GIS and bicycle safety

Today and tomorrow the “4th International Cycling Safety Congress” (ICSC internet) takes place in Hannover, Germany. This is an excellent opportunity to learn from and connect to experts from various domains. The common denominator is, as the conference name indicates, bicycle safety, but the approaches presented so far are rather diverse.
Today’s presentations ranged from medicine (which body parts are most often injured in different types of crashes), to legal aspects (single- or bidirectional cycle paths), to hardcore technology (automatic analysis algorithms for videos from naturalistic studies) to planning (optimal road design, especially at intersections) and to social and psychological aspects (by which values and attitudes are ‘cyclists’ driven).

What was largely missing so far was the spatial perspective on bicycle safety. Hence I’m looking forward to add a nice, little piece to the multi-disciplinary mosaic tomorrow.
My argumentation starts from the fact, that bicycle accidents are spatial by their very nature. They don’t occur in the nowhere, but in geographical space. Thus they can be analyzed in Geographical Information Systems (GIS). Through geospatial mapping and analysis geospatial patterns and dynamics become obvious, as the figure below demonstrates.

Spatial dynamics of bicycle accidents in the city of Salzburg between 2002 and 2011.

Spatial dynamics of bicycle accidents in the city of Salzburg between 2002 and 2011.

From bicycle crash frequency to risk estimation.

From bicycle crash frequency to risk estimation.

Although the spatial patterns and dynamics that emerge from simply putting the crash locations on a map are interesting and relevant for multiple application contexts, the estimation of risk is even more helpful. The problem here is, that exposure variables are hardly ever available beyond the city scale.
In order to account for the variation of crash occurrences and the corresponding risk within the city we made use of the recently developed (and published internet) bicycle flow model for the city region of Salzburg. Relating the city’s reported crash locations to the simulated bicycle traffic volume results in an estimation of risk at the smallest possible scale.

Besides the analysis of (historical) crash data, Geographical Information Systems are also capable to model and simulate potential safety threats. For my presentation I’ve selected three use cases in which such a geospatial model (Loidl & Zagel, 2014 internet) is employed in decision support and planning tools:

  • The first use case is about the quality of accessibility of central facilities, such as university buildings. The introduced assessment model allows for an evaluation of the immediate environment of the respective facility. Based on this status-quo analysis, existing corridors and barriers as well as potential connections can be identified.
  • In the second use case, the assessment model is fed into an interactive, simulation environment (see Wendel, 2015 internet for further details). Through a web interface the effect of infrastructural or legal measures on the overall safety index can be tested very intuitively.
  • As a third prototypical field of application, besides status-quo analysis and simulation, the assessment model is employed in a bicycle routing service. Operated by the city and the federal state of Salzburg, the web portal radlkarte.info internet recommends the optimal (safest, most comfortable) route for utilitarian bicyclists.

What all examples, shown in the presentation, have in common is that they make use of the spatial characteristics of bicycle crashes and the transport network respectively. Geographical Information Systems can thus be considered as well-performing integration platform for multiple perspectives on the complex system of bicycle safety and as facilitator for innovative planning and information tools.
Have you got any comments, ideas or critical remarks? Feel free to write a comment, use the contact form or simply get connected on Twitter internet.

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One comment

  1. Pingback: International Cycling Safety Congress 2015 | gimobility

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