There's already a fair amount of tension between cyclists, drivers, and pedestrians. Bikers often ignore traffic laws, and many drivers and pedestrians are simply not aware of cyclists. If there is a crash, determining who is at fault can be difficult- which is why cameras are ending up on more and more bikes.
The video is eye-opening, showing a bicyclist in survival mode.
"I try to prepare myself for reacting, so I have my hands on the brakes," says Raf Winterpacht, cyclist. "But a lot of times it happens so quickly, it's hard to react."
Raf Winterpacht is the man behind the lens. He uses a handlebar-mounted camera to show others what he sees: from careless drivers to oblivious pedestrians, to an ambulance crowding his bike lane.
"He's being an idiot," says Winterpacht, of a fellow cyclist recklessly ignoring a red light.
Then, Winterpacht nearly hits a driver leaving his car.
"Instead of waiting for me to go by, he actually just darted across the street," said Winterpacht. "So I actually ended up going between him and the door."
Winterpacht is among a growing number of bikers documenting their rides.
The video of a hit and run accident in California helped identify the driver's license plate.
"When it's a car versus bicycle. . . you have a much greater likelihood that it's going to be a hit and run," said Patrick Salvi, Jr., attorney.
A common cause of cyclist injuries is "dooring," as seen in this YouTube clip viewed nearly 200,000 times.
But cyclist Winfield Cohen says watching a viral video can't compare to experiencing "dooring" first hand.
"I was in a bike lane, got thrown into the street from that bike lane. . . in front of a moving vehicle," said Cohen.
Days in a coma and months of rehab followed.
"I will never get back on a bicycle. . . in the city of Chicago, in city limits with the congestion, even in bike lanes like I was in," said Cohen.
Cohen was injured on the North Side, which along with downtown has the most number of bike crashes. The top three streets: Milwaukee, Halsted, and Clark.
But it's not just densely-populated areas where incidents happen most. Skokie, Elgin, and Berwyn had more crashes in 2011 than more-populous Rockford.
And Evanston, which ranks 24th in Illinois population, was second only to Chicago. Evanston is now adding bike lanes.
"Not only do we have car versus bike, we have a lot of biking on sidewalk incidents, and you're not allowed to bike on the sidewalks," said Suzette Robinson, director, Evanston Public Works.
But bike crashes in Illinois are actually down in recent years, despite the number of Chicago-area riders more than doubling since 2000.
With growth, comes familiarity.
"History tells us with modes of transportation, at some point with more and more use, the number of crashes declines," said Prof. Siim Sööt, transportation studies, University of Illinois-Chicago.
With those bike-related crash figures, it's unclear how many of the incidents were caused by the cyclist versus the driver. Chicago recently increased fines for both drivers who door cyclists and for bikers who ignore traffic laws.