The Scottish Government has given the go-ahead to a £63m electrification scheme to the south of Glasgow but a linked scheme will now only be single track.
Transport Scotland said construction work is expected to get underway on the Barrhead corridor in April 2022 and due to be complete by December 2023.
The project will support passenger and freight services and will be used as a key diversionary route for cross-border services. It has been developed by Transport Scotland and Network Rail and will pass through East Renfrewshire and South Lanarkshire.
The existing railway between Busby Junction and Barrhead consists of 12km of non-electrified single track.
Transport Scotland also said that the linked East Kilbride corridor ‘has recently been given approval for single track electrification infrastructure, and further development work is required to support this’.
Former infrastructure secretary Michael Matheson had previously said that alongside electrification, part of the East Kilbride route would be ‘turned into a dual route, which will help to improve passenger services’.
Transport Scotland said the projects ‘are being taken forward in the face of the significant financial challenges, and in light of uncertain future demand’.
It added: ‘By progressing with single track this allows funds to be reallocated to other decarbonisation projects such as Borders electrification.’
Transport Scotland had previously said: ‘The ultimate goal is to run four trains per hour during peak times (07.00-10.00 and 16.00-19.00), with longer, quieter and greener trains providing a punctual and reliable service that will continue to make rail travel an attractive choice for passengers and reduce car usage to and from Glasgow.’
The backtraking will raise further questions over the Scottish Government’s commitment to ‘align transport policy with our climate targets and the goal of reducing car/km by 20% by 2030’, as set out in its agreement with the Scottish Green Party.
The agreement also states that work on trunk roads projects and programmes under construction, design, development or procurement will continue and be subject to the normal statutory assessment and business case processes, while ‘the future direction of investment in Scotland’s railways will be determined as part of the second Strategic Transport Projects Review’.
The two rail routes were cited in the Scottish Government’s ‘Infrastructure Investment Plan for Scotland 2021-22 to 2025-26’, published in February, which pledged £550m on a Rail Decarbonisation Action Plan over the five-year period.
Transport minister Graeme Dey said the cut would ‘ensure the decarbonisation of two critical corridors [and] allow efficiencies to be achieved and disruption minimised for passengers during this period’.
‘I’m pleased that work on the full electrification of the Glasgow to Barrhead railway line is expected to start early next year as this will make a significant difference to passenger and freight services in the future,' he added.
‘It will also help towards the delivery of our Rail Decarbonisation Action Plan, which will see removal of all diesel on passenger services by 2035 through the deployment of existing rolling stock.’
Katie Vollbracht, of Network Rail Scotland, said: ‘The East Kilbride and Barrhead Electrification Project is at the centre of our plans to decarbonise domestic passenger services by 2035.
‘The project will deliver high-quality public transport choices for passengers through the introduction of greener, more reliable electric trains, with improved stations and passenger facilities along the two routes.’
Transport Network has approached the Scottish Green Party for comment.
Road Expo Scotland and Bridges Scotland will take place from 1-2 December 2021, returning to the purpose-built SEC Glasgow.