Phantom Buses

We have all suffered frustrations waiting at a bus stop for a bus that the Countdown screen or our phone app says is due in three minutes, but takes much longer than that to arrive. We can usually put that down to traffic congestion, road works, etc.

But over the past few months, many of us have had the welcome experience of our bus suddenly arriving unannounced. It sets you up for the day. But how does the Countdown system lose TfL’s buses?

The system uses GPS, transponders and gyros to pinpoint the location of buses and the direction of travel. The location data is sent to a central control centre, where it is analysed alongside historical journey time data to predict arrival times. The system is continuously updated, which explains why we see arrival times slip forward and back sometimes.

But some people have noticed recently that a few buses are showing the wrong time on their internal screens. Somehow, they have not been updated to show that summer has arrived. They are still showing GMT rather than British Summer Time, which the rest of us have been using since 30 March. TfL have suggested that this may be behind the phantom bus phenomenon, though it’s not clear how and why this should be.

We trust that the problem will be solved before 26 October, when good old GMT comes back to darken our lives for the winter. Or will all the buses then be arriving an hour early?