OneBusAway has become a useful tool to many transit riders but recently the arrival predictions have become more erratic and unreliable since Metro’s program to equip its bus fleet with GPS began. Eastside buses like the 255 have been giving wild estimates like 100+ minute delays or fluctuating between schedule data only and real-time data. And there was a case where the next Route 26 bus was predicted to be over five hours away. Incorrect information is worse than no information since repeated mistakes eventually undermine people’s confidence in real-time information. At the very least it is good for nothing; at the worst it could mislead and create trouble for those who trust it. OneBusAway is only as good as the data provided by the transit agencies.
The problem with King County Metro’s real-time data is a complex one. It involves the combination of two vehicle location systems (the old odometer based system and the new GPS based system) and the translation of data from those systems into a format that OneBusAway understands. I asked OneBusAway’s S. Morris Rose whether the problems would go away once all of Metro’s buses are fitted with GPS. Rose told me that they now think the problem is related to the GPS-equipped buses. Rather than wait for the GPS transition to be completed, work is underway to address the problem with meetings between OneBusAway and Metro engineers. Given their limited resources, I hope that is a sign that Metro is taking data accuracy seriously; if not they really must, because customer trust is hard to win back once it is broken.