Report numberRA-2004-38
TitleRisk analysis of thoroughfares
SubtitleRoad safety in the built environment
AuthorsKurt Van Hout
An Dreesen
Rob Cuyvers
Published byPolicy Research Centre for Traffic Safety 2002-2006
Number of pages90
Document languageDutch
Work packageOther: Infrastructure and space

This report is the first part of a risk-analysis concerning the Flemish regional roads inside the built-up environment. First we give a rough sketch of the traffic safety situation on these roads. The built-up environment is characterized by a great road risk (accidents per km road length). Fortunately the seriousness is low compared to road types outside the built-up environment.


Next we look into the elements dat describe the built-up environment. These can be grouped into a number of scale levels: throughroads as part of a broader surrounding, the throughroad as a whole, the cross section of the throughroad and the throughroad as a sequence of specific locations. Then there are some characteristics that can be hardly ccategorised.


This classification is the basis voor de further arrangement of the report. For every scale level a chapter is spent to the traffic safety effects of the different characteristics and solutions. The international literature is screened with this purpose. When available guide numbers for the road design are included. These are however rather rare and often only qualitative. Often they are obtained based on other considerations as e.g. comfort as well. On some of the elements the literature provides rather great consensus. For other characteristics however it is far from clear what the safest solution is. Furthermore the research is often fragmented and exemplary and isn’t repeated elsewhere.


Road and environment characteristics with a (possible) important impact on traffic safety are intersection density and the number of (private) entrances. The parking situation is an other important factor. Only parking along the roadside can be tolerated on roads with a speed limit exceeding 30 km/h. A parking prohibition near intersections and crossings is also favourable for traffic safety.


Vulnerable road users deserve special attention. A great deal of the papers concern this group of road users. A better visibility and attentiveness (of all road users) are positively related to traffic safety. Several solutions are available.


From these papers we learn that there is hardly such a thing as the best solution. The best solution is indeed strongly influenced by the circumstances (surroundings, road users). The question remains e.g. if bicyclists should be mixed with motorised traffic or not. This depends on e.g. the type of bicyclist: An experienced bicyclist behaves differently compared to the unexperienced young cyclist or the elderly bicyclist with limited capabilities. It is clear however that they are kept in the visual range of the motorist. Two way cycle paths are not done in the built-up environment.


Foot paths on the other hand are (practically) always considered appropriate. A wide median increases the traffic safety for crossing pedestrians. There are a great number of crossing facilities available for pedestrians. The safest solution depends on the specific circumstances. Visibility and attentiveness are again keywords. Crossings near intersections should be situated as close to the crossing road as possible.

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The Policy Research Centre for Traffic Safety carries out policy relevant scientific research under the authority of the Flemish Government. The Centre is the result of a

cooperation between Hasselt University, KU Leuven and VITO, the Flemish Institute for Technological Research.


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