Computer Aided Dispatch (CAD) is a method of dispatching transit vehicles assisted by computer. The CAD feature gives the operator a quick awareness of what is happening on the street and the ability to take timely action to avoid service disruptions. In addition, CAD systems provide scheduling, assignment and event information. It allows dispatchers to quickly look up driver schedules, send text messages to drivers, and track the roadworthy status of every vehicle. CAD system electronically tracks and stores events ranging from schedule and route deviations, to excessive speeding or idling, accidents and driver emergencies.
The AVL systems installed in the vehicle sends the location of the vehicle and the vehicle is displayed on the computer. Some CAD systems fully utilize the capabilities of AVL systems. In these systems, in addition to the services provided by normal CAD systems, they also report the difficulties in making turns by the vehicles.
Disruption Identification and Restoration of Service
All the data generated by CAD/AVL systems are huge and consumes lot of dispatchers’ time to manage real-time bus operations. Transit Operations Decision Support Systems (TODSS) developed a tool to support dispatchers during real-time transit operations in response to incidents, special events, adverse weather conditions, etc. AVL systems text messages, schedule adherence messages, system health messages, and mechanical alarms are examples of event message types used as sources of information for incident notification purposes. The identification of service disruptions is based upon the set of rules that takes into consideration the time of day, service level, and service (e.g. weekday, Saturday, Sunday) applied to the sources of information. Service levels such as Arterial, Feeder, Express, Circulator, or Planned Special will dictate their unique threshold settings.
AVL systems sends text messages to the Service Disruption Identification decision engine and once the message is analyzed and associated with a known operational scenario, the appropriate strategy is selected from the rules based responses. Both the disruption and the response are sent to the TODSS user interface. The user interface includes an area for manual entering of external sources of information directly into TODSS based on information such as severe weather conditions or traffic congestion. The bottom of the user interface contains links to references, CAD functions, and other information sources that are automatically setup for dispatchers to trace the status and impacts of the disruption notification.
The successful implementation of these systems improves service performance and real time operations.
Many public transportation trips require multiple transfers which may be between different modes, such as buses, subways, and commuter rails, and are often across multiple agencies. Any segments of a trip can be delayed and passengers wishing to transfer may miss their connection. Travelers are often uncertain about whether they will actually miss the planned connection due to lack of information and means of spontaneous communications. The proposed application will allow travelers to initiate a connection protection request using personal mobile devices, or through drivers using onboard mobile devices, and receive a confirmation based on a set of criteria, indicating whether the request is accepted. Travelers attempting to submit a request may be en-route (moving). The connection protection system improves the reliability of the transit agency.
Flexible Transport Services
Public transportation services have traditionally been designed to serve concentrated travel patterns that allow for large numbers of people to be conveyed along established routes following set schedules. Flexible Transport Services (FTS) can be categorized based on route deviation, point deviation, demand-responsive connector, request stops, flexible-route segments, zone route, etc.
Transit agencies operate FTS based on the request of the passengers. The passengers can inform the bus operator while boarding the vehicle of their final destination. The bus operator takes a route to deliver the passenger to their final location. However some transit agencies operate the bus on the fixed routes but deviates the path to serve the demand responsive requests of the passengers.
Operational issues connected to flexible services include allocating schedule time between fixed-schedule and demand-responsive operation, reservations, scheduling, and dispatch for demand-responsive operation, contracting, driver selection and training, and vehicle selection.
Transit agencies operate flexible services to provide cost-effective coverage to spread-out, low density areas, serve low-demand time periods, balance customer access and routing effectiveness, reduce or eliminate the expense of separate paratransit for people with disabilities, lay the groundwork for future fixed route transit and respond to community preferences and geography.