Reasons for change in the Journey Planner xml files

It is not of major significance but I am intrigued as to the reason for changes about a year ago in the naming convention for and the contents of the Journey Planner files in the Datastore zip files.

Once upon a time, life was simple. Working timetables used a 5 digit code (Service Change Number) in the text. The Journey Planner files in Datastore would also use a 5 digit number. There would usually be a JP file for each set of WTTs.

It weas never quite that simple, as special timetables for quite a few routes were often represented by a 5 digit code that had no equivalent amongst the WTTs. These extra 5 digit codes were, it seems, typically created by incrementing a SCN already used for that route by 1 (with enough specials you could end up with as many as 20 extra 5 digit codes). Some WTTs also had no JP equivalent file, presumably because the change made did not impact on the timetable. So it was not a nice tidy 1:1 or 1:many relationship but by-and-large you could match them up.

Then along came the change of system to Adiona for WTTs (and presumably everything else). Since then (a year go now) nearly all JP files have had concocted 5 digit codes with no link at all to the codes in the WTTs, even those that clearly correspond to a very definite service change. I am intrigued as to why this change happened; was there something in Adiona that made a link no longer of use within TfL (if the link ever had any use)? It is hardly a major issue for users but it does offend my sense of tidiness!

The more important change that started to affect the JP files a few weeks (U think) after the new style WTTs was that all stops suddenly got described as PTP (proper timing points). Previously this status was reserved for stops used as timing points in the WTTs (and presumably for service monitoring). Other stops were described as OTH. The loss of this distinction again makes it harder to concoct a timetable with just the main timing points from the JP files, as you have to make the distinction for yourself.

Seemingly as a consequence, all running times between adjacent stops are now shown as whole minutes. Previously only running times between PTPs were constrained in this way, running times involving OTH stops being given in seconds. Spurious accuracy of course but that’s the way it was.

Again, I find myself wondering why this change was made.