However, rail chiefs admitted the move is designed to reduce the need to order replacement buses.
Under the scheme, launched today, ScotRail passengers will be offered alternative travel on First Glasgow buses, if "severe disruption" affects selected rail routes out of Glasgow Central and Glasgow Queen Street.
ScotRail bosses said if the new system proves successful, the train operator will consider expanding it to other stations and routes.
A ScotRail spokesman said: "If severe disruption affects selected rail routes ticket-holders will be able to exchange rail tickets for vouchers for use on the appropriate First Glasgow bus service."
Steve Montgomery, ScotRail's Managing Director, said: "I hope the trial will reduce the need for us to order replacement buses. It can take up to an hour for these to reach Glasgow city centre – or even longer during bus peak travel times."
ScotRail today also welcomed figures which reported no alcohol- related arrests on services during Christmas and New Year.
This was the first year that festive revellers were prevented from consuming alcohol on its trains between 9pm and 10am.
The operator and British Transport Police thanked rail passengers for their response to appeals to stay safe on the rail network.