Tiêu chuẩn quốc tế

• Số hiệu / Standard Number: AASHTO FHD:2004
• Năm ban hành / Publication date: 2004
• Tình trạng / Status: A - Còn hiệu lực
• Tên tiếng Anh / Title in English: A Guide to Achieving Flexibility in Highway Design
• Số trang / Page: 140

Phạm vi áp dụng / Scope of standard

introduction

Context-sensitive solutions (CSS) are an emerging concept in
highway project planning, design, construction, and maintenance in
recent years. CSS reflects the need to consider highway projects as
more than transportation. CSS recognizes that a transportation
facility, by the way it is integrated within the community, can
have far-reaching impacts (positive and negative) beyond its
traffic or transportation function. The term CSS therefore refers
to an approach or process as much as it does to an actual design or
solution.

The term Flexibility in Highway Design was adopted by
the Federal Highway Administration (FHWA) in their groundbreaking
publication (issued in 1997) that demonstrated how agencies could
accomplish the objects of CSS within accepted design processes and
criteria. The core theme of the FHWA publication was flexibility-in
design approaches, use of criteria, execution of design solutions,
and incorporation of special or "unique" features:

This Guide [Flexibility in Highway Design] encourages
highway designers to expand their consideration in applying the
Green Book criteria. It shows that having a process that is open,
includes good public involvement, and fosters creative thinking is
an essential part of achieving good design.

The terms context-sensitive solutions, context-sensitive design,
and flexibility in highway design are used interchangeably by some.
Other terms expressing the concepts include place-sensitive design
and Thinking Beyond the Pavement. These terms all refer to the same
process and result: a highway or transportation project that
reflects a community consensus regarding purpose and need, with the
features of the project developed to produce an overall solution
that balances safety, mobility, and preservation of scenic,
aesthetic, historic, and environmental resources.

A national conference sponsored by the Maryland State Highway
Administration and FHWA in 1998 produced a definition of
context-sensitive design that has been adopted by many:

Context sensitive design asks questions first about the need
and purpose of the transportation project, and then equally
addresses safety, mobility, and the preservation of scenic,
aesthetic, historic, environmental, and other community values.
Context sensitive design involves a collaborative,
interdisciplinary approach in which citizens are part of the design
team.

CSS or flexibility in highway design therefore represents a
comprehensive process that attempts to bring all stakeholders
together in a positive, proactive environment with the objective
being the completion of projects that meet transportation needs and
are viewed as improvements or enhancements to the community through
preservation efforts and sensitivity to local values. CSS
recognizes the need to consider that transportation corridors may
be jointly used by motorists, pedestrians, cyclists, and public
transit vehicles. In addition to the movement of people, CSS also
considers the distribution of goods and the provision of essential
services.

The values presented in this guide do not imply that the
existing streets and highways are unsafe, nor do they mandate the
initiation of improvement projects. This guide is not intended to
be a detailed design manual that would supersede the need for the
application of sound principles by the knowledgeable design
professional, nor is it intended to establish guidelines, criteria,
or standards for the design of roadways. The use of the terms
guideline or criteria in this document are not to be
considered as a substitute or synonym for the word standard.