May/June
2002
See
It Before It's Built
by
Richard E. McDaniel
Imagine
your client is the park superintendent for a national park. To help
move visitors in and out of the area, a new road needs to be built
to augment the existing one. You propose three design options: a bridge
that allows for an arch design, a high-clearance bridge requiring
long columns, or a low-clearance bridge. The client now needs to decide
which design would suit the park best.
Wouldn't
it be nice if the client could actually see the bridge—exactly
as it would look after construction and against the actual backdrop
of the park—before making a decision?
![Design visualization showing the location of a proposed trail](images/06dv1.gif) |
This
design visualization of the Natchez Trace Parkway in Mississippi
shows the location of a proposed trail meandering through woods.
|
The Federal
Highway Administration (FHWA) provided precisely that service for
the National Park Service's Natchez-Trace Parkway in Mississippi.
The park people were interested in a bridge spanning historic Old
Agency Road. But residents living nearby were concerned, among other
things, about the impact of constructing a bridge over this tree-lined
roadway. Paul Schneider, John Seabrook, and myself, all with FHWA's
Eastern Federal Lands High Division's (EFLHD) Location Branch, showed
them a dozen different options—using different bridge colors
and types. We also showed them what it would look like without any
landscaping, and what it will look like in 5 years after vegetation
has grown.
![Design visualization showing a bicyclist and the addition of bicycle lanes](images/06dv2.gif) |
Another
DV of the Natchez Trace Parkway, showing a bicyclist and the
addition of bicycle lanes.
|
These
days, clients do not need to attempt to visualize designs in their
minds, and they do not have to pay a fortune to obtain artist's renderings
of the various options. All they need to do is have their tech folks
produce a design visualization for the project.
Get
the Picture
Design
visualization (DV) technology enables engineers to depict how facilities
like bridges, roadways, sidewalks, and buildings will look after they
are completed. The DV images can be displayed on computer screens
or in large, high-resolution color photographs. To do this, the engineers
match a photograph of the construction location with a three-dimensional
(3-D) computer-generated model of the proposed design. What emerges
is a composite view of the proposed highway facility superimposed
on the photograph of the construction location. In addition to still
pictures, 3-D animation software makes DV video simulations possible
as well.
![Design visualization of a typical trail approach to a bridge crossing](images/06dv3.gif) |
This
DV shows a typical trail approach to a bridge crossing.
|
DV can
be used for any aspect of roadway design, including construction of
new bridges and roadways and modification of those facilities. Although
the processes used in DV have been available for some time, the technology
has become more feasible only in recent years— thanks to rapid
advances and falling costs in computer technology. Before the requisite
technology was available, the only way to produce visualizations was
for an artist to draw them by hand. Today, with high-end graphics
workstations and software available at reasonable costs, such manual
work is no longer required. And computer technology allows for much
greater precision compared with hand-drawn simulations.
![Photo of existing intersection at E Street and 19th St in Washington, DC](images/06exinter.jpg) |
This
photo of existing street conditions at the intersection of E
Street and 19th Street in Washington, DC, are part of a tunnel
feasibility study.
|
![Photo of 25th St and E St intersection in Washington, DC](images/06exw6.jpg) |
This
photo for the tunnel feasibility study shows existing street
conditions at the intersection of 15th Street and E Street.
|
![Design visualization of E St. interection with West Tunnel Portal](images/06pro8.jpg) |
The
same view of E Street, but with a DV showing West Tunnel Portal.
|
![Design Visualization showing the East Tunnel portal on E St](images/06pro9.jpg) |
This
DV shows the East Tunnel Portal on E Street.
|
Connecting
with the Layman
DV technology
not only helps engineers during their planning process, but also it
serves as an effective way to communicate clearly design implications
to non-engineers. Thanks to this technology, highway engineers now
are able to take their composite drawings to public meetings and present
them to non-engineers with ease.
Engineers
can show different alternatives for various types of bridges, alignments,
and other possibilities and provide decision-makers with a better
understanding of what the completed facility will look like before
they actually make a decision. This technology provides decision-makers
with better information to base their decisions on.
The layperson,
even when shown sophisticated 2-D engineering drawings, often has
difficulty conceptualizing what the constructed facility would look
like. Making decisions without fully grasping the design implications
often causes problems down the line. After construction work has started,
making changes is either impossible or very expensive.
Dan VanGilder
of FHWA's EFLHD Technical Services Branch witnessed an excellent
example of the impact of DV technology on decision-making during a
road project at Manassas Battlefield National Park in Manassas, VA.
The project involved lowering the grade of a section of a roadway
with
poor sight distance. Early in the development of the project, the
engineers explained to the local residents that the present road was
hazardous because motorists driving down the hill could not see traffic
stopped at the intersection.
Before
VanGilder's DV presentation, citizens in the area were not convinced
that the project was necessary. But then he showed a video simulation
of a vehicle driving down the hill as it currently was configured,
demonstrating that motorists could not see vehicles at the intersection.
After that, he showed a DV simulation with the grade lowered, which
demonstrated that this improvement would enable the driver to see
the intersection clearly. After the presentation, the viewers said
that they appreciated the safety concerns and acknowledged that the
project would benefit the local population. The DV demonstration thus
became a crucial factor in obtaining approval for the project, which
has since been completed successfully.
![Street condition near Union Station in DC](images/06exn5.jpg) |
Existing
street conditions are shown near Union Station in Washington,
DC.
|
Getting
the Best Solutions
Another
impact of DV is that decision-makers feel more comfortable allotting
the extra project funds needed for the more visually pleasing designs,
having seen the alternatives in life-like 3-D images. The DV presentations
also can be posted on the client organization's Web site, enabling
a broad audience to view them.
