Where do accidents happen?
There is currently some debate in Edmonton regarding bike lanes, and the inconvenience that they will provide to drivers. In particular, Mayor Mandel was quoted as saying:
Not that they’re not a good idea, but it just seems someone behind your scenes out there has just decided we’re going to eliminate all vehicles and only have bikes.
In response, I wanted to look at the number of interactions that cars have with bike or pedestrian in Edmonton. The data.edmonton.ca portal had the appropriate data from 2010 - intersection collisions here, and midblock collisions here. I sorted the data for pedestrian and bicycle collisions with vehicles, and I included all data for bikes and pedestrians, regardless of who was deemed to be a fault. I loaded the CSV data into Cartographica, a lightweight Mac based desktop GIS, and used OpenStreetMap as the base layer for Edmonton. The results are below, captured as an image (I will work with someone more capable that me to check the data and to get it on line in an interactive format). Legend: red/yellow diamonds are intersection collisions, blue/blue diamonds are midblock collisions. The numer adjacent to each diamond represents an aggregate of pedestrian/bicycle interactions with motor vehicles. .
Some things to note:
- More collisions happen at intersections (90 in total) than midblock (22 in total).
- The most dangerous intersection in 2010 was Fort Road and 66 Street, with 4 collisions.
- The most dangerous stretches of road were Gateway BLVD north of 51 Ave, 109 Street north of Whyte, and Calgary Trail north of 34th Ave.
- Midblock collisions saw 18 pedestrians and 4 cyclists injured.
- Intersections saw 65 pedestrians and 27 cyclists injured.
There is a greater safety issue at intersections where advanced pedestrian and cyclist activated lights should be installed in conjunction with bike lanes. Furthermore, if the bike lanes are being considered for safety reasons, residential street speeds should be lowered from 50 km/hr to 30 km/hr. There is convincing data that cars travelling slower inflict less damage than tose travelling faster - see this WHO report [PDF].
Finally, if the City of Edmonton were serious here, they could conduct an interesting study to track accident rates with cyclists and pedestrians give the introduction of bike lanes, intersection controls and low residential speed limits.