Why are we "predicting" at all?
Why doesn't every bus have a tracker that tells you exactly where it is at all times?
This is 2018. GPS with refinement isn't rocket science anymore.
Tell me where the bus is and I'll do my own prediction thanks.
- Time. Time has the advantage of brevity ("15 min" takes up a grand total of five characters) and indisputable meaning. It's also the hardest to predict, and people get pretty upset about incorrect predictions.
- Intersection. On a signboard, intersection names can get quite long. You would also need familiarity with where exactly the intersection is located, how the bus gets from there to your stop, etc. Boston is famously non-gridded, and has no real consistent rhyme or reason to its street layout, so that would be very confusing.
- Miles/stops away. New York's BusTime uses this. This is a pretty indisputable metric, and if you have GPS or a working odometer is trivial to confirm. But this runs into the same problem as intersections; you need context. The bus is two stops away, but how long does it take to make those two stops? A mile passing through Times Square is very different from a mile through the leafy, quiet suburbs of Queens.
You can pick between meaning and certainty, but it's very hard to have both.
I have found One Bus Away to be completely inferior, to the point that I usually don't bother to check it.
The problem is that they should have spent 0% of their time on prediction and 100% of their time on actual tracking.
Once you have tracking, prediction pretty much comes along for the ride.
Same with the train - I use a website that shows the exact locations of all the MBTA trains, and I am able to accurately predict how long the train will sit outside of the Alewife station (which is infuriating BTW) based on the number of trains currently at the platform. A prediction would not be able to take into account this domain knowledge and would be completely worthless.
This x100.
I do this all the time with Lyft drivers. "No, please don't listen to Google Maps for this. The route it is trying to take you on goes from totally open to totally clogged over the span of 6:45AM to 7:00AM. Trust me, the route I am having you take me on will be faster by the time we get there."
People are way more clever than you think.
I have worked in support for a well known GPS navigation software and the GPS accuracy is terrible for most consumer devices. You have to spend a lot of money in a GPS receiver to get past this accuracy issue. What Lothian buses (the company I have mentioned above) have done is using something lower tech to replace the need for such an expansive device. And overall it does work surprisingly well even in heavy traffic occurrence (road work, rush hours, etc ...).
And that is basically what is happening early next year.