Rail travellers will be able to use the newly-reopened Vale of Glamorgan line for the first time from Sunday.
The service will link up to Cardiff International Airport
The line, which runs from Cardiff to Bridgend via Llantwit Major, has re-opened to serve Cardiff International Airport.
Around £17m was needed to pay for the service, which includes new stations at Llantwit Major and Rhoose.
However, there are complaints about the frequency of service and that air travellers still need a shuttle bus.
The old railway line has been shut to regular passenger services since 1964, but has been revamped with investment from the Welsh Assembly Government.
On Friday, Transport Minister Andrew Davies performed the official re-opening at Bridgend. Ceremonies were also held at new stations in Llantwit Major and Rhoose.
Mr Davies said it was an historic day for transport in Wales.
"The restoration of passenger services to the Vale of Glamorgan after 40 years represents a major milestone in the delivery of an efficient and integrated transport infrastructure for Wales," he said.
Passengers will take a shuttle bus to the airport
Responding to criticisms that the station should have been closer to the airport, he said the terminal was on the wrong side, and so ruled out the possibility.
"To change that would be huge expense but obviously we will be working with the airport to improve services," he added.
Welsh Conservatives, however, said the frequency of the service from Cardiff to the airport meant its impact should not be overstated.
"With services from Cardiff to the airport scheduled for just once every hour, I cannot see how this will reduce the need for people to drive," said the party's transport spokesman Alun Cairns.
Meanwhile, estate agents have predicted a mini-property boom in Llantwit Major.
Staff have already begun taking inquiries from people wanting to move there - because the hourly trains will make it easier for them to live by the sea and work in Cardiff.
House prices are not expected to rise substantially, but houses should sell faster, said estate agents.