OC Transpo is advising customers to prepare for more bus trip cancellations today and this week, as the transit service deals with a staffing shortage caused by summer vacations and sick leave absences.

The transit service cancelled hundreds of bus trips across the city of Ottawa over the past five days, many at the last minute, leaving frustrated transit riders waiting at the bus stop for the next bus.

There were 46 cancellations Monday between 4:30 a.m. and 4:30 p.m., According to the Twitter feed OCTranspoLive.

"We know that the number of trips that we are unable to deliver right now is not meeting our customers expectations," Troy Charter, director of Transit Service Delivery and Rail Operations, told CTV News Ottawa on Friday.

"Obviously, our goal is to minimize this as quickly as possible, but at the same time we want to give our customers a bit of a heads up that it could potentially continue on for another week or two."

The OCTranspoLive Twitter feed showed that the transit service cancelled 69 bus trips by 8 p.m. on Sunday, while more than 210 trips were cancelled on Saturday.

OC Transpo reported 324 trips were cancelled on Wednesday (four per cent of all scheduled trips), 324 trips cancelled on Thursday (four per cent of all trips), and more than 200 trips were cancelled on Friday morning.

"We anticipate that customers could continue to be affected by the non-delivery of trips into next week based on a few short-term factors, including the number of staff who worked overtime last week while O-Train Line 1 was being repaired, higher-than-usual sick leave absences, and normal seasonal vacations," OC Transpo general manager Renee Amilcar told council on Friday.

"We are working hard to improve delivery of scheduled trips by asking staff to extend their workdays and through overtime hours."

Amilcar says OC Transpo is making "every effort" to improve service reliability for the balance of August and to prepare for September, when tens of thousands of students return to the system.

A new group of 32 bus operator trainees are set to graduate in mid-August.

UNION HEAD WARNS OF TROUBLE IN THE FALL

Clint Crabtree, Amalgamated Transit Union Local 279 president, tells CTV Morning Live he's been warning of these issues since the spring.

"There are going to be issues with the schedules and it's going to be even worse when it comes to the fall," he said. "I think the schedule in the fall is going to be very, very bad. It's going to be a hard time for the public and a hard time for my members because the public will be very unhappy with the schedule that's put forward by OC Transpo."

Crabtree pushed back against allegations of absenteeism and vacations as a cause for driver shortages at OC Transpo.

"That's totally being deceitful and lying. Vacation is planned every year. They know how much staff they have and they plan the vacation around that. To say that vacation is causing this as well is totally false," he said.

He says morale at OC Transpo is at an "all time low."

"They're very unhappy with the way this has been put forward by their employer. They feel like they have no support out there and they're feeling it from the public because the public is very unhappy and you can't blame them," he said. "They want reliable transit, they deserve reliable transit, and they're not getting that."

He says since drivers are often the point of contact for most riders, they're bearing the brunt of complaints.

Crabtree says schedule adjustments are a priority.

"The scheduling they've put together and the planning is not working," he said. "They need to get this right, right away."

Charter says, with more drivers set to be hired and trained, he believes service in the fall will be better.

"I think we'll see improvements in the fall. That's been our focus throughout the summer, but we'll have to see how things play out," he said.

Thirty-two bus operators are set to graduate this month to help boost service, with a goal of hiring 300 new drivers by the end of 2022.

O-TRAIN SHUTDOWN

As transit users deal with cancelled bus trips, sections of the O-Train will soon be offline during the evenings for two weeks.

Sections of the Confederation Line will close as early as 8 p.m. from Aug. 12 to Aug. 25 for maintenance work.

"Every light rail system requires regular proactive maintenance annually to ensure the long-term sustainability and reliability of the system," Amilcar said. "As noted previously, this year’s scheduled maintenance work, and in particular rail grinding and profiling, will ultimately improve ride quality and customer comfort."

Maintenance activities will include switch heater calibrations, rail repairs and replacement, inspections of the track and rail grinding.