GLASGOW’S subway has closed for four weeks to allow modernisation works to take place.

Strathclyde Partnership for Transport (SPT) said the “essential works”, to be completed by July 31, involve a full replacement of the section in the tunnels known as ‘’ramps and turnouts’’.

July was chosen for the work as passenger numbers show summer is the quietest time of year, SPT said. A replacement bus service following the underground route will run for passengers during the four-week period.

The work is part of a £288 million modernisation programme that will see the introduction of driverless trains by 2021.

SPT chairman Jonathan Findlay said: “To date, SPT has achieved all of the modernisation works without any disruption to passenger service, which is a considerable achievement.

“We have now reached a crucial stage in the modernisation plan that requires us – for reasons of safety for everyone involved - to suspend services for a short time during July.

“We apologise for any inconvenience to all our passengers but our full replacement bus service will mean that they can still get to where they want to go.

“All our passengers are encouraged to turn up at their designated stop, allow a little longer for their journey, and leave the rest to us.”

The replacement buses will include additional direct services to the city centre from key stations such as Bridge Street, Kelvinbridge and Shields Road.

Fares will be £1 for a single journey, £2 for a return and £2.50 for an all day ticket. Child fares are 50p single and £1 return.

Services will be every five minutes at peak times and every ten minutes during off-peak.