of traffic, how it feels to be safe . The driver, Ricardo Neis, lost his patience and accelerate rapidly against the cyclists . According to his testimony, he acted in self-defense being intimidated by the participants in the march and his intention was to protect his 15-year-old son, who was traveling with him in the vehicle . According to witnesses present at the event, Neis was acting violently behind the bicycles and hit the rear wheels of two different cyclists, and the contact from the cyclists on his car was meant as a sign asking him to slow the vehicle down . The driver never stopped, they were waiting for the police to arrest the driver, but nothing happened. Someone shouted out that they should meet. So they organize a meeting for the following Sunday in “Cidade da Bicicleta”. More than 200 people showed up, even people who didn’t participate in the critical mass before, but wanted to help. After many hours of discussion they reached the decision that they would march the following Tuesday asking for more humane cities and for the end of impunity for traffic crimes . On the march of Tuesday, there were posters saying “it was not an accident” and stickers going around, there was also a group of Samba singing thematic lyrics. Someone also built a cage with PVC pipes around his bike. They went to the site were the critical mass was hit, they lay down screaming and cried. “It was a defining event because it forced people to confront the fact that our traffic is really violent” .About 4,000 people were marching in the streets. Finally they did a die-in and stayed in front of the City hall. The major didn’t show up, but the secretary of local governance came out. They proposed regular meetings between cyclists, City Hall and Porto Alegre`s department of transportation. The meetings were done afterwards, but they didn’t work because almost all demands were ignored, and the ones which were accepted first, afterwards they were rejected. As Marcelo Kalil wrote "our strength is in the streets", “we do politics in the street” . Some of the slogans also stated that “Ricardo Neis is just a reflection of the violent traffic”, and also “that this don’t destroy us, but makes us stronger”. That was exactly what happened. In the next critical mass, they were more than 500 bicyclists. People in the streets and houses showed their support to the group .