California Department of Transportation

Compatibility Specifications for Automatic Vehicle Identification Equipment (Title 21) Support

Caltrans is mandated by State Administrative law to develop and maintain a specification that enables interoperability between all Electronic Toll Collection (ETC) agencies in the State. The Office provides resources to maintain a data registry for unique data assignments, and respond to technical inquiries about the specification and its implementation in system design.


Process to change the Title 21 Specification:

National Survey of other Title 21 Users: