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Project Development

Deviation Guidelines

Deviations are stand-alone documents. There should be enough information and description of the project, the deviation and the justifications so that the approving authority can understand the whole story and have all the information necessary to approve the deviation. 

Project Overview

  • Project Description (type, purpose, major work items, etc). 
  • Highway classification
  • Design matrix
  • Funding sources

Existing Conditions

  • Location
  • Lane configuration
  • Posted speed and design speed
  • Present and 20 year projected ADT
  • Truck percent
  • Rural, urban or developing
  • Existing route development plan (if applicable).
  • Existing environmental issues (if applicable).
  • Existing Right of Way (if applicable). 
  • Existing horizontal alignment (if applicable).
  • Existing alignments (horizontal alignment, profile grade, super elevation diagram, etc., if applicable).

Deviation Description

  • Design standard that will be deviated
  • Dated reference in the Design Manual that established the standard
  • Station and/or milepost of the deviation
  • Previously approved deviations at same location

Alternatives

  • Description
  • B/C ratios
  • Advantages/disadvantages
  • Reasons for rejections
  • Cost estimate

Recommendation

Summarize the deviation and list the two required justifications the recommendation are based on.

Justification

The deviation must include these two explanations:

  1. Give reasons why design standard will not be met
  2. Provide support to justify the proposed design

    Accident history of potential
    Benefit/Cost analysis
    Cost to build to standards
    Cultural impacts
    Engineering judgement
    Environmental issues
    Existing conditions
    Geotechnical feasibility
    Guidelines from AASHTO, MUTCD, Local Agency Guidelines (LAG), FHWA publications and other recognized technical sources
    Insufficient Right-of-Way
    Memos from specialists (Traffic, Hydraulics, Materials, etc.) concurring with proposed design)
    Predictions from ROADSIDE Safety program
    Relationship to future improvements
    Route Continuity
    Truck Turning Diagrams
    Deviations must be supported by at least two of these (Design Manual 300.04(5))

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Mitigation

Summarize the deviation mitigation options used to mitigate the deviation to an improved condition but still not providing for Design Manual standards. For additional information see:

Attachments

  • Vicinity map
  • Plan sheets
  • Photos
  • Charts – use to compare options, design elements, costs, etc.
  • Design Manual Figure or Section that shows Design Standard

Deviation requests should be submitted as early as possible in the design process. They should be submitted as a separate document before the Design Documentation Package is submitted. The approved deviation is to be included in the design documentation package.

For deviation examples, see Design Deviation Examples on the Project Development website.