The technology
helps in pre-assessing the environmental impacts of new structures.
A section of a proposed mountain road, for example, may either be
supported by a bridge or by lower-cost earthworks encased by a retaining
wall on either side. Both alternatives can be demonstrated with a
PowerPoint® presentation, showing the different options,
environmental impacts, and cost associated with each option.
Similarly,
DV can be used for viewing the anticipated progress of the re-vegetation
of a construction area. Users can take existing trees and generate
a computer image of their progression to see what they will look like
in 5 or 10 years.
The DV
technology helps in evaluating the impact of roadway widening projects.
For one such project, the client wanted to see the impact the widening
would have on a historic stone house in Manassas Battlefield Park.
I examined a design that included shoulders and one with curbs. After
viewing the impacts of both designs, it was decided the best option
was to widen the road using the curbs.
DV
Techniques
A variety
of techniques are used in DV, including simple computer painting programs,
photomontage, video overlay, and 3-D animation. A computer paint program
enables the user to copy an image from a photograph of a completed
design onto an existing photo in order to create an image of a new
proposed design. Photomontage enables the user to place a view of
a 3-D computer model, rendered with photo-realistic materials, into
an existing photograph precisely at the proper location
and viewing angles, again creating an image of the proposed design.
Producing dramatic before-and-after photos is as simple as displaying
the existing photo and the DV photo.
Video
overlay merely extends the photomontage concept by placing a view
of a video image into an existing photograph. The result is a view
of the design with live action movement, which adds a heightened sense
of realism.
Finally,
3-D animation, also sometimes called "drive-through" or
"fly-through," is a powerful and flexible method for viewing
a design project in virtual reality. Computer software is used to
place "cameras" or views into the 3-D computer model. The
camera views can be static or allowed to move through the model. The
software also allows for the inclusion of other animated objects in
the computer model, such as automobiles, trains, and pedestrians.
The 3-D model uses photo-realistic materials, lighting effects, shadows,
and reflection. The camera views are scripted so that the resulting
images simulate a video taken from within the 3-D model. Music can
be added. The final animation is a truly dramatic presentation of
a project design.
Hardware
and Software Requirements
Still
photograph DV can be carried out using any modern desktop computer,
but video animation typically calls for more specialized high-end
workstations. The data for each picture frame need to be "crunched"
at high-speeds, such as 30 frames per second. A few years ago, we
had to let the computers process the information overnight to produce
an animated simulation. Now, thanks to the tremendous increases in
computing power, what used to take 12 hours takes only an hour.
My own
hardware consists of a Silicon Graphics visual workstation equipped
with duel Pentium III 550 megahertz Xeon processors, 1 gigabyte of
RAM, and two 18 GB hard drives. Also required are a tape drive (for
data backup), a professional desktop editor videocassette recorder,
a color video monitor, a CD duplicator, and a large-format color plotter.
Typical
software required is a suite of multimedia software like Photoshop,®
Premiere,® PageMaker,® and Illustrator®
software from Adobe® Systems. Also required are roadway
design software products like GEOPAK,® and Computer-Aided
Design and Drafting (CADD) such as MicroStation.®
For landscaping, to create different images of trees, for example,
I use Onyx Tree. TM To create animated images of people
and objects (e.g., trucks, signs), a software like ModelVisionTM
is useful. For making the final presentation to clients, software
such as Microsoft PowerPoint,® Corel®
Presentations,TM or Adobe Premiere® can
be used.
![Design visualization of same street near Union Station](images/06nor2.jpg) |
This
DV shows the same view, but with proposed improvements including
a concrete sidewalk and bike trail.
|
Other
Projects
I regularly
execute DV projects for the National Park Service, Forest Service,
the U.S. Department of Transportation, and other clients. I also have
done work for local jurisdiction bodies like the Washington, DC, city
government and local county governments, and also the Virginia Department
of Transportation.
Recently
FHWA's Eastern Federal Lands Highway Division carried out a simulation
for several congressmen, involving a proposed tunnel for a section
of E Street, which runs along the White House's south side. The congressmen
wanted to know the potential aesthetic impact of the tunnel (desired
for security reasons) on the surrounding architecture, including the
White House. I prepared a photomontage visualization, presenting the
congressmen with alternative views of the proposed structure.
Such
is one of the many examples of the DV's uses. The technology is fast
becoming an indispensable tool for highway construction organizations,
benefiting not only engineers but also non-technical officials and
the public. The technology is proving how the old adage that a picture
is worth a thousand words is still very true.
Richard
McDaniel is CADD/Design Visualization Coordinator for the Technical
Services Branch of FHWA's Eastern Federal Lands Highway Division (EFLHD).
During 13 years at EFLHD, he has received more than 30 FHWA Special
Act Awards for graphics and design visualization work. Examples include:
- Video
Production, National Building Museum Exhibit "Lying Lightly
on the Land"
- Design
Visualizations, George Washington Memorial Parkway Barrier Study
- Design
Visualizations, DC Department of Trails
- Interactive
CDs, National Forest Highway Network
- Interactive
CDs, DC Mall Roads Interagency Workshop
Other
Articles in this issue:
Arizona
Tackles Work Zone Delays
A Hallmark of Context-Sensitive Design
Safer Roads Thanks to ITS
Do Better Roads Mean More Jobs?
Exciting Opportunity for ITS Work
See It Before It's Built
Roadway Lighting Revisited
The Man Who Loved Roads
Benefitting
from LTPP—A State's Perspective