| Contextual
Infrastructure Planning and Design |
| Making Highway Design
More Context Sensitive: Key Challenge in the New Millennium |
| By Hal Kassoff, Washington, D.C. 1-202-783-0241, kassoff@pbworld.com
|
| In many areas around the
world, highway planners and designers are recognizing that meeting
community, environmental, and aesthetic requirements must be on a
par with meeting the functional requirements of safety and capacity.
As this becomes common practice, we are seeing that additional costs,
if any, are typically far outweighed by the benefits and increased
public support that are gained. |
|
| Highways are a major physical presence in the areas they traverse.
Their impacts on surrounding communities are significant and long-standing.
Unfortunately, sufficient care has not always been taken to ensure
that the design of a highway enhances the aesthetic and environmental
quality of its surroundings.
The highway design process has traditionally emphasized achieving
required functionality at the lowest possible cost. While this goal
remains important, it has become increasingly clear that other factors
contribute equally to gaining acceptance for highway improvements.
Paying close attention to environmental impacts; committing to avoid,
minimize and/or mitigate these impacts to the maximum extent possible;
and even finding ways to provide environmental improvements over
existing conditions have become prerequisites for winning local
community and environmental resource agency support. Also, the visual
impacts of a highway project-how well it fits into its setting,
how pleasing its appearance, how compatible it is with its neighbors-have
come to have a major bearing on the project's acceptance or rejection.
Context is the Key
Transportation planners and highway design professionals are increasingly
aware that the basic process by which highway improvements are planned
and engineered is changing. They are embracing the notion that environmental
and aesthetic issues, once treated as "externalities,"
must be dealt with as an integral part of the process from the outset.
In other words, the entire design process must become more context
sensitive.
The key to context sensitive design is having a thorough understanding
of the context itself. This concept is more subtle than might be
first imagined. There is the obvious visible, physical context that
is quite important, but there is also a not-so-obvious context of
values, culture, tradition, politics and expectations. This is the
context of people-stakeholders who in one way or another are affected
by the implementation of a project. Understanding both contexts-visible
and invisible-is essential to producing a successful design in any
medium.
Substantive and continuous interaction with affected stakeholders
in the planning, environmental, and design phases of major projects
is one way to ensure that the "context" becomes clearly
defined. In fact, in the U.S. this interaction has become a requirement
for projects to remain eligible for federal funds. Beyond federal
requirements, however, involving the public in the process is the
right thing to do and the smart thing to do. [Ed. note: See also
"Best Practice
Community Consultation: Advice to Project Managers" by
Fiona Court.]
There is no better way to build public trust than to establish open
two-way communication in a project's earliest stages. Context sensitive
design with active community involvement will not win over those
who are unalterably opposed to a project, but it can help to gain
the support of others who want to be certain that their concerns
are being addressed adequately. It will also strengthen prospects
for the project with environmental permitting agencies and elected
officials.
Will Context Sensitive Design Sizzle or Fizzle? Issues of Standards,
Liability and Cost
Mention the term "context sensitive design" to a highway
design engineer and you're likely to evoke one of three reactions:
- "...A positive approach that helps win support for essential
projects."
- "...It undermines a proven engineering approach and
compromises safety."
- "...It's nothing new, we've been designing highways that
way for years."
Few highway designers have nothing to say about the subject. Among
their most significant concerns are questions of standards, safety,
liability and cost. These concerns must be addressed if the philosophy
of context sensitive design is to gain broad acceptance in the highway
community.
Standards and Safety. Fortunately, resources
that foster context sensitive design are already available to highway
designers and owners. For a number of years in many European countries,
great attention has been given to the aesthetics of highway design
and how it fits into the landscape. In the UK, for example, a number
of documents are used, such as the Highways Agency's The Good Roads
Guide, which consists of six sections with a total of fifteen parts
that relate to considerations such as land form and alignment, nature
conservation management, archaeological mitigation, and much more.
In addition, the National Assembly for Wales has published design
guides on roads in lowland areas and roads in Upland Areas. [Ed
note: see also "Flexibility
in the Geometric Design of UK Highways," by Ian Wilson.]
In the U.S., the American Association of State Highway and Transportation
Officials (AASHTO) green book of highway design standard includes
considerable flexibility to accommodate context sensitive goals as
well as safety goals. Hopefully, future updates of the green book
will formally embrace the key principles and concepts of context sensitive
design.
In 1998, the Federal Highway Administration (FHWA) demonstrated support
for context sensitive design with its publication of "Flexibility
in Highway Design," which contained numerous examples of the
kind of flexibility already inherent in the AASHTO green book. An
AASHTO task force is working on development of additional chapters
on liability and safety intended to address deficiencies perceived
with the FHWA "Flexibility" document.
