Ottawa transit riders are dealing a fourth day of frustrations and waiting for the bus, as a staffing shortage resulted in hundreds of cancelled bus trips across the capital.

"We have been heading towards this type of crisis in our transit system for sometime," Coun. Catherine McKenney says.

According to the Twitter feed OCTranspoLive, more than 210 bus trips had been cancelled as of 10:30 p.m. on Saturday. OC Transpo reported 324 trips were cancelled on Wednesday, 324 trips cancelled on Thursday, and more than 200 trips were cancelled on Friday morning.

McKenney told Newstalk 580 CFRA on Friday that Council's approval of an OC Transpo route optimization plan in 2011 to save $20 million and the elimination of over 100 buses and driver positions with the launch of light-rail transit left the system vulnerable to staffing issues.

"We've got an extreme shortage of drivers, buses – we just don't have any extra capacity in the system, anything goes wrong and your bus doesn't show up," the mayoral candidate said.

OC Transpo has warned the high number of bus trip cancellations could continue into next week due to a number of "short-term factors."

"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 said in a memo on Friday.

Amilcar says OC Transpo is "making every effort" to improve service reliability for the balance of August and to prepare for September.

"Very frustrating, very inconvenient. Not what we want, we want reliability – that is the number one job of a transit system," Coun. Theresa Kavanagh told Newstalk 580 CFRA's Ottawa Now on Friday.

Kavanagh says when people rely on public transit to get to work, school or run errands, they need reliable service.

"You hear about individual cases where somebody couldn't get to where they had to go and lots of frustration, especially for people who have to change multiple times to get to a destination … if that link is broken they've really got a problem," Kavanagh said.

OC Transpo says 32 new bus operators will come on-board in mid-August to help relieve the staffing crunch and boost service.

Kavanagh says the COVID-19 pandemic and the upcoming launch of Stage 2 of the LRT system presents the city with a chance to change the transit system.

"What routes are really needed? That is the big question," Kavanagh said. "Some routes have empty buses, I think everybody knows that, but there's a few people that really depends on them. These are tough decisions."

OC Transpo operates approximately 7,900 trips a day. The transit service continues to run below capacity during the COVID-19 pandemic as employees with the federal government and other businesses continue to work from home and lifestyles have changed.

Ridership numbers for June, released by Coun. Glen Gower on Twitter, show 3.8 million passengers used public transit, below the 2022 budget of 5.8 million expected passengers. In 2019, 6.8 million passengers used public transit in June.

Kavanagh says the city must work with the federal government and other major employers to look at the future of the office and commuters using the transit service.

"The reliability is really important, but we have to look also at who's our customer base, where are they going and do they need monthly passes – maybe they don't anymore."