The Scania Euro 6 vehicle is set to join the ACTION bus services from Wednesday.

ACTION has already taken delivery of seven of the 66-passenger buses and Mr Rattenbury said they will join the network over the coming months.

Bus 539, which will be the first passenger bus in Australia to meet the strict Euro 6 emissions standard for large vehicles, cost the government more than $460,000.

Each of the vehicles provides passengers with state-of-the-art safety features, heating and cooling, lowered floors for wheelchair accessibility, and seating for 48 people.

Mr Rattenbury said the new vehicles would be fully rolled out by 2018, significantly decreasing particle pollution and nitrogen oxide emissions from Canberra's bus fleet.

The buses are ready for the launch of the real-time NXTBUS tracking system and would replace some buses that have been on the road for more than 25 years.

“The new buses are fuel-efficient and produce minimal harmful pollutants," Mr Rattenbury said. "They’ll help keep Canberra’s air clean and reduce pollution.

“The Euro 6 diesel buses emit approximately 80 per cent less nitrogen oxide and 90 per cent fewer diesel particulates than the previous Euro 5 engine models. It’s important we reduce these particular pollutants as they are harmful to people’s health and reduce local air quality.

"They have been designed with a focus on passenger comfort and vehicle safety, and are built to withstand 20 years in operation."

Public transport watchers and ACTION chief operating officer Bren Burkevics joined the ceremony outside the ACT Legislative Assembly on Tuesday.

Mr Rattenbury said he would like to see more Canberrans use public transport. "I would really like to see more people taking the buses. I think there's a bit of a reputation issue for ACTION where people think, 'The service doesn't suit me', or 'I haven't tried it for 10 or 15 years'.

"I would really encourage people to give ACTION a go. So many people have positive feedback about the bus service and it's a great way to travel."