| Source Element | Destination Element | Flow |
|---|
| Missouri DOT – Tunnel Control Center (Lindbergh Blvd) | Private Vehicle | emergency acknowledge |
|---|
| Private Vehicle | emergency data request |
| Personal Computer | St Louis Metropolitan Police Center | emergency notification |
|---|
| Private Vehicle | Missouri DOT – Tunnel Control Center (Lindbergh Blvd) | emergency notification |
|---|
| St Louis Metropolitan Police Center | emergency notification |
| St Louis Metropolitan Police Center | Personal Computer | emergency acknowledge |
|---|
| Private Vehicle | emergency acknowledge |
| Private Vehicle | emergency data request |