No time to get bored at bus stops

The public transport authority for the Bizkaian capital of Bilbao and the surrounding area is intent on keeping the service efficient and reliable. To aid them in the task it has commissioned the Etra Norte company to incorporate a GPS (Global Positioning System) into the Bizkaibus fleet of buses. In this way, they can monitor the situation of each vehicle continuously and, at any time, know the exact time it will arrive at a bus stop. Moreover, the application of the system allows changes in the scheduled route to be made. if the situation requires, keeping the travelling public always informed, of course.

The Global Positioning System is based on the reception of signals from a number of satellites with the aim of fixing the exact position of an object, a bus in this case. It involves a sophisticated system of orientation and navigation, receiving and processing the information transmitted from a constellation of 24 satellites in position at an altitude of some 20,000 kilometres above the earth’s surface.

The buses have a GPS receiver on board. If the bus is travelling on a route that is located by three of these satellites, then their signals are received by the receiver, these signals are processed and the position of the bus is automatically determined. The problem arises when the vehicle cannot be “seen” directly by the satellites (for example, in tunnels or very narrow urban streets). The coverage of the GPS system on urban routes is between 50% and 60%. This situation has put the onus on the transport authority managers to take further measures to keep the position of all their vehicles constantly monitored.

Location of the bus
There are three factors involved in locating the exact position of the bus. In the first place we have the GPS positioning system as outlined above, secondly the vehicle wheel revolution count and thirdly, the bus the door opening mechanism as a confirmation of its position. This last factor operates in such a way that, when the doors open, the on-board computer checks the distance travelled and compares it with the distance that it theoretically, according to the schedule, should have travelled.

Thus, the information offered by these three factors is received at a central control and, once processed, is shown on the electronic map. All displays are refreshed every 20 seconds with the Central Control computers continuously receiving information from the buses on their position. Such information allows route changes to be made in any emergency situation. Moreover, communicating such information to the driver by radio or written message, also means passengers can be kept up-dated.

Keeping the travelling public informed
At the main bus stops in the transport system information panels for the public can be seen. By means of these display panels the service customer has information in real time, the time for the next bus to arrive. Also, over the next year, the transport authorities will be sending SMS messages on en-route incidents to those users who ask for such information and will be offering the possibility of consulting vehicle positions on Interne

Contact :
Iñaki Lombardía
Bizkaiko Foru Aldundia
inaki.lombardia@bizkaia.net
(+34) 944068574