This text provides guidance on the geometric design of highways and streets, based on established practices and supplemented by recent research. It is also intended to form a comprehensive reference manual for assistance in administrative, planning, and educational efforts pertaining to design formulation. The intent of this policy is to provide guidance to the designer by referencing a recommended range of values for critical dimensions. Sufficient flexibility is permitted to encourage independent designs tailored to particular situations. Minimum values are either given or implied by the lower value in a given range of values. The larger values within the ranges will normally be used where the social, economic, and environmental impacts are not critical. Emphasis has been placed on the joint use of transportation corridors by pedestrians, cyclists and public transit vehicles. Designers should recognise the implications of this sharing of the transportation corridors and are encouraged to consider not only vehicular movement, but also movement of people, distribution of goods, and provision of essential services. Cost-effective design is also emphasised. The traditional procedure of comparing highway-user benefits with costs has been expanded to reflect the needs of non-users and the environment. Although adding complexity to the analysis, this broader approach also takes into account both the need for a given project and the relative priorities among various projects. Design guidelines are included for freeways, arterials, collectors, and local roads, in both urban and rural locations, paralleling the functional classification used in highway planning. The book is organised into functional chapters to stress the relationship between highway design and highway function. These guidelines are intended to provide operational efficiency, comfort, safety, and convenience for the motorist. The design concepts presented herein were also developed with consideration for environmental quality. The effects of the various environmental impacts can and should be mitigated by thoughtful design processes. This principle, coupled with that of aesthetic consistency with the surrounding terrain and urban setting, is intended to produce highways that are safe and efficient for users, acceptable to non-users and in harmony with the environment. Chapter titles are as follows: (I) Highway Function; (II) Design Controls and Criteria; (III) Elements of Design; (IV) Cross Section Elements; (V) Local Roads and Streets; (VI) Collector Roads and Streets; (VII) Rural and Urban Arterials; (VIII) Freeways; (IX) At-Grade Intersections; and (X) Grade Separations and Interchanges. (A)
Samenvatting