AASHTO design criteria, as presented in the 1990 "Policy on Geometric Design of Highways and Streets" will govern on this class of highways.

2.2 Special Design Guidelines    (Back to top of page)  

These Special Design Guidelines are presented to assist the designer in avoiding, minimizing, or mitigating negative impacts upon the environment and other sensitive resources as well as to enhance the design to fit the context of the project site. These Special Design Guidelines note the importance of the individual resources and suggest tools which may be used in the development of a design which recognizes the resource at the proper level of importance. Under this Functional Classification there are guidelines for:

> Scenic Resources

> Village or City Entrance Considerations

> Economic Vitality Considerations

When such resources are present within a project site and the use of the tools suggested do not provide an adequate protection of the resources then the design may be eligible for reductions in geometric values. The decision to pursue reductions in the standards is subject to approval in accordance with the "VAOT Design Exception Policy".

The primary strategy for Freeway projects should be to use alternative roadway alignments to avoid an impact to the resource. Reduction in the size/area of impact, and the utilization of creative design and engineering solutions should be pursued. In certain cases, special design features to enhance the design's integration into the environment are encouraged. These strategies are all described as "common tools" in the following subsection.

2.2.1 Common Tools for Freeways   (Back to top of page)  

> Alterations to typical cross section including:

$ Sideslopes steeper than normal (in combination with additional guardrail)

$ Use of curb and closed drainage systems (elimination of roadside ditching)

$ Retaining walls

> Wetland and wetland buffer restoration/creation

> Wildlife habitat restoration/creation

> Water quality/stream bank, stream buffer, lake buffer creation, restoration, and enhancement

> On and Off - site mitigation

> View/scenic enhancement through vegetation management

> Use of guardrail to allow preservation of significant features including native and planted vegetation

> Use of grade separation/bridging/elevated structures etc.

> Fencing or Landscaping for screening or earth berm buffers.

> Retrofitting of historical bridges for alternative uses off-the-freeway.

> Integration of historical features in interpretive facilities, rest areas, overlooks, etc.

> Rest area and truck weighing areas facility design may need special consideration.

> Architectural/Landscape design:

2.2.2 Historic/Archaeological Considerations  (Back to top of page)  

Freeway construction projects should be designed to avoid historic or archaeological resources wherever possible. This may be in the form of avoiding disturbance of specific sites and structures, historic districts, or areas where the presence of the road conflicts with a historic land use pattern. Where avoidance proves unfeasible, every effort should be made to minimize impacts including mitigation strategies and design enhancements.

2.2.3 Natural Resources  (Back to top of page)  

Freeway construction projects should be designed to avoid natural resources wherever possible. This may be in the form of avoiding disturbance of specific sites or areas where the presence of the road conflicts with important natural resources. Where avoidance proves unfeasible, every effort should be made to minimize impacts or pursue mitigation strategies and design enhancements to enable the maximum integration of the Freeway with the resource.

All Freeway projects must consider the presence of environmental resources in project planning, design and construction. The following resources are protected by State and Federal law:

> Water supplies

> Groundwater protection areas

> Watershed protection areas

> State and Federal forests and wildlife management areas

2.2.4 Recreational Resources   (Back to top of page)  

Proposed Freeway construction projects should be designed to avoid public recreational facilities wherever possible. Where avoidance proves unfeasible, every effort should be made to minimize impacts including mitigation strategies and design enhancements to enable the maximum integration of the Freeway with the resource. Examples of Recreational Resources are:

2.2.5 Scenic Roads or Views Considerations  (Back to top of page)  

All Freeway projects should consider scenic and aesthetic issues for projects that possess scenic qualities. Assessment of scenic qualities should be completed in the Project Development Process. This includes, but is not limited to, "Designated Scenic Roads" or "Scenic Byways" as well as other roads with scenic attributes. Techniques for preservation of scenic resources should be employed for both scenic resources seen from the road, as well as views of the road from surrounding areas. The following techniques, in addition to the tools listed above, should be considered where scenic issues are identified in a Freeway project:

> Scenic turnouts should be considered and provided, where demand is apparent.

> Treatment of bridges, abutments, and retaining walls should de-emphasize structures where prominent long views and vistas are present.

2.2.6 Village or City Entrance Considerations   (Back to top of page)  

Because Freeways in Vermont do not generally "enter" or pass directly through villages or cities in the usual sense, this issue arises primarily at interchanges where freeway ramps meet other roads in or leading to town centers and other developed areas. The following additional guidelines are appropriate at such locations:

2.2.7 Economic Vitality Considerations  (Back to top of page)  

Creative design should integrate economic issues where the transportation of goods and services is of significant importance. On those routes within economically important corridors, the following additional guidelines may be appropriate:

> Use appropriate turning radii for large commercial vehicles

> Use appropriate ramp widths for large commercial vehicles

> Consider rest area facilities or breakdown facilities for trucks

> Consider park and ride facilities at interchanges

> Consider interchanges with other travel modes (air, rail, etc.)

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