Access management in Safer Transportation Network Planning

This report is one in a series of publications, used in the development of the network planning tool ‘Safer Transportation Network Planning' (Safer-TNP). The publications were used to guide the development of planning structures, diagnostic tools, planning recommendations, and research information in the computer tool Safer-TNP. Safer-TNP is a design tool that guides network planners in designing safe transportation networks (or improving safety of existing transportation networks). It provides the practitioner with diagnostic tools, and guiding information. At the moment of publication of this report, Safer-TNP is still being developed. Besides this ‘Access management report', the following reports have been published in this series: -Route management in Safer Transportation Network Planning (Hummel, 2001a) -Land use planning in Safer Transportation Network Planning (Hummel, 2001b) -Intersection planning in Safer Transportation Network Planning (Hummel, 2001c). The information in this report will be used to guide the structure and the programming of different parts of the Safer-TNP tool with respect to access management. Described is, in a step-by-step procedure, what information is needed, and in what way the information should be processed. In the last chapter of the report, background information is provided to give users of the tool guiding information. Because of the specific purpose of this report, its structure and style deviate somewhat from regular research reports. Because the different chapters are used in different stages of the development of Safer-TNP, there is some repetition of information. Furthermore, the information is written in telegraphic style, to simplify the electronic packaging of information in Safer-TNP. In this publication, several access management techniques and their effects on safety and traffic operations are described. The purpose of the techniques is to provide appropriate access to land use, while preserving the capacity and safety of the road network. Access management is proved to be an effective technique for improving traffic safety, because of the exclusion of hazardous manoeuvres and stabilization of traffic flow. The following techniques are discussed: -Access spacing -Corner clearance criteria -Median alternatives -Left-turn lanes -U-turns -Access separation at interchanges -Frontage roads.