Motorists vs Cyclists: comparing the rates of injury to pedestrians in NYC

I recently saw this link on reddit which shows cyclists running red lights, almost colliding with pedestrians. After reading through the comments I realized that many redditors in NYC are themselves cyclists. The discussion in the comments was quite shocking and divisive. The fact that other cyclists were defending this behavior seemed quite annoying since I also read quite often about cyclists injuring pedestrians, and even kill them more often that I can feel comfortable about. My girlfriend is often complaining to me about the citi bikes going the wrong way almost plowing her over on a regular basis. I got to thinking: how often do cyclists seriously injure pedestrians? I took a look for some stats on the subject and found an interesting study on the subject. In 2011 the rate of serious injury of a pedestrian by a cyclist in NYC was 6.06 per 100,000. What I did like to see from this study was that at least the numbers were in decline over the last few years of the study. However, knowing that I have a real chance of being hospitalized by a cyclist got me to not only worry, but wonder: what are the rates for motorists? How do they compare?

Please note: I'm not a statistician. My analysis may be inaccurate so please check for yourself.

Motorists v Cyclists: populations

First I wanted to get a good apples to apples comparison as much as I could. I wanted to find out the total number of motorsits and cyclists and to compare the numbers I found.  A few easy google searches on the subject lead me to nyc.gov sites with DOT stats and reports on motorists, cyclists, and incidents. The best stat I could get for motorists were the DOT registration numbers. In 2013 there were approximately 2 million registered motorists in the five boroughs. For the cyclists I found a document that has counts for cyclist reported from six different cycling hot spots. The average number of cyclists for all months for all six hot spots was about 20 thousand. Given the two numbers I have for both motorists and cyclists and that they are not accounted for the same way, I'm not sure if these numbers are a good basis for comparison however I have no alternative. Assuming that these numbers are comparable, there are 100:1 motorists to each cyclist in NYC.

Motorists v Cyclist: incidents

Likewise for incidents it was very easy to find data on the subject but I was similarly uneasy using what I found as a basis for comparison. For incidents of motor vehicles injuring pedestrians I found a page that summarized the NYPD reports for 2013. Assuming that their reporting is correct I found 12014 pedestrian injuries and 168 deaths for a total of 12182. For cyclists I couldn't find a 2013 set of numbers but I turned back to the 2011 study from the first paragraph to pull the totals. In 2011 there were 501 total injuries by cyclists. Although I can't match apples to apples since the years are different I can only make a broad assumption: there were approximately 24:1 incidents, motorist to cyclist.

Conclusion

Based on the numbers above and taken with some salt you may agree that cyclists are more dangerous to pedestrians than motorists. Based on the data, a cyclist is 4x more likely to injure a pedestrian than a motorist.