Accidents in 4D

Accidents are happening in NRW…

The federal state of Northrine-Westphalia (NRW) is home to about 18 million people and thereby is the most populous German federal state. Furthermore, 28 of the 80 German major cities are situated in NRW. The Ruhr area is situated in the heart of NRW and is the moste dense metropolitan region in Germany. Also, the total street length amounts to about 20.000 kilometers making NRW’s street network one of the most lengthy ones in Europe  [vrvz2016]. Therefore, it is not surprising that there were about 27.0000 accidents in 2014 according to [wmsNRW2016].

… let’s give things a closer look

The mentioned circumstances let the research focus nextPlace visualize a small portion of the NRW accident data as Space-Time-Spheres. This aims at showing new contexts that have barely been visible before. In general, an accident is illustrated by a point. An accident, however, is always an extensive event, meaning that it is an event that is composed of the factors that comprise the accident site, such as road links and upcoming traffic. Furthermore, accidents often occur within distinct temporal conditions and are therefore depenedent on the aspect of time. The questions arises if accidents occur more frequently at different daytimes or times of the year within spatial proximity. The underlying idea is to use all the available information in order to assess the accident black spots identified by [strassenNRW2016]. The ultimate aim would be go get further insights into how to resolve these accident black spots.


The accidents are visualized through so-called “Space-Time-Spheres”. It is important to note that the phere’s diameter is equivalent to the spatial and temporal environment. The spere’s altitude is defined by the time the accident took place, 0 o’clock representing ground level and 24 o’clock representing the highest possible point (equates to 2.400 meters above sea level). The spheres are classified into three different colors; each color representing a different accident category:

  1. Green: Property damage
  2. Yellow: Injury to persons and property damage
  3. Red: Fatal injury to persons and property damage

The speres are being presented within the time of the accident and remain visible for about 3 months. A time regulator makes it possible to retrieve information even if months already passed by. A more detailed time regulator enables a person to retrieve the information of a certain time of the day.

New insights

The innovative visualization makes it possible to assess the accidents based on their spatial and temporal accumulations. Consequently, it is possible to clearly distinguish between the different temporal contexts of the accident black spots within a certain day or year.

Research demand

The three-dimensional depiction of four-dimensional data (x, y, altitude, time) via a two-dimensional medium (a computer screen) is not satisfying. Further informations could be assessed more effectively if they could be perceived stereoscopically. A real 3D medium, such as an augmented or virtual reality display, could enhance this.


[vrvz2016]: Verkehrsrecht Verzeichnis GmbH, last retrieved on July 11, 2016,

[strassenNRW2016]: Landesbetrieb Straßenbau Nordrhein-Westfalen, last retrieved on July 11, 2016,

[wmsNRW2016]: Straßennetz Landesbetrieb Straßenbau NRW (WFS), last retrieved on July 11, 2016,

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