In the report of late 2001 Safe, What is Safe?, SWOV indicated how the annual number of traffic casualties could be reduced considerably. These proposals were to be regarded as an addition to the proposals as were developed in the then National Traffic and Transport Plan of the Ministry of Transport. In Safe, What is Safe?, besides a speeding-up of the construction of a sustainably-safe infrastrucure, a qualitatively better implementation was advocated. During the last few years, the introduction of Sustainably-Safe has become widespread. What the layout of a sustainably-safe road infrastructure should preferably look like has, in the meantime, become generally well known; it can be found in various publications about this subject. Apart from this, it should be noted that, for by no means all layout elements, is known precisely a) how they influence the accident chance, and b) the extent to which this chance would change if a preferable layout was deviated from. A second problem yet to be solved is that not all Sustainably-Safe principles have been transformed into design requirements. In particular, requirements for being able to plan sustainably-safe road networks are missing. A third problem refers to the realisation of a sustainably-safe infrastructure. In practice it seems that it is not always so simple to meet the requirements and to decide whether the actual, practical experiences already indicate the need to modify the requirements. The underlying question in this is whether a greater road safety improvement in the Netherlands can be achieved if a higher quality implementation of a sustainably-safe infrastructure was achieved. This study attempts to investigate the extent to which the current and planned road infrastructures meet the Sustainably-Safe requirements. To do this, both the network features (road categorizing) and the road segment and crossroads features have been tested. This testing was carried out in a region in the Netherlands (part of the southern province of Limburg). Based on this sample, there is, at the most, an indication for the situation in the whole country; there is no reason to suppose that the situation in that part of Limburg differs widely. SWOV has formulated new draft requirements for network features. These additional requirements concern the function of a connection in an area, the crossroads type, the detour factor, and the route choice. SWOV recommends including these requirements in the next review. Our study shows that, to a large extent, the tested network meets the requirements made. However, it is striking that only a limited number of intersections of two distributor roads now meet the current requirement, namely a roundabout. In this study, an extensive addition to the layout requirements was also drawn up for crossroads and road sections. Most of these requirements can be traced back to the requirement that certain conflicts on a Sustainably-Safe road category should not occur and, if a conflict cannot be avoided, only small speed differences are permitted. SWOV hereby recommends that these extra features be added to the existing requirements. Our study shows that the tested road network sometimes scores well, whereas other features score less well. That is why SWOV recommends examining why there is such a large spread in the results. In this situation, SWOV further recommends, for a limited number of requirements (namely those for which there are strong indications that they have a relation with severe accidents), that such agreements be made that they will always be met. The present study indicates that there is a need for such agreements.
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