Operations Control Center
The operations control center represents the operational center of the transport service where AVLS software is used to manage inputs from the AVLS system, the schedule system, bus-stop database and radio system for general operational control, including vehicle dispatch and dynamic rescheduling. Information retrieved by the control centre from the on-board AVLS can be passed on to update real-time passenger information services.
In the most common control center structures operations are divided amongst a number of controllers, each with responsibility for dispatch to routes in a particular area of the network. Control can be divided on an area level or route level, although in the instance of cross network services, route level control allows individual operators to maintain control when the route enters another area of the network. In the Dublin system priority is given to ensuring that buses depart on-time and then to maintaining the schedule.
The visual displays used by controllers can show a variety of service information. Generally the display includes the status of routes in a colour coded format for the easy identification of problems, individual routes with all stops, the direction of vehicle movement and vehicle position relative to the schedule. The display can also identify individual drivers and track specific routes.
In operational terms data exchange between vehicles and the control centre is done in a number of ways. Software updates and general route information are usually transferred to the vehicle’s on-board computer through a wireless local area network (LAN) at the bus depot or station, and this is usually done in packets as and when the network is available. Updates of vehicle route status from the GPS card embedded in the on-board computer are then sent to the control centre approximately every 20 to 60 seconds via GSM (global system for mobile communications) or dedicated wireless network. This location data can then be used to update real-time information services on the internet, on mobile devices, or at stops/terminals. Stop/terminals can also be directly updated from the vehicle itself. When other on-board ITS systems are also used, either integrated with the on-board computer or as stand-alone devices, wireless LAN can also be used to retrieve data from these systems. These systems may include electronic fare boxes, automatic passenger counter, driving-style monitoring systems or vehicle technical status monitoring systems. This information can then be used as required by the control centre, maintenance department, revenue department or any other section of the operation.
The control center is responsible for operations management in terms of computer aided dispatch, schedule adherence support, service compliance, dynamic rescheduling and potentially for driving standards compliance and route condition monitoring. It can also be used as service support for drivers and for demand responsive transport.
Advantages and cautions
AVLS control centers maximise service efficiency, asset utilisation and customer services through the continuous monitoring of the transport system. Continuous monitoring allows operators to react quickly to unexpected disruptions so that customer inconvenience is minimised. The main area to be cautious of relates to the means of information transfer, particularly in relation to real-time data transfer from vehicles to the control center and vice versa. Different communications systems vary in terms of cost, degree of reliability, or the quantity of information they are capable of transferring, these are key considerations in the choice of which is most suitable and will be discussed in further detail in the communications section.
Relevant case studies