Normative standards in the Dutch guidelines for road design; Actualization of the normative human being and design vehicle. Roads are designed according to guidelines for road design. These guidelines are based on certain benchmark standards: after all, it is stands to reason that a road is designed and constructed in such a way that vehicles and road users have sufficient space to safely make use of the road with the smallest possible number of conflicts. The (geometric) design takes into account the (physical and mechanical) characteristics of vehicles and also the (physical and psychological) characteristics of road users. This is done by applying design vehicles and persons (normative people). These are not only an average vehicle or human being, but also the extremes, for example an extra-large vehicle and/or a disabled road user. This report gives an overview of a number of design vehicles and describes how these were incorporated in the guidelines. In its publication 279 (http://library.swov.nl/action/front/cardweb?id=330021), the Information and Technology Platform for Infrastructure, Traffic, Transport and Public space (CROW) defines different standard (design) vehicles and characteristics that are of interest for not only road design but also, for example, for traffic management. The guidelines for urban and rural roads should comply with these recommendations. This report gives insight into the extent to which the recommendations have been included in the guidelines. In addition, the report includes new data. Because of the limited scale of the project, not all types of design vehicles are discussed, but the focus is on the passenger car, truck, bus and pedestrian. The publications ASVV (CROW, 2012a, http://library.swov.nl/action/front/cardweb?id=336526 ) and the Road Design Manual for rural roads (CROW, 2012b) have been screened using a number of search terms to find out to what extent the characteristics of the normative vehicles as defined in CROW-publication 279 have been complied with. It was found that the recommendations of CROW-publication 279 have for the most part been incorporated in the review of the two guidelines, but that there are still some deviations. This is particularly the case in Road Design Manual for rural roads. With regards to data on the physical and psychological characteristics of human beings, characteristics that are discussed in CROW-publication 279 are not always mentioned in in all versions of the guidelines. Generally, the Road Design Manual for rural roads contains less information about the characteristics of the human being than the guidelines for urban roads (ASVV). Some guidelines discuss characteristics of human beings in relation to infrastructural facilities without mentioning specific values that should be used for that purpose. Often the background relating to the source of the values are missing and also the context of various parameters in relation to design are not always provided. However, in some versions of the guidelines we find specific values of an attribute (for example, the precise eye height of cyclists) without any explanation as to how this characteristic should be taken into account in the design of infrastructure facilities. Deviations have also been found with regards to vehicle characteristics. For example, in the Road Design Manual for rural roads a width of 1.75 meters is recommended for a passenger car when designing the cross-section of a road , whereas the actual width of the passenger car design vehicle is 1.83 metres. The Directorate-General for Public Works and Water Management and some other road authorities believe that the characteristics and properties of designs vehicles in the guidelines are not always up to date. The present exploratory study has shown that this presumption is for the most part unfounded. There is also the suspicion that the guidelines do not always adequately specify which standards are used or how these have been derived. This suspicion was found to be partly justified. The document providing the underlying data for design vehicles (CROW-publication 279) lacks a solid underpinning of the calculation method and the recommendations that are made. The various design guidelines have adopted the majority of the recommendations from this publication. However, the guidelines are not reviewed systematically to determine whether the recommendations have consistently been incorporated. It is recommended that this is given explicit attention in future. This could be an explicit task for CROW or the working groups that is given the responsibility for revision of the guidelines.
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