Minnesota Department of Transportation

511 Travel Info

Geometric Design



MnDOT's Geometric Design Support Unit helps develop preliminary plans consistent with MnDOT and AASHTO standards. We also research and develop geometric design standards, review and make recommendations regarding design exceptions, and coordinate statewide geometric design training programs.


Early concept layout review

We encourage your submittal of preliminary design concepts and layouts for comments prior to the final layout phase. This initial review can:

  • Increase the probability of an early quality product
  • Generate alternatives
  • Familiarize our unit with planning and design problems
  • Help the project manager evaluate solutions

Preliminary design is an iterative process and multi-disciplinary throughout the layout development process.

Layout preparation

Conceptual layouts are used to look at various alternatives before selection of a preferred alternative layout. The preferred alternative layout is completed to a higher degree of detail because it is used at public meetings, to evaluate design exceptions, and achieve staff approval. A staff approved layout is used as the basis for municipal consent and detail design.