Thursday, December 28, 2006

tracking the Ride with AATA

Homeless Dave tipped us off to the new goings on over at AATA. They have released a way to track the buses from the AATA website. You choose a route and AATA tells you the most recent timepoint, the status (behind or ahead of schedule), and the next timpoint, for both ingoing and outgoing buses.

After trying it out, our immediate reaction was, "Awesome! We're half way to a useful tool for bu riders." We saw two improvements that would make this great tool a whole lot greater: RSS feeds and mobile phone interface, and displaying the time the bus will arrive at my stop instead of the arcane timepoint-status-timepoint format. So we wrote to AATA and told them so via the comments/suggestion link.

Bobbie MacDonald, IT Manager at AATA, offered a speedy and helpful response to both queries. As for the RSS and mobile interface, she says, "we do have plans for PDA and cell phone interface, but all this takes money and right now it's tight."

The second issue requires a little journey into the guts of transit scheduling. First of all, it is really difficult to accurately predict future arrival times based on the current location of a bus. And the further out you try to predict, the worse it gets. It is much easier to mark a few spots along the route with expected arrival times and report whether the bus was ahead or behind schedule at that point. AATA calls these timepoints and uses them to measure schedule adherence on a route. A timepoint isn't the same as a bus stop. Timepoints may be bus stops, but not all bus stops are timepoints. As McDonald explains,

"We do not guarantee that we will be at all stops at a certain time, just timepoints as listed in the ride guide. Therefore, what we are displaying is the last timpoint the bus passed, what the schedule adherence is to that timepoint, the next timpoint on the route and the SCHEDULED departure time from that timepoint."

This timepoint system has been in place at AATA for quite a while. It's used in the paper guides and pdf versions of the schedule as well. The GPS system the implemented a while back incorporated to same concept and now it has been similarly passed on to the web tracker. So it's a little like the rocket based on a horse's ass.

We now understand the reason behind the format. And based on the "status" reports we've seen, you can pretty much expect the bus to be within a couple minutes of schedule anyway. However, all that doesn't keep us from wanting to know when the bus will pick us up at our stop.

We'd love to hear other's thoughts on the new feature, and so would AATA. Be sure to give some feedback when you try it out. We should also remind folks that UM buses offer a similar feature in a different format as we mentioned before.

For those reading this hot of the press, Bobbie warns that they are moving servers in response to high volume and this may affect service for a brief period. So don't give up if it fails on your first try.

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