OC Transpo general manager John Manconi is defending the bus service after lengthy delays on Canada Day.

"We moved a lot of people with a bunch of new dynamics at play, including people walking on the street due to some of the security checkpoints. In the middle of the afternoon we had a motorcade [for the royals] ... that literally shut down the Transitway in both directions in the core, and that caused over an hour of standstill in both directions, and those buses couldn't get back to their return trips," Manconi told CBC Radio's Ottawa Morning on Tuesday.

"Having said that, you can always improve, but overall we did a good job of moving a lot of people."

The OC Transpo plan changed about five or six times Saturday, Manconi said, to deal with situations as they arose.

Some buses were rerouted from rural areas to downtown Ottawa to deal with large crowds there, Manconi said. And the agency requested, and was granted, an Ottawa police motorcade to cut through crowds of people that had started walking directly on Albert and Slater streets during a temporary shutdown.

"It could have been a lot worse," Manconi said.

"To be fair, what you're not hearing about are the hundreds of thousands of people that loved the service. I was on the buses all day and you heard some cheers and I was on packed buses and people were appreciative. Free service."

Listen to the entire interview with Manconi here.