KEY POINTS:
Could you please find out just how the electronic signs at bus stops actually work.
I like to catch a bus which drops me off near work but only comes every half hour. There are other more frequent but less convenient buses I could catch. The other day the countdown to my bus' arrival occurred, then the 'due' sign flashed up, followed three to four minutes later by 'delayed', which seems to be a euphemism for 'not coming'. In the meantime I had let three of the alternative buses go by and had another 15 minutes to wait.
Are the signs programmed to display the advertised bus timetable, or do they have a link to the bus? Why then the charade of a countdown and a due sign when the bus actually isn't going to turn up? I'm a loyal bus user but this tries my patience.
Kim Hastwell, Mt Albert.
Auckland City Council introduced the system in 2003. The Auckland Regional Transport Authority (ARTA) has been responsible for it since 2006.
Here's how it works. Buses are fitted with onboard global positioning system (GPS) equipment so they can be tracked on the bus route.
At the start of each trip, the driver keys in the route number and departure time into the ticketing machine. As the bus travels along its route, predicted arrival times are sent to the electronic display boards at the bus stops. This information is relayed along the route as the bus passes set points, using information from the GPS.
'Due' means the bus is expected to arrive within two minutes. If the system can't find a service it knows should be starting, it displays the scheduled arrival time on the screens until the driver logs the service in. If after 10 minutes the service is still not logged, it shows as DLY (delay).
ARTA is currently working with bus operators to reduce DLY signs by fixing faults in equipment as soon as they are reported, and by putting screens in all the buses so that the driver can see if they've logged in successfully or not. The screen will show the driver their time against the service schedule.
Link buses also have the capability of announcing next-stop information through onboard speakers.
On some Link services, drivers may be told to take short cuts, because of traffic conditions or bunching of buses. By taking short cuts, however, the arrival time may suddenly disappear from the electronic sign board - gone off the radar, as it were.
As well, there is a GPS-based signal pre-emption process that lets bus drivers communicate their position to the city's traffic signals system. If a bus approaches an intersection with signal pre-emption, the system can request traffic signal priority for the bus.
For example, if the lights are green but about to turn red, the green phase can be extended by up to 10 seconds so that the bus can keep up with its schedule. If the lights are red, the green phase can be brought forward by 10 seconds.
