Ottawa's big transit shift hits another gear Sunday, as major changes to bus routes are introduced in an attempt to better align the bus network with light rail.

Parallel bus routes that have been operating during the first three weeks of LRT service will end today. Most OC Transpo routes will also stop bringing riders into the downtown core, shuttling them instead toward the Tunney's Pasture, Hurdman and Blair light rail stations.

Other longstanding Ottawa routes, like the heavily-used No. 95, will be retired from service.

Pat Scrimgeour, the transit agency's director of customer systems and planning, has called it OC Transpo's "biggest service change ever."

Scrimgeour said they'll be keeping a close eye on the changes and will have extra buses ready to address problems that might emerge.

The transit agency is also open to altering schedules if something isn't working, he added.

"If we see a trend developing that there are a group of customers not being accommodated, we will make sure the arrangements are there for subsequent days," Scrimgeour said.

Sunday morning will come with changes to more than 100 OC Transpo bus routes. Many well-known buses will disappear from the downtown core. In this hour, OC Transpo's director of customer systems and planning answers your questions on the agency's biggest service change ever. 16:38

Look for red vests

OC Transpo has promised that removing the bottlenecks in the downtown core will make taking transit more reliable — the main criticism among riders who endured light rail construction for years.

The city has been advertising the changes for weeks, and Scrimgeour said there will be lots of people on hand to both help with the transition and offer advice to people whose commutes are changing.

"Look for anyone at any of our stations that is wearing a red vest," Scrimgeour advised transit users. "We will be happy to help you any way we can."

OC Transpo rider Moe Asgari says he experienced a bit of confusion trying to figure out how Sunday's bus route changes affected him. (Krystalle Ramlakhan/CBC)

Riders prepare

While the big test will be Monday morning, when people return to work, some riders like Anna Morris used Sunday as a chance to get used to the changes.

Morris said they would probably add 15 to 30 minutes to her commute.

"I don't think they've put enough thought into how they're handling the people in the suburbs. For the people that are living in the downtown area and are right off of the stations, I think it's going to work fantastic for them," she said, standing at Tunney's Pasture station.

"But the people that are in the suburbs, trying to get parking in park-and-rides ... it's adding [time] for some people."

Evlyn Peter says she'll now be taking light rail since the transit network overhaul eliminated the bus route she normally takes. (Krystalle Ramlakhan/CBC)

'I have no choice'

Moe Asgari said he knew the changes were coming, but was still slightly perplexed about how to navigate his route Sunday.

"It's a bit of confusion. Good thing that you don't see high traffic [today]," Asgari said.

"There are people that they just don't know what is going on. Maybe, I guess, because they never checked the information site. But overall, you know, you see it's all right. Everything seems to be in order, kind of."

As for Evlyn Peter, she'll be switching to the train since her bus route No. 57 no longer exists.

"I don't really like it," Peter said Sunday. "But I have no choice."