Rail passengers in Scotland are experiencing major disruption on a day when residents of the country's biggest city were advised to use public transport.

A signalling fault at Yoker, in west Glasgow, has led to the closure of an entire line in the city and is having a significant knock-on effect on other services.

ScotRail said trains between Glasgow and Whifflet, Falkirk, Cumbernauld, Milngavie, Dalmuir, Balloch and Helensburgh will all be cancelled or delayed until at least 9pm.

The fault is also affecting services to Edinburgh via Bathgate and the Motherwell to Cumbernauld line.

Meanwhile, another signal fault in Aberdeen is causing delays on services between the city, Glasgow and Edinburgh. ScotRail said it expects this disruption to last until at least 4pm.

In total, seven of 30 ScotRail routes are affected, almost a quarter of the network.

The disruption comes as dozens of roads across Glasgow have been closed for the European Championships cycling time trials.

Commuters in and around the city were advised to use public transport for their travel today, a decision many people are now regretting.

Lothian MSP Neil Findlay tweeted from Bathgate station: "On the day Glasgow city centre shuts down because of the cycling - everyone gets turfed off the train at Bathgate because of a signalling fault - any chance of @Scotrail advising what is happening to the passengers who are stranded and are travelling to Glasgow ?"

Other passengers have been left stranded by the cancellations, with no way to get home.

Karen King tweeted: "@Scotrail are the issues sorted so people can get a train from Glasgow central to Singers yet?

"Currently have two family members, pensioners with mobility problems stuck in city centre. Bad enough with road closures without another sterling effort from #scotfail."

And a Twitter user named Dave added: "I'm used to @ScotRail being a shambles commuting to work, but when my mum can't get to the Beatson for a vital hospital appointment, on the same day the roads are all blocked, it becomes disgraceful. Will you ever get your act together??

ScotRail said replacement buses have been rolled out to replace cancelled trains.

However, the road closures mean that in some instances buses are unable to get to affected rail stations.

Helen Vass tweeted: "@Scotrail trains to Milngavie are cancelled but told tickets accepted on bus routes.

"There are no buses running to Bearsden and Milngavie area due to road closures for #EuropeanChampionships2018 cycling."

A ScotRail spokesman said the disruption was caused by the failure of Network Rail infrastructure.

He added: "We are sorry to our customers experiencing disruption as a result of a signalling fault.

"Network Rail has advised us that the signalling has been restored, but due to the severity of the disruption it will take time to return to a normal timetable as trains and crew are out of position.

"Customers are advised to check our app or @ScotRail on Twitter for the most up to date information."

Network Rail did not reply to STV's request for comment.