Lothian Buses faced fine for bad service
The firm could face a warning, a fine or, in an extreme case, the withdrawal of its licence.
Sources today suggested the problems were a result of the tram works playing havoc with running times.
The commissioner's office confirmed that an inquiry was set to take place next month and said the firm would have good opportunity to defend itself against any charges levelled against it.
The probe follows a monitoring exercise following complaints about buses not sticking to timetables.
It is understood to be the first time the council-owned bus company has faced such a probe. However, similar cases elsewhere have seen companies forced to pay out tens of thousands. In 2006, two bus firms in Dorset were fined a total of 63,000 for services which ran late or not at all.
One source said today the blame would be laid on the tram disruption. He said: "This goes back some months and was caused by the disruption left by the tram works.The timetables were slackened off during the works to allow more time for the buses which were running late, but then the tram works were taken away and the buses ended up arriving early."
Retired university researcher, Harry Watson, 64, was one of those to complain about the 41 bus and welcomed the inquiry.
Mr Watson, who lives in Cramond, said: "Quite often you find the timetable just doesn't work. Coming back to this part of the west of Edinburgh, the 41 is our local bus, but sometimes we end up going for one of the buses to South Queensferry or Fife, which are not run by Lothian Buses, in desperation.
"The tram works are certainly part of it, but I don't think they can blame everything on that."
SNP Lothians MSP Shirley-Anne Somerville said she hoped the investigation would take into account the difficulties caused by the tram works.
She said: "I certainly hope the traffic commissioner shows a little understanding of the near impossible situation Lothian Buses has been put in over the past couple of years."
Ian Craig, Lothian Buses' managing director, said: "The inquiry will give us the opportunity to reaffirm that the punctuality and reliability of our services is of the upmost importance to us and our passengers."
Are you fed up with the buses not running on time?
Diana Atkinson, 78, retired, Greenlaw Rigg: "I've experienced this problem many times but I have the utmost sympathy for them. Traffic is so congested."
Robert Cockburn, 80, retired, Currie, Midlothian: "I'm not surprised they're running late with all of the roadworks in the city. I think the buses are doing a cracking job and people should be more tolerant."
Christopher Day, 55, choreographer, Dundas Street: "Buses round my way are so frequent that I barely look at the timetable, but I suppose I'd be annoyed if I had to be somewhere on time."