| Source Element | Destination Element | Flow |
|---|---|---|
| Arterial Roadside Equipment | Arterial Traffic Control Systems | signal control status |
| Arterial Traffic Control Systems | Arterial Roadside Equipment | signal control data |
| Caltrans Regional TMCs | Caltrans TMC Roadside Equipment | signal control data |
| Caltrans TMC Roadside Equipment | Caltrans Regional TMCs | signal control status |