This diagram is shown as four colored rectangles representing classes filled with smaller white rectangles representing subsystems:
- Travelers (yellow): remote traveler support and personal information access
- Centers (green): information service provider, traffic management, emissions management, emergency management, transit management, payment administration, fleet and freight management, commercial vehicle administration, archived data management, and maintenance and construction management
- Vehicles (blue): maintenance and construction vehicle, transit vehicle, commercial vehicle, emergency vehicle, and vehicle
- Field (orange): roadway, security monitoring, roadway payment, parking management, and commercial vehicle check.
They are all interconnected by straight lines representing communications links going through one of four pink ovals representing types of communications:
- Wide area wireless (mobile)
- Fixed-point to fixed-point