Report numberRA-2004-36
TitleGuidelines and recommendations for tackling traffic unsafety within impact assessment. Study of traffic unsafety in MER/MOBER and rol of other relevant policy instruments
AuthorsPascal Lammar
Published byPolicy Research Centre for Traffic Safety 2002-2006
Number of pages95
Document languageDutch
Work packageOther: Knowledge traffic unsafety

By considering traffic safety during the planning of projects expensive traffic safety measures can be avoided afterwards during the operation phase. A number of policy instruments can be used to this purpose. This report primarily focuses on the integration of traffic safety within impact assessment, in particular environmental impact assessment (EIA) and mobility impact assessment. 


Methodologically, a selection of environmental impact statements (EIS) and mobility impact reports are reviewed for traffic safety, as well the discussion of this aspect as the respective quality. Respectively, Flemish, Brussels and Dutch environmental impact statements were studied. Because there is no need to consider traffic safety for all projects requiring environmental impact assessment, the selection was limited to projects which result in the guiding (e.g. roads) or generation (e.g. big recreational or tourist facilities, industrial projects) of traffic. Within these projects traffic safety should get the necessary attention. Because there are no international regulations concerning mobility impact assessment, as opposed to environmental impact assessment, the review is limited to the Flemish situation. Following aspects were considered in the analysis of the selected EISs and mobility impact reports: separate or no separate discussion of traffic safety, identification of the specific section discussing traffic safety, discussion of traffic safety during the different phases of the project (current situation or reference situation, construction phase, operation phase) and the respective quality, focus on the traffic safety of the various road users and the respective quality, presence of a qualitative and/or quantitative assessment of traffic unsafety.


The analysis of the environmental impact statements and mobility impact reports indicates that traffic safety is seldom discussed in a homogeneous and structural way. There is an obvious lack of a coherent and guiding framework. The current guidelines for the discussion of traffic safety within EIA are very limited. Further elaboration of traffic safety within Flemish guidebooks is therefore recommended.


The analysis shows that traffic safety is seldom discussed separately in Flemish EISs, contrary to the situation in Brussels and the Netherlands. In the reviewed EISs there is variation in the sections used to discuss traffic safety. In Flanders especially the sections ‘Human (Environment)’, ‘Human (Environment)-Traffic’ and ‘Traffic’ are used, although according to the Flemish EIA guidebook traffic (un)safety should be discussed within the section ‘Human (Environment)-Health’. The review of traffic safety during the different phases of the project shows that traffic safety is not always discussed. In Dutch EISs, remarkably, almost no attention is given to the traffic safety situation during the construction phase. The discussion of traffic safety among the various road users is not evenly distributed in the studied EISs, with generally less attention to the vulnerable road users (i.e. pedestrians and bicyclists). The treatment of the different road users is best elaborated in Brussels EISs. Traffic unsafety is not often evaluated in a qualitative and/or quantitative way. When this is the case it is most frequently in EISs concerning traffic guiding projects in the Netherlands. In general, the discussion of traffic safety is most detailed in EISs of traffic guiding projects. The highest quality can be found in EISs concerning the construction and/or reconstruction of roads. The discussion of traffic safety is generally less detailed in EISs of traffic generating projects (especially for industrial projects). The discussion of traffic safety within Dutch EISs is, in general, more elaborated than in Brussels or Flemish EISs, often including a qualitative or quantitative assessment. In Brussels EISs the elaboration of traffic safety is generally more detailed than in Flanders.


The decree on environmental impact assessment of 18/12/2002 gives further impetus to the development of the EIA process and the development of guidebooks with as final objective offering a structural framework for treating all environmental and health aspects equally. This decree also offers a legal base to strategic environmental assessment (SEA). 


Due to the lack of guidelines for mobility impact assessment, the approach varies a lot. The analysis of the mobility impact reports shows that, in practice, the attention primarily goes to the traffic circulation and accessibility of the project, and that traffic safety is seldom discussed separately. Consideration of the current traffic situation and estimation of the traffic impact of the project is almost exclusively confined to car traffic. The elaboration of the traffic safety aspect is rather weak to moderate for as well the different phases of the project as for the various road users, mainly focusing on the consequences of car traffic. In the most mobility impact reports there is only a qualitative description of traffic safety and is a qualitative and/or quantitive assessment lacking.


Apart from environmental impact assessment and mobility impact assessment, both used in Flanders, other types of impact assessment are (recently) being used internationally. More specifically, sustainability assessment or sustainability impact assessment, considering all ‘sustainability’ aspects, and health impact assessment, focusing on all health-related aspects, are interesting since traffic safety is also addressed within these instruments. 


In addition, other policy instruments may be useful to increase traffic safety. Among others, environmental care systems and certification, safety care, company transport plans and (mobility) covenants seem particularly interesting. These instruments do not focus enough on traffic safety at present, although they offer the possibilities to integrate traffic safety on different levels. Traffic safety audits are a particularly interesting instrument to identify unsafe traffic elements during the early planning phase of a project.


Based on the structure of the EIA guidebook, this report offers a structural and methodological framework with as objective the stimulation of a homogeneous and qualitative discussion of traffic (un)safety within impact assessment. Both objective and subjective traffic safety are discussed, as well as the aspects that need to be addressed during the different phases of the project. The difference between traffic guiding and generating projects is taken into account as much as possible when formulating the guidelines and recommendations. The bottlenecks, hampering a good assessment of traffic unsafety, are discussed as well as what is necessary at the policy level to eliminate these bottlenecks. To allow a good (quantitative) assessment of traffic unsafety it is important to have accurate and detailed accident data as well as intensity or exposure data. Linking accidents and road elements offers the opportunity to select those elements which are preferably applied to the project design. To allow this, data of the different road elements need to be available. To do a quantitative risk assessment only limited figures are available in Flanders at this moment.   


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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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