Electrification: Valley lines 'need more train capacity'
More trains and carriages will be needed on south Wales valleys lines once the London to Swansea line is electrified, a transport group says.
Sewta said services in the south Wales valleys had already seen an 80% growth in passengers since 2000 and it fears overcrowding after electrification.
The London-Swansea line is set to be electrified by 2018 with the valleys network by 2024.
Sewta has launched a consultation on its strategy for rail improvements.
The south east Wales transport alliance is made up of 10 local councils and rail organisations.
The south Wales rail electrification was announced last summer by the Department of Transport.
It is scheduled for completion by 2018 with the Cardiff and valleys network to follow at a cost of £350m between 2019 and 2024.
Sewta said electrification "strengthens the case for a host of further enhancements" to the network.
Its strategy document says more room on trains will be needed to cope with the anticipated extra passengers using the south Wales valleys network.
Some valleys services have seen a passenger rise at a faster rate than the average for England.
It said: "In the last decade rail passenger demand on the Valley Lines has been growing at around 6% per annum with some lines experiencing 80% growth between 2000 and 2009, significantly higher than the average for the UK."
It added: "Additional rolling stock is required to strengthen peak trains to address passenger growth and to avoid overcrowding."
Sewta's strategy calls for the whole rail network in south east Wales to be electrified by 2030.
The improvements it recommends include:
- Opening 17 new stations
- Extensions to existing lines
- Lengthening some platforms at existing stations.
Sewta chair, Councillor Phil White, of Bridgend council, said: "This report sets out an exciting programme for the next two decades.
"I would encourage communities and businesses throughout the region to let us know what they think about the priorities set out in the report."
Sewta's strategy documents are open for consultation until 30 September.