California Department of Transportation

Module 3: Visual Quality and Visual Impacts
Lesson 15: Documentation

Slide 68

Module 3 Part C Welcome

Welcome back to Visual Impact Assessment Training.  This section contains Part C of Module 3 of the Visual Impact Assessment training program produced by the California Department of Transportation (Caltrans) with the support of the University of California at Davis (UC Davis) for the training of selected employees of Caltrans. It is now available on-line to anyone interested in how Caltrans conducts visual impact assessments.

 The presentation you are about to view is the third part of the third module. It is the final presentation in a series of six presentations. There are five presentations which precede this final one.  If you have inadvertently started with this presentation, you may wish to review these other presentations before beginning Part C of Module 3.

 In Part A of Module 3, you learned how to define the visual quality as a product of vividness, intactness, and unity.  You also evaluated, as part of the Team Project, the existing visual quality of one of the alternatives.  In Part B we examined visual impacts, how to assess visual impacts, and how to provide mitigation.


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We are going to examine the VIA related documents in this lesson; how the accuracy of the VIA is assured, and some suggestions for particular language that should be avoided.  We will also look at the use of simulations in documents.


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Recall that there are two documents that are being created as part of communicating the visual impact assessment.  First, of course, is the VIA itself.  The second is the Environmental Summary—the text by which the VIA is reported in the project’s environmental documents.  The VIA is authored by the landscape architect and reviewed by the environmental generalist.  The roles are reversed for the Environmental Summary.


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Quality Assurance

The landscape architect reviews the summary in the environmental document, if the VIA and summary are consistent the landscape architect signs the Internal Certifications Form.  If the two documents are not consistent with each other, then the landscape architect and the environmental generalist will need to discuss and resolve any discrepancies between the VIA and the Environmental Summary.


Slide 73


There are some words and phrases that the Landscape Architect should avoid using in the VIA.  The landscape architect should check with the project’s environmental generalist to become familiar with which words to avoid using in the VIA.  Different districts avoid the use of certain words that may be acceptable in other districts.   Review the slide for a list of words that should be avoided.

One of the primary reasons for conducting this training is to assure the consistent use of words and terms. Consistency should always occur in the document.  It should also be consistent from project to project within a district.  Ideally, the language that is used to assess visual impacts would be consistent across all of Caltrans.


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Guidance for what language is appropriate to use in a VIA can be found from several sources including a review of those visual impact assessments that are considered well done.  Chapter 27 of the Standard Environmental Reference (SER) also has advice on what language is appropriate to use in a VIA.  Caltrans has many experts (both in the districts and in headquarters), especially the environmental generalist, who can assist a landscape architect in selecting those words that convey the right meaning without inadvertently conveying an unintended meaning.


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Simulations, also known as visualizations, are useful tools for communicating changes in the visual environment.  There are many types and many uses for simulations, as listed on this slide.

Simulations are images of a future condition.  They are helpful in conveying what will be changed and what will not be changed by a proposed highway project.  The techniques and tools to create simulations have certainly changed or become more broad but essentially there are only a few ways of illustrating changes—either as a two-dimensional image, a three-dimensional image, or a four-dimensional image.  Today most simulations are done using computers but illustrative drawings—from cross-sections and elevations to rendered perspectives—are still useful in certain situations.

Not only is there a range of types but these types can be used for different purposes—from early conceptual studies to construction documents.  The appropriate type of simulation must be employed for a particular use.

This is not a course on simulations, however.  Nonetheless let’s examine several examples merely as an overview of the range of simulations used in visual impact assessments. 


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There are essentially two reasons for creating a simulation of a new highway—either to portray the experience of the new highway or to provide information about the appearance of the new highway.  The purpose of the simulation will determine how it is constructed.  Be sure to understand the needs of the audience before selecting the type of simulation to produce.


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Let’s go over a range of simulations—a set of examples that display increasing dimensions (from 2 to 3 or even, 4 dimensions), increasing complexity (both in terms of the project and the construction of the simulation), and increasing realism.  The escalation of these types of simulations requires an increase in the use of specialized tools and training, an increase in production time, and an increase in costs. 

Be sure to pick the level and type of simulation that is appropriate to portray the project and its potential impacts.  Using a very sophisticated simulation when a simpler version would have sufficed is a poor use of resources and frequently makes an audience believe that they are trying to be “snowed.”   Similarly, using simple simulations for complex or controversial projects may have an audience wondering if Caltrans is actually concerned about visual issues.


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The simplest simulations are cross-sections or elevations.  These can be hand-drawn or computer generated.  They tend to be diagrammatic with the vertical axis exaggerated.


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An illustrative perspective can also be hand-drawn or computer generated.  Recently computer programs are becoming more and more like simple hand sketching—allowing comparison of design alternatives early in the VIA process.  Point of view is an important consideration.  A “realistic” simulation isn’t always necessary.  Professional judgment about what needs to be communicated is critical in deciding point of view.


Slide 80


Photoshop changed the way we could interpret the world and quickly became the standard simulation technique replacing photo-retouching by artists.  Simple two-dimensional photo-realism simulations generated on computers is the work-horse of the industry.


Slide 81


Paintings and drawings of the proposed project are a traditional way to communicate what something will look like in the future.  The computer takes this a step further, creating accurately scaled images. Computers allow a designer to generate a series of quick studies at relatively low cost per image, allowing more design exploration and flexibility. 


Slide 82


Adding three dimensional models to photographs is the next level of simulation.  A 3-D model is generated separately, usually from project plans, adjusted to the calculated point of view of the photographer.  The model and the photograph are then merged and the model “painted” to look realistic.  The following slides illustrate how this process was used on a recent Caltrans project.


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Step 1—Scan or import existing site photo into computer


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Step 2—Build or import a 3-D computer model of existing site and proposed design


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Step 3—Match view of 3-D computer model to existing photo


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Step 4—Render 3-D model into photo


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Step 5A—Add short wall to top of earthen berm to begin rendering Alternative A


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Step 5A—Add realistic textures and vegetation to berm with short wall to complete the rendering of Alternative A .


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Step 5B—Add long wall to top of berm to begin rendering Alternative B


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Step 5B—Add realistic textures and vegetation to berm with long wall to complete the rendering of Alternative B


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Simulations, even elementary ones, require a calibrated eye in order to create an accurate image.  Accuracy is more than placing the right objects in the right location—it requires that the image capture the experience someone would have in the project area.  Maturity of the vegetation and the aging of various introduced materials are crucial to creating a realistic impression.  The inclusion of non-project elements needs to be decided.  If a particular view of a project is actually hidden by non-project elements and will never be seen from that particular angle, it may be best not to select that view for simulation.   Similarly, the choice of the original image, how much of the context is cropped, is critical to communicating the changes the project will have on the corridor and its context.  How much intervening vegetation or development should you incorporate?  How do you add undefined mitigation or other project or aesthetic features.  Then there are practical considerations, how is the image going to be used, what should be the format, the file size?

There are no hard and fast rules here.  One needs to use professional judgment but be very careful that you are not trying to “sell” the project with an image that in fact few people will actually see.  Simulations are best when they are used as a design tool to evaluate alternatives.  They are no substitute for numerical ratings or a descriptive narrative of visual impacts—they augment the assessment, never replacing it.


Slide 92


If you have questions about this on-line presentation, please talk first to people in your office who may have taken the course in a class-room setting.  You may also contact your District Coordinators from either the Landscape Architecture Program or the Environmental Program for assistance.


Module 3C, Lesson 16 - Conclusion