Cabbies are being paid £3 by rail officials to ferry some passengers between platforms at one train station.
Another redevelopment will take place before the Ryder Cup
A new £5.5m platform at Newport does not have a lift for disabled or elderly people or passengers with pushchairs.
Network Rail says building a lift now will cause disruption, but there will be one in another redevelopment when the city hosts golf's 2010 Ryder Cup.
The Disability Rights Commission says it is not ideal, but the firm is within the law as it is providing access.
The only access to the 270m (885ft) platform four is either a long walk through a car park or through the station over a footbridge.
But both routes are too difficult for passengers with mobility problems.
They are now being helped into a taxi and driven half-a-mile (0.8km) around the station to reach the new platform.
A Network Rail spokeswoman said: "The taxi service is there as and when needed and can be accessed via a help-point on the platform."
A local taxi firm has been commissioned to ferry passengers who need help to the new platform at the station, which is on the main line between south Wales and London Paddington.
The situation will change in time for the Ryder Cup, one of the world's biggest sport events, being held at the nearby Celtic Manor Resort in 2010.
The spokeswoman added: "Lifts will be put in a new station development by the time of the Ryder Cup in 2010.
"To do so now would require a lot of development work and we did not want to delay the extension."
A Disability Rights Commission spokeswoman said: "It seems a bit strange if this was a new development that it wasn't thought about."
Conservative AM William Graham also criticised the lack of disabled access, although he said he appreciated that it was being provided free of charge.
"However, a wait until the Ryder Cup in 2010 for lifts to be installed is not an answer," he said.
"Disabled access should have been an integral design feature from the very beginning of this project".