City
Seattle Transit Blog: What's Up With OneBusAway
Over on Seattle Transit Blog, King County DOT's IT Service Delivery Manager, Wayne Watanabe, and Washington State Transportation Center director Mark Hallenbeck have written a lengthy post attempting to explain some of the problems with OneBusAway, the app that provides real-time bus arrival information.
As users of OneBusAway are well aware, the app has recently been plagued by a series of bizarre problems, including arrival times that are hundreds of minutes in the future or appear to be running dramatically early, buses that don't show up at all, and buses that arrive but don't show up on the list.
The first thing that happened, Watanabe and Hallenbeck note, is that OBA creator Brian Ferris left the UW, leaving Metro and the university to cobble together a partnership to keep the app running.
At the same time, Metro started switching its bus tracker over to a GPS-based, on-board model, with the goal of providing more reliable real-time information; until the entire system is GPS-based, Metro has to coordinate OBA with two separate tracking systems, which can lead to errors. (As those who tried to use OBA during recent snowstorms or to track tunnel buses know, the current tracking system, which uses stationary tracking devices mounted to signposts, doesn't work underground and isn't reliable during major weather events.)
Meanwhile, as if that wasn't all enough, Metro went through a massive service change (another systemwide service update is due in September), creating "large, multiple data updates."
In the meantime, though, OneBusAway users may have to accept that the formerly miraculous app is a little less reliable.
As users of OneBusAway are well aware, the app has recently been plagued by a series of bizarre problems, including arrival times that are hundreds of minutes in the future or appear to be running dramatically early, buses that don't show up at all, and buses that arrive but don't show up on the list.
The first thing that happened, Watanabe and Hallenbeck note, is that OBA creator Brian Ferris left the UW, leaving Metro and the university to cobble together a partnership to keep the app running.
At the same time, Metro started switching its bus tracker over to a GPS-based, on-board model, with the goal of providing more reliable real-time information; until the entire system is GPS-based, Metro has to coordinate OBA with two separate tracking systems, which can lead to errors. (As those who tried to use OBA during recent snowstorms or to track tunnel buses know, the current tracking system, which uses stationary tracking devices mounted to signposts, doesn't work underground and isn't reliable during major weather events.)
Meanwhile, as if that wasn't all enough, Metro went through a massive service change (another systemwide service update is due in September), creating "large, multiple data updates."
Take a step back and look at all the factors. It’s not the same, but think about what happens when you try to digitize your dad’s (or grandpa’s) Led Zeppelin album to play on your iPhone. When you convert a classic vinyl LP into a digital format, it’s no good without noise correction. It can be a tricky balance that you can’t correct until you actually listen to all the songs. Leave in all the clicks and pops, and the static is louder than the music. If you eliminate too much, you weaken the integrity of the analog signal. And, if you are too brutal with the noise reduction, you can lose the signal entirely.
Right now, OBA is catching all the clicks and pops in Metro’s data streams and reporting them as information about buses on the road. With more data streaming in from Metro’s new OBS, there is “noise” we never expected – and now we are trying to track it, filter it, and improve the accuracy of tracking information for public use. We assure you that everyone involved is very serious about finding solutions to fix the problems.
In the meantime, though, OneBusAway users may have to accept that the formerly miraculous app is a little less reliable.
