Idea: mapping bicycle collisions in Cape Town

31st July 2016 - city mobility | mobilité urbaine / city writing | écritures urbaines / urban cycling | vélo urbain / urban notebook | cahiers urbains

Idea for future work: what if we mapped all the cycling collisions in Cape Town over the last 5-10 years? What… Click To TweetFichier_000

I would like to establish a Google Map on which all of the cycling collisions (and muggings, and bikejackings) reported in the media can be mapped and tracked. There can be no doubt that such a map (if one doesn’t already exist – please DM me on Twitter or comment here, if so) would start to produce valuable data about the kind of streets that kill, in our city.

In particular, I expect that the timing of crashes, plotted in space, would show that certain sidewalk-free arterial roads (which are often the only choice for cyclists moving across parts of the city, due to #automobility) are consistently fatal, even if the gap of months or years between fatalities allows individual tragedies to fade from public awareness.

I, for one, am aware of a steady stream of deaths, but can’t easily recall where the last, or next-to-last, crash took place. It is very unlikely that the police would have such figures.

When I have time, the steps I propose would thus be:

  1. Determine what mapping platform (if not Google Maps) would best suit such a project (for the preliminary mapping phase).
  2. Contact the SAPS and other sources, requesting all the cycling collision data they have. Put out a few public calls for same.
  3. Analyse PPA and other sources and archives for collision data going back 5-10 years
  4. Plot these points in GIS, once the analysis is complete, for a secondary mapping phase. Cross-reference cycling collision points with posted speed, slope, time of day and other spatial data to come up with a statistical argument.
  5. Present these findings back to the CoCT.


  1. Jennifer Louisa Baufeldt says:

    Hi Brett,

    I would love to see your results. Would I be able to get a copy of them?

    • Brett Petzer says:

      Hi Jen,

      Certainly! I have just obtained your piece, ‘Investigation and Gap Analysis of Selected Cycling Upgrades in Cape town and the New NMT Facility Guidelines’, as well as your dissertation, and will read them with great interest! I will let you know when I have finished my dissertation (October). In the meantime, it would be good to be in touch for all things cycling. Best, B.

Leave a Reply

Your email address will not be published. Required fields are marked *