Bus operator First has put 16 new vehicles on two routes running between the centre of Bristol and Emersons Green.

The double deckers, which cost a total of £2.7 million, are the first low floor buses to operate the 48 and 49 routes.

They will make it easier for parents with pushchairs and in wheelchairs to get on board.

They also have more comfortable seating, digital CCTV security systems, designated space for wheelchairs, prams and buggies, satellite tracking units and low-emission engines.

First is now delivering more than 20,000 leaflets to homes along the route taken by the buses to let people know they are in service and to offer a half-price off-peak ticket to travel on them.

Justin Davies, the company's managing director for Bristol, Somerset and Avon, said: "These new buses should make a real difference to the 48/49 routes, which have not had low-floor vehicles before."

The buses are the latest to be bought to upgrade the First fleet.

Between the autumn of 2007 and the end of this financial year, the company will have spent £20m on 131 new buses to operate on the greater Bristol bus network.

First said the latest 16 in use replaced vehicles that were at least 15-years-old.

Each seats up to 74 passengers, with room for 14 to stand, and are fitted with engines that meet up-to-date emissions standards.

Mr Davies was joined by Brian Allinson, South Gloucestershire Council's executive member for transport, in Staple Hill when the buses went on the road for the first time.

He said: "We know good quality buses are one of the key ways of attracting greater bus patronage. I hope more South Gloucestershire residents will be encouraged to travel by bus and help us tackle congestion."

Service 48 follows a route from the city centre through Eastville, Fishponds, Downend and Blackhorse to Emersons Green.

Route 49 also goes from the centre to Eastville and Fishponds but then travels through Staple Hill before reaching Blackhorse and Emersons Green.