Map of the Week: Bike accidents
(July 11: The pedestrian and cycling accident maps worked fine on their own as embedded maps, but something about displaying them both on the same page made many browsers very unstable. They’re now linked below.)
This week, we map 1,068 bicycle accidents reported to Toronto police in 2008. The data came to us from the Toronto transportation department, which analyzes accident reports they receive from the police.
Bike accidents seem to cluster in the area west of downtown, especially on College between Spadina and maybe Dufferin, and Queen between Spadina and Ossington. Dundas, King and Bloor have fewer, though Bloor between Avenue and Bathurst has more. To the east, the Bloor cluster ends abruptly at Jarvis.
(The equivalent part of the east end, which is similar in urban design, has far fewer bike accidents, though accidents do cluster on the Danforth between Pape and Broadview.)
Bay between College and Bloor also seems to have a cluster, as do major streets in the downtown area south of Dundas and north of Adelaide or so.
Time didn’t allow an overlay showing bike lanes. (Maps can be found here and here) Informally, though, accidents seem to cluster where bike lanes aren’t, and vice versa. Exceptions seem to be the College bike lane and a stretch of the Dundas St. E. bike lane west of Pape, where there is nearly one accident per block.
110 intersections had more than one accident (the great majority with two). Here are the top nine:
7 Bay and Dundas
7 College and Crawford
5 Queen and Broadview
5 Yonge and Dundas
4 Bloor and Bathurst
4 Bloor and Keele
4 Spadina and Dundas
4 Islington and the Queensway
4 King and John
The large number of points created a challenge. Our normal method of loading them into an XML file created a map which was slow to load and reload at a different zoom level, and also slow to manipulate, even in Firefox. In IE it was worse.
Our alternative, loading a KML file into Google MyMaps, failed when it refused to keep loading somewhere in the mid-hundreds. MyMaps has limits, but it’s sometimes hard to see what they are other than by trial and error.
We ended up with Geocommons, the free service that the Vancouver Sun used for its parking ticket map.
In IE, it takes anywhere from 9 to 17 seconds to load, but as far as I can tell stays loaded once that has happened. The main difference, as far as I can tell, is that it uses Flash.
In any case, the look and feel of the map is different from what you may be used to seeing – let us know what you think in the comments.
The full-sized map can be seen here.
Next week, we will look at pedestrian accidents.