Updated: 10/12/2012 at 12:12 pm

The death of cyclist Neill Townsend in downtown Chicago Friday morning who, to prevent being doored by a parked car, ended up being hit by a passing semi truck, has drawn outcry from individuals inside and outside the biking community, as Chicagoans grapple with how to best prevent these accidents in the future.

Many commented on WBEZ’s story about the accident that an increase in protected bike lanes in the city would prevent doorings, while others weren’t sure that a protected bike lane would make much of a difference, and that alertness on the part of bikers and drivers would do the most to prevent accidents. 

WBEZ obtained data from the Illinois Department of Transportation, Division of Traffic Safety from 2009 through September 7, 2012 of this year, to see exactly where these dooring accidents are occurring — and what type of accidents they result in. There have been 577 reported doorings during that time period.

Observations from the map below are relatively clear: doorings most commonly occur on diagonal streets and intersections, particularly Milwaukee and Lincoln Avenues, as well as on Clark Street, all of which are heavy thoroughfares for commuters.

Additionally, a huge majority of doorings happen on the North Side of the city, which may say more about where Chicago’s population of bikers lives than the danger of North Side streets, though there are also small pockets of accidents on the South Side, like in the Hyde Park neighborhood where the University of Chicago is located.

Here’s a chart of under what conditions doorings are taking place. The majority are under optimal conditions — clear skies, daylight and no rain or ice, indicating that doorings are less the result of potentially dangerous scenarios, and more dependent on human action and behavior.

Elliott Ramos and Alex Keefe contributed reporting to this story.