The new £90m Glider bus service is fulfilling its aim of attracting more people to public transport, the head of Translink has said.
The Glider buses became fully operational in Belfast last Monday.
Chris Conway, the company's chief executive, said it was too soon to provide exact figures on usage.
But he told BBC Radio Ulster's Inside Business programme it was performing "extremely well" after its first week.
"If you look at the capacity we normally had on the routes versus what we are are putting on with Glider, it tells us more people are using it," he said.
The Glider buses link east and west Belfast and Titanic Quarter with the city centre.
They have been described as "a tram on wheels".
Mr Conway said it was an "unfortunate coincidence" that the launch coincided with problems with Translink's mLink mobile ticket app for buses and trains.
He said the service's supplier had been unable to cope with a surge in demand across the UK caused by people returning to work and school after the summer holidays.
You can hear Mr Conway's interview on BBC Radio Ulster at 1.30 on Sunday, with the programme repeated at 6.30 on Monday.