South Wales Metro impact on Valleys 'could take decades'
Valleys communities could be waiting decades for a boost from a new integrated transport system for south Wales, a leading economist has warned.
Prof Calvin Jones admitted the South Wales Metro plan had raised hopes that the Valleys would immediately benefit.
The Welsh Government said the Metro would be "transformational" as they hope first services will be running on the network by 2023.
But Prof Jones said the first places to benefit "may indeed be in Cardiff".
"This is a minimum of a 15-year to 20-year project," Prof Jones of the Cardiff Business School told the BBC's Sunday Politics Wales TV programme.
"The expectations of this process, between the shiny Metro and the reality of what will be an incremental long-term development, are very difficult to manage."
The initial work will be carried out to upgrade the existing Valleys lines and it is estimated that part of the billion pound scheme could cost around £734m up to 2023.
The Metro scheme promises better trains, faster buses and light rail or tram services in Cardiff and the south Wales valleys.
Welsh ministers are working towards making an application for funds by mid-2017, with construction to begin in 2019 and completion by the end of 2022.
The finance includes £125m from UK government funds and £369m from the Welsh budget.
First Minister Carwyn Jones travelled to the European Commission in Brussels on Wednesday in a bid to secure £110m of EU funding for the South Wales Metro project.
A Welsh government spokesman told BBC Wales the response in those meetings had been "encouraging".
Economy Secretary Ken Skates said the government hoped to "have diggers in the ground towards the end of this decade".
"The Metro will be a transformational piece of infrastructure for south Wales," he said.
"This will connect many communities that are currently feeling quite isolated and I've been very clear all along that the Metro should primarily serve the valleys communities.
"By 2023 we hope to have Metro services up and running."
Geraint Corkrey, owner of the Navigation pub and cafe in Treharris, in Merthyr Tydfil county borough, said: "We'd like to think that a Metro system with a stop in Treharris would bring people into the village.
"Hopefully that would benefit the local economy and boost the area in general, which personally I think is much needed."
However, Prof Jones warned: "The first places to benefit from the Metro may indeed be in Cardiff.
"The problem with that is people in Treharris don't want to wait too long."