Offer pessimistic predictions api for transfers?

[Jeff Kaufman]

You could describe the current predictions nextbus makes as
"optimistic"; if the bus could arrive in 2-5 minutes the API seems to
generally predict "2 minutes". This is generally a good choice,
because if you predicted the most likely time for the bus to arrive
people would get their at that time, have missed their bus, and be
mad.

But there's at least one situation when you want the predictions to be
biased the other way: transfers. Someone is riding on bus A and
trying to figure out if they should get off at stop 1 and catch bus B
or stay on until stop 2 and catch bus C. In general A-C is best for
them, but bus A is running late and they're not sure they're going to
make their transfer. I'd like to include something in my app that
tells them either:

1) a pessimistic (latest case) prediction for when bus A will arrive
at stop 2, which I can combine with the normal optimistic (earliest
case) prediction for when bus C will arrive at stop 2 to predict
whether the transfer will work, or

2) an api that will directly answer questions like "what is the
probability that the vehicle with id X will get to the stop with id Y
at least N minutes before the vehicle with id Z will get to the stop
with id W".

Have you thought about communicating this kind of information about
transfers at all?

Jeff