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Got these numbers from various transportation authorities.

How many people bike to work?  This appears to vary from report to report.  In the year 2000, it was reported that 2% of all commuters to work used a bike in San Francisco per the Citywide Bicycle Count report, a number that grew by 15% by 2007.  In 2006 it was calculated for the American Community Survey on Bicycle Commuting Trends that 4.4% biked to work in Portland, based on a sensor recording 16,700 crossings of a bridge in one day.  In 2005, .5% of commutes in New York City were deemed by bike.  In 2000 and in 1990 the United States Census estimated under .5% of commutes to work were by bike (.41% in 1990, and .38% in 2000).  9 million daily trips are estimated by the Nationwide Personal Transportation Survey in 1995.  The American Community Survey of 2007 estimated nationwide about .5% of trips to work to be on a bike.  Only 5% of all bikers commute to work by bike as their primary means of transportation (26% for recreation, 24% for exercise, 14% to go home (?), 14% for personal errands, 10% to visit a friend or relative).  11 million bikes were sold in 2001 for adults.

Injuries and fatalities: Using 2007 statistics of the National Highway Traffic Safety Administration, there were 43,000 non-fatal biker injuries (no further statistics on the breakdown of seriousness of these) and 698 were fatal nationwide.  Another report states 677 died in 2011, the most recent number that exists.  There has been a noticeable drop from under 1,000 in the late 1980s, about a 30% drop.  When one examines the increase in government spending on bike safety nationwide, the reduction in accidents parallels these (but of course correlation is not causation) – only $4.9 million was spent in 1988 and $541 million in 2008, a stunning magnitude of 135 times over that 20 year period. However, it estimated that only 10% of non-fatal injuries are reported to the police, which would mean 430,000 nationwide would be closer to the real number.  All fatal injuries are reported to the police and so the 698 and 677 are as accurate as is possible.  Biking fatalities represent 2% of all traffic fatalities (but that does not mean it is a low number until we account for the proportions of trips rendered by each type – superficially, we could say it is high if 2% of fatalities are on bikes, but only .5% use their bikes as frequently as car drivers, for example for commuting).

The National Highway Traffic Safety Administration reports that 87% of those killed were male (an interesting finding, unless males over-represent biking). 

Very significantly, helmet use diminishes head injuries (the greatest cause of death) by 85% (as only 15% of those who died were wearing helmets).  This is a cause that is within the complete control of the biker.  36% of fatal bike accidents occurred at intersections.  This is also a variable likely within some control of the biker taking extra caution at intersections.

64% of fatal accidents are on major roads, 31% on minor roads, and the remaining 6% on highways! (probably not because it is safer on highways but because few people attempt to bike at the edge of highways and many of them do not survive, but I am speculating).  It is not clear what that would mean in Chicago but I would guess major roads are Irving Park Road, Ashland and Western, however it is hard to consider Damen, Wells and Dearborn as minor either.  One would need to plot the locations of Chicago fatalities to get a better picture of the most dangerous roads – I am sure they exist and I am sure we are likely to live longer avoiding them totally (most of them likely do not have bike lanes either).

There are roughly 30,000 car accidents a year that kill 22,000 people inside the car (the remainders are people outside the car who are killed by cars when the driver did not die).  About 15 people die per 100,000 drivers. There are 125,000,000 cars (I am ruling out trucks as likely to kill bikers, at least in the city) and one study hypothesized 65% are in use on average twice a day on a given day, thus 162,000,000 trips.  That would mean .185% of all car trips have fatal accidents. 677 bikers have died out of 9,000,000 bike trips per day or about 0.007% of all bike trips have fatal accidents.  I am sure my numbers are all inaccurate since they are based on estimates, but if they were true, biking is half safer than riding a car.  Both forms of transportation come with risks.  I suppose bike risks are different than car risks as cities design bikes to share road spaces with cars - I suppose if city designs led bikes to share part of, or a segregated part of, sidewalk spaces with pedestrians there were be as many fatalities as there are now in the parks (likely approaching zero).  So city design has a lot to do with this problem and not just bad drivers.  Cars are big boxes of metal that protect their drivers a lot better from bikes (but not from other cars) than our bikes can protect us from them.  My guess is the protected lanes like we see on Dearborn will greatly enhance safety, and they are more a type of extension of sidewalks than lines drawn on real car roads.

What we would need to do with existing city design of bikes on streets to reduce our chances of dying on our bikes based only on these numbers is a) wear our helmets (that won’t prevent a horrible incapacitating accident, only reduce our chances of a deadly one); b) do not cross that street unless you are completely sure no cars are crossing the other way or planning to zoom around a corner from behind you or making a left turn into you from the opposite direction; c) do not bike on a major road (let’s define this for now as a big Chicago road with no bike lanes); and d) (not included in my statistics but my guess) do not drive within a car door’s width.  last minute e) driving in numbers should reduce fatalities too - have our Critical Masses killed any of us yet?

End of me playing statistician.

 

 

 

 

 

 

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