Design Resources

Resources and References

AASHTO Green Book

NACTO Urban Street Design Guide

FHWA policies and FAQs

Other practical tips for accessing more detailed information

Myth vs. Fact

Explore common misconceptions about Federal design requirements. This page clarifies facts to empower transportation professionals and agencies to embrace design flexibility, foster innovation, and make informed decisions. By separating myths from facts, this page provides the clarity needed to navigate Federal guidelines.

Myth: The local agency must follow the AASHTO Green Book.
Fact: Agencies can use various design guidelines, including NACTO.

Myth: FHWA requires a minimum Level of Service (LOS) C.
Fact: FHWA does not mandate specific LOS values for projects.

Myth: FHWA requires a 20-year design period for all roadway projects.
Fact: This applies only to Interstate projects.

Share Your Myths

Have a misconception you’d like clarified? Contribute your questions here to help us grow this resource.