"Functions" are a description of WHAT the system
has to do. In the National ITS Architecture, functions are defined
at several different levels, ranging from general subsystem descriptions
through somewhat more specific equipment package descriptions to Process
Specifications that include substantial detail. The equipment
packages or "functional areas" that are associated with one or more elements in the
California Statewide ITS
architecture are listed below. Each functional area is a link to more
detailed information, including the portion of the California Statewide
ITS Architecture that implements the function, and the more detailed
functional requirements that are applicable.