Alert services


Traveller information system can generate and disseminate alerts to travellers. Alerts consist of:

  • Minor delays to services
  • Major delays to individual services
  • Road closures and diversions
  • Route truncation or suspension
  • Current events and disruptions, especially if unexpected
  • Planned/known disruptions, including roadworks, diversions, events, demonstrations
  • Planned route or timetable changes
  • Communications from CAD/AVM dispatchers
  • Promotional messages from the transit authority/operator

Alert services and information can be clustered in three strands:

  • General alerts, intended for all users
  • Route- or location-specific alerts, to be channelled to specific groups of users
  • Personalised alerts, to be channelled to users that have requested the information, or who are identified as users of the impacted services. These can be constructed as ‘push’ or ‘pull’ services, on the preference of the user

Technologies, data and resources

Alert Services are software applications. They are embedded in or supplemental to the Traveller Information services or the CAD/AVM system. They utilise the Traveller Information communication channels, including PC/internet, mobile devices, in-vehicle display, and at-stop/at-station displays.

Alert services utilise data from the CAD/AVM system and the Traveller Information systems. This is supplemented by information from traffic and travel control centres, police and other authorities.

Advantages and Cautions

The primary advantages of Alert Services are to:

  • Provide travellers with relevant information before they travel and while they are in transit
  • Redistribute travel demand from routes/areas where the service is disrupted or degraded
  • Alert passengers to security threats and divert them from areas of danger
  • Exploit existing channels for cost-effective dissemination of important information

The principal cautions in relation to Alert Services are:

  • Messages should be tested against a wide audience range to ensure that content, phrasing and clarity meet the objectives

Relevant Case Studies