Don’t quote me but the Trafford Centre service seems to have gone from about every 10 minutes a few weeks ago up to about every 15 just now when I’ve got the tram. I’m happy to be corrected on this, it was just an observation.
As for pre-Covid, I couldn’t say. I’ve only recently become a frequent user of the service.
TPL has reverted to it’s pre-covid service pattern of every 12 mins. There have been issues with staff shortages this week which has led to a reduced frequency at times though.
Timetable has been a bit funny lately, I think they’ll unify the services to a 12 minute frequency, with an average of 6 minutes (on the SML it’s runs so East Didsbury trams run in intervals of 8 then 4 minutes) because services double up from certain origins, like East Didsbury - Shaw and Crompton/ Rochdale, or Altrincham to Market Street/ Bury (with the former running to Piccadilly Gardens or Etihad Campus if they are resuming the Early 2020 timetable).
That’s incorrect I’m afraid.
The SML service is every 6 mins and is timetabled as such. Obviously services can run late which can give the impression of a different frequency but I assure you it is times for every 6 mins. Sets interwork on this line, so a set coming into Didsbury from Rochdale will work to Shaw and vice versa.
Altrincham and Bury line services are also every 6 minutes through the day. For the Alti Line the core service is Altrincham to Piccadilly, not Piccadilly Gardens (possibly during engineering works) or Market street (not possible). This runs all day.
On the Bury side the core service is Bury-Piccadilly. Again, running all day.
From start of Morning peak to end of evening peak these are supplemented by the Altrincham-Bury ‘directs’ which make up the 6 minute service.
This is exactly how it was pre-COVID. The only line that hasn’t returned to pre-COVID service levels is the EML, which currently has its 6 minute service only running as far as Etihad Campus.