I did my critique this week on a website called “CrashStat.org”, which measures traffic accident data using Google Fusion Tables. The site has a key on the right hand side indicating both the number of accidents that have occurred in each intersection using round blue and red bubbles (blue for pedestrian, red for bike) which can vary in size as well as the number of bike or pedestrian fatalities. The fatalities are indicated with gruesome spikey, black ninja-star-looking things with a little white stick figure or bicycle within them.
You can click on each marker and view how many accidents have happened at that location on a year-by-year basis. The site is incredibly effective at communicating which areas are the worst for pedestrians or cyclists. In addition, CrashStat.Org also provides data on which intersections are the worst by borough and in the city as a whole. The neighborhood I covered in RW1, for example, had one of the worst intersections in Brooklyn and there had been advocates pointing at this site to get city officials to ticket more, change the intersection design and prioritize pedestrian safety.
I think that one problem with the Crash Stat site is that it is an advocacy site. It’s run through Transportation Alternatives, which is a very green, almost anti-car organization. You’ll notice on the map that no car accidents are displayed. I find this rather unfair. Yes, cars are the vehicles that are killing pedestrians and cyclists, but cars can also hurt other cars and the drivers in those cars. Wouldn’t it be even more effective if CrashStat.org could also prove more accidents between cars instead of between cars and people?
Overall, I think that the website says a lot about what you can do with Google Fusion Tables and how it can be used in a political, yet informative way.
A Year in J-School 
I think that crashstat.org is in some ways a perfect example of how data can be used to tell a story. You rightly point out that they omit car-to-car accidents on this map, but, of course, Transportation Alternatives’ “story” is about the dangers that car traffic poses to pedestrians and cyclists.
Overall, I think this is a clean, and very useful visualization interface, though I had some trouble understanding how to use the timeline. I also think they could have been more consistent in designing their key, which uses size AND color gradations in indicating the number of accidents, yet is not carried over to the fatalities markers.