Liability.
When standards are considered and reasonable engineering judgments
are made and documented, concerns over liability can be minimized.
The goals of a forgiving system for drivers are not inconsistent with
the goals of context sensitive design as long as the design is in
harmony with both driver and community expectations.
In the U.S., a key issue involves potential liability for not adhering
strictly to maximum achievable green book standards. This is a sensitive
point with designers who may have spent hours preparing for litigation
that challenges their professional judgment and competence, and exposes
them and their employers to financial damages and sanctions. Not a
pleasant experience!
The key to the liability question has always been what is achievable
within reason. It is not possible to apply maximum standards in all
situations. We build tunnels with no shoulders. In mountainous areas,
we accept steeper grades and sharper curves. In urban areas, we accept
lower speeds and narrower lanes. It is common to adjust design standards-and
driver expectancy-based upon context.
Making tradeoffs and applying engineering judgment have always been
essential components of the highway design process. When achieved
with engineering skill that clearly reflects a driver- expectancy
approach and a concern for safety, such judgments are not likely to
be found deficient.
Cost. The cost factor is, of course,
another major consideration. Designs that are sensitive to the environment
and aesthetically pleasing are not always achieved at the absolute
lowest cost. On the other hand, increased costs to implement designs
in harmony with the natural and human environment are typically only
a small percentage of the total project cost.
For example, coordinating and, where appropriate, integrating the
design and surface treatment of retaining walls, sound barriers, bridge
piers and abutments can provide a significant aesthetic benefit without
affecting costs dramatically. Moreover, the benefits generally outweigh
any increased costs in terms of public and resource agency acceptance,
particularly if contentious and costly delays can be avoided.
Heading in the Context Sensitive Direction
In many European countries, context sensitive design has been embraced
and practiced for several years. In the U.S., AASHTO's immediate past
president, Tom Warne from Utah, embraced context sensitive design
as one of his emphasis areas. AASHTO Executive Director, John Horsley,
is a strong advocate as well. With this policy level support from
AASHTO's leadership and from FHWA, and with the Subcommittee on Design
developing additional material that the majority of design engineers
can buy into, it is generally expected that the philosophy underlying
context sensitive design will take root in the U.S.
To help the process along, National Cooperative Highway Research Program
(NCHRP) project 15-19 is producing a guide for the "Application
of Context Sensitive Design Principles." NCHRP 20-7/114 is looking
at "Context Sensitive Design for Integrating Highway and Street
Projects with Communities and the Environment," and NCHRP 15-22
is addressing "Safety Consequences of Flexibility in Highway
Design."
In his recent report to AASHTO, Parker Williams, Maryland's State
Highway Administrator and chair of a training steering committee to
advance context sensitive design, reported significant efforts are
under way in more than half of the states toward implementing context
sensitive design practices. The Departments of Transportation in five
states--Connecticut, Kentucky, Maryland, Minnesota and Utah-have agreed
to "pilot" the advancement of context sensitive design principles
and practices and to serve as models for other transportation agencies
throughout the U.S. (see next
article).
While it would be a mistake to assume that context sensitive design
will reflect the mainstream among highway designers in the immediate
future, what seems clear is that the trend among design engineers
throughout the world is to take more of a context driven approach
when developing alternatives and searching for solutions. The continuing
challenge will be to achieve such solutions while satisfying reasonable
safety and functional requirements.
In the final analysis, context sensitive design involves common sense.
There is an undisputed need for safety in the design of highways.
There is an accepted need for standards. There must be consistency
and uniformity in the application of traffic signs and markings so
they mean the same thing no matter where they are applied. Costs must
be kept within reasonable bounds. But none of these ideas is incompatible
with the concept of producing highway designs that are, in the end,
sensitive to and in harmony with the context in which they reside.
Around the world, highway designers can also rely on the talents of
colleagues in related disciplines, and the opportunity for dialogue
with and feedback from constituents and stakeholders to contribute
to making context sensitive design the preferred way of developing
a project. |
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| As PB’s Highway Program Area Manager,
Hal Kassoff has actively promoted the concept of context sensitive
highway design. working with several PB professionals who have volunteered
their time, he is sponsoring development of a reference guide, Concepts
in ContextualHighway Design, for use by PB and its clients. Hal served
as state highway administrator in Maryland for 12 years before joining
PB. During that time, he was a champion for “humanizing”
the highway environment. Under his leadership and since then, Maryland’s
state highway administration has been recognized with numerous awards
for environmental sensitivity and aesthetic designs.
[Ed note. This article was adapted from an article that appeared
in the February 2000 issue of Roads and Bridges and another that
appeared in the January/February 2000 issue of World Highways.] |
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