The U.S. National Highway Traffic Safety Administration released their 2012 traffic fatalities numbers yesterday, and the wonkier blogs make note that cyclist and pedestrians fatalities increased faster than those of car occupants. Between 2011 and 2012, we had a 3.3% increase in traffic fatalities in the United States, while cyclist and pedestrian fatalities increased by 6.5% and 6.4% respectively.
How does the Golden State fare in this accounting? 124 people were killed in crashes while biking in California, representing 4% of the 2,857 people killed on California roads and highways. This is a 7% increase over the 116 people who lost their lives while biking in 2011.
In my home county, zero cyclists lost their lives out of the ten traffic fatalities in Santa Cruz County. We had a single loss of life in 2011.
Let’s look at the San Francisco Bay Area, where many Cyclelicious readers hail from:
- Alameda: 3 cyclists killed out of 61 total traffic fatalities in 2012. 5 cyclists killed in 2011.
- Contra Costa: 7 out of 60. 2 cyclists killed in 2011.
- Marin: 1 cyclist out of 9 total fatalities. 0 in 2011.
- Napa: 2 cyclists out 7 fatalities. 0 in 2011.
- San Francisco: 1 cyclist out of 29 total traffic fatalities. This matches the single fatalities in 2011.
- San Mateo: 3 cyclists, 38 traffic fatalties in 2012. 3 cyclists also lost their lives in 2011.
- Santa Clara: 3 cyclists killed in 2012 with 84 total traffic fatalities. No change from 2011.
- Solano: 0 fatalities out of 19 total. A single cyclist was killed in 2011.
- Sonoma: 2012 was a bad year with 5 cyclists killed out of the 37 traffic fatalities. In the previous year, a single cyclist was killed. A mode for Sonoma County is zero cyclists killed.
We like to talk about numbers like this in terms of Vehicle Miles Traveled. We have pretty good automotive data and understand that, nationwide, the increase in total fatalities tracks with the increase in increased mileage people put on their cars in 2012 compared against 2011. When people drive more, you’ll get more collisions on the road.
We only have road use data for cyclists in very limited form in the USA, unfortunately, so we have little idea if a 6.5% increase happened because there are more cyclists on the road, and if there are more, how many more? If we have 50% more cycling miles in the USA and a 6.5% in fatalities, this means cycling has become safer year over year. If cycling has increased only 5% year on year, however, then we know cycling has become comparatively more dangerous.
I allude to this statistical problem in a comment over at Biking In LA.
Look at the numbers for LA County, which shows a 30% *decrease* from 2011 to 2012, in spite of an estimated 13% *increase* in estimated the number of bike commuters year over year.
Does this show there are safety in numbers? We really don’t know. It only shows that cyclists are so few that any small difference in absolute numbers results in large percentage changes.
(“Estimated bike commuters” is my proxy for the number of cyclists, since it’s the only number we have that I’m aware of for LA County. The US Census estimates 0.9% of commuters (or 38986 rode bikes to work in 2012. In 2011, the estimate is 0.8% / 34622 people. Both of those figures are ±0.1%. I use the absolute number of people on the road vs the percentage of population, since we’re looking at absolute changes in fatalities.)
I leave it as an exercise for the reader to determine where those extra 44 fatalities nationwide came from.
Santa Cruz County (where we’ve had zero to three cycling fatalities per year since 2008) does an annual bike and pedestrian count where we’ve seen a modest uptick in bicycle use over the past few years. A high percentage of Santa Cruz County residents use bikes to get around and for recreation.
Cyclist fatalities increased more than car occupant fatalties
Cyclist fatalities increased faster than car occupant fatalities year over year, and some observers suspect this is at least partly due to improved safety for car occupants with air bags, crumple zones, anti lock brake systems, traction control, and other innovations to improve survivability in car collisions. People feel safer, but risk homeostasis encourages us to keep the risk level constant so we mitigate this “safer” car by driving more dangerously. The result: car occupants are indeed safer, but at the expense of those of us outside of the motor vehicle.
With thanks to the mystery tweeter behind People Power Santa Cruz, who notes Data for Santa Cruz County shows drivers more likely to die than bikers & peds and pointed me to this county by county breakdown of 2012 traffic California fatalities. I also look forward to further analysis from data wonk Dan S.