Disruptions can have various causes and effects. Generally, disruptions to a single service should be communicated via your real time (SIRI-SM) system.
| Accident | |
| Bus issue | |
| Congestion | Unexpected traffic or an increase in traffic where a timetable has not yet been updated |
| Construction | |
| Demonstration | Protestors (rather than a system demo) |
| Event | |
| Holiday | |
| Level crossing failure | |
| Maintenance | |
| Medical emergency | |
| Other cause | |
| Police activity | |
| Roadworks | |
| Road blocked | |
| Road closure | |
| Strike | |
| Technical problem | |
| Traffic light failure | |
| Unknown cause | |
| Vandalism | |
| Weather | |
Effect
| Additional service | |
| Diversion | |
| Modified service | |
| No service | A service is not running for a period. Passengers should use a different service. |
| Other effect | |
| Reduced service | Some journeys are not running or do not run their full length. Passengers should wait for a later journey or use a different service. |
| Significant delays | 1 or more journeys are delayed a significant amount. Insignificant delays should be reported by a real time (SIRI-SM) system |
| Stop moved | |
| Stop not in use | |
| Unknown effect | |
