The TFL system will remove a bus if it doesn't get an update often enough that includes actual progress on the route. This is in fact the opposite problem of what you mention, in that they don't do a very good job of predicting based on past performance. E.g. I used to take a specific bus to pick my son up from nursery that always would "disappear" for a certain number of minutes at a certain part of the journey because a very short stretch of the route was always extremely congested at that time of day.
It's a tricky one, because they have big concerns about over-promising (e.g. the bus could be stuck behind an accident instead, in which case guessing that it's 5 minutes away because of past behaviour will really annoy people) so in some situations they err on the side of caution.
But they are unable to get rid of all of the corner cases. E.g. a bus that moves rapidly for a short stretch, then gets "stuck", will often appear, disappear, appear, disappear, with much less progress in time estimates than elapsed time should indicate.
The thing is, the team working on it has a huge amount of gathered info on how to give these predictions in a way that tries to minimise surprise and avoid making promises that cause problems for people. E.g. often it's better to take a bus off the list so people who are in a hurry will grab a taxi, rather than "promise" the bus will be there in just another few minutes. They still get it wrong too often, but I really don't envy them trying to get the right balance between promising too much and too little.
It's a tricky one, because they have big concerns about over-promising (e.g. the bus could be stuck behind an accident instead, in which case guessing that it's 5 minutes away because of past behaviour will really annoy people) so in some situations they err on the side of caution.
But they are unable to get rid of all of the corner cases. E.g. a bus that moves rapidly for a short stretch, then gets "stuck", will often appear, disappear, appear, disappear, with much less progress in time estimates than elapsed time should indicate.
The thing is, the team working on it has a huge amount of gathered info on how to give these predictions in a way that tries to minimise surprise and avoid making promises that cause problems for people. E.g. often it's better to take a bus off the list so people who are in a hurry will grab a taxi, rather than "promise" the bus will be there in just another few minutes. They still get it wrong too often, but I really don't envy them trying to get the right balance between promising too much and too little.