Thousands of rail passengers in Scotland face travel misery as signal workers stage the first of two strikes this week.

Network Rail workers will walk out for 24 hours from noon and are set to strike again on Thursday from the same time.

Services will wind down after the morning rush-hour, hitting all major routes north of the border.

Last-ditch talks aimed at averting the action collapsed after a failure to reach agreement on a dispute over staff rosters.

The Rail Maritime and Transport (RMT) union and Network Rail could not resolve the row despite hours of negotiations.

Around 450 workers are set to strike in the action, which will stretch over four days. Operator First ScotRail has warned journeys will be "severely disrupted".

As well as the strike, a ban on overtime and rest-day working starts at the same time.

Thousands of passengers will face cancellations or disruptions as hundreds of journeys are cut.

Services on the major commuter route between Edinburgh and Glasgow will be reduced by around half.

The journeys of people returning home later will be hampered, and the disruption will continue during Wednesday morning's rush-hour.

No trains will travel north of Stirling, and replacement bus services will be put on to cities including Aberdeen and Inverness.

First ScotRail said it would run "as robust a timetable as possible in the circumstances".

Despite hours of talks in Glasgow mediated by conciliation service Acas, the two sides have been unable to resolve the dispute.

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