AASHTO - American Association of State Highway and Transportation Officials
Scope
The scope of this guide includes planning@ design@ and operation of both existing and new pedestrian facilities. Although these guidelines can be applied to existing pedestrian facilities@ it is usually most practical to implement these guidelines when a new facility is constructed or an existing facility is being reconstructed. This guide is not intended to set forth strict standards@ but to present sound guidelines that provide for the needs of pedestrians and other roadway users. However@ in some areas of the guide@ design criteria have been provided to indicate suggested minimums. Where deviations from these suggested minimums or from an agency's guidelines are needed@ the deviations should be considered on the basis of an engineering study and the rationale for not conforming to this guide or an agency's guidelines should be documented. The construction of a highway or street project@ including any associated pedestrian improvements@ is the culmination of a planning and design process that is often lengthy and complex@ and involves many agencies and individuals. During each step of the process@ important decisions are made that affect subsequent steps and the overall design outcome. This project development process has four distinct phases. State departments of transportation (DOTs) and other transportation agencies use a range of terminology to describe the process. For the purposes of discussion@ the following outlines the process and terminology: ? Concept Definition??The identification of a project@ including its need@ geographic limits@ community context@ and other specifics to enable feasibility studies to begin. ? Planning and Alternatives Development??The broad range of activities that balances competing interests@ resulting in the selection of a preferred plan that meets regulatory requirements and is sufficiently detailed to proceed with final design and construction. ? Preliminary Design??The initial phase in the final design process. ? Final Design??Completion of construction documents and specifications for the construction of a project.