Department of Transportation

Overview

When conditions warrant, a design exception may be granted for a project design that proposes one or more controlling substandard design elements (CSDEs). A design exception may be approved when it can be documented that a lesser design value is the best practical alternative. The factors to be considered when determining if a lesser design value should be elected shall include social, economic and environmental impacts together with safe and efficient traffic operations.

Section Index
  • Section 1 - General
  • Section 2 - Controlling Design Elements
  • Section 3 - Design Standards and Relative Resources
  • Section 4 - Project Types Requiring a Design Exception
  • Section 5 -Projects Exempt from the Design Exception Procedure
  • Section 6 - Design Exception Report Format
  • Section 7 - Crash Analysis
  • Section 8 - Geometric Review (Concept Development Phase)
  • Attachment 1 - Cover Letter
  • Attachment 2 - List of Controlling Substandard Design Elements for Design Exception Type 1 (Design Speed = 50 Mph)
  • Attachment 3 - List of Controlling Substandard Design Elements for Design Exception Type 2 (Design Speed < 50 Mph)
  • Attachment 4 - List of Controlling Substandard Design Elements for Design Exception Type 3 (Major Access/Developer Projects; All Design Speeds)
  • Attachment 5 - Tables (Design Exception Type 1, 2, or 3 as appropriate)
  • Appendix A - Vertical Curve Conversion from SSD to V (Calc.) & Superelevation Safe Speed Calculation
  • Appendix B - Low Cost Safety Measures
  • Appendix C - Intersection and Link Crash Tables
  • Appendix D - Sample Design Exceptions

BDC announcement BDC19T-01 (August 21, 2019)

Design Exception Manual (pdf 871k)



Last updated date: January 3, 2020 11:22 AM