Guidance on the Use of the Metric and U.S. Customary Systems of Measurement
Metric System to U.S. Customary System Transition
In 1993, the Department adopted the International System of Units (SI; a.k.a. the Metric System) as our preferred system of weights and measures to comply with federal law. The law has subsequently been changed making the use of the Metric System optional. A decision document was approved on August 20, 2004 committing the Department to readopting the U.S. Customary (English) system of units and measures as our preferred system. Please refer to the Decision Document and the August 20, 2004 Transmittal Memorandum for information regarding the Departments' decision.
The Department has developed the Metric to U.S. Customary System Transition Plan for reverting back to the U.S. Customary system of units and measures. If the Transition Plan does not answer your questions, please refer to the Frequently Asked Questions (FAQ)for additional information. The Metric to U.S. Customary English Transition Team is being led by the Office of State Geometric Design Standards; Kevin Herritt is the Team Leader and Project Manager and can be reached at the following email address: kevin.herritt@dot.ca.gov.
- Transition Plan
- Metric to U.S. Customary System FAQ
- Project-related Guidance for Use During the Transition
- Transmittal Memorandum Announcing Website
The Department has released the 2006 Standard Plans, Specifications and Special Provisions in U.S. Customary (English) units in accordance with the Transition Plan. Projects on the State Highway System may now be developed, advertised, and ararded in English Units. A formal declaration of the units of measure that will be used must be made for all projects not yet awarded.
Metric Program
The Caltrans Metric Program, no longer in effect, was managed by the Chief of the Office of State Geometric Design Standards. Caltrans Metric Program, Guidance documents related to the Metric standards, and their application, are provided in the Metric to English Transisiont/Metric Program Memorandum and Letters for historical information purposes only.
Metric to English Transition/Metric Program Memorandums and letters
This page last updated July 21, 2006