PASSENGERS can expect carriage doors to shut 15 seconds before the train is due to depart as Scotrail introduce a raft of measures to improve punctuality after missing one of their contractual targets.

The rail operator, which has come in for criticism for its poor performance in recent weeks, has released a performance improvement plan after missing the target for reliability and punctuality of 90.3 per cent outlined in its contract with Transport Scotland.

That plan means that within the next few weeks, three new trains will be brought into service, a campaign will be rolled out to staff and the public aimed at getting trains running on time, vegetation will be cleared from around the tracks and signals will be improved.

David Dickson, ScotRail Alliance infrastructure director, said the dip in performance had come at a time of "unprecedented change" on the network, including major upgrade works which partially closed Glasgow's Queen Street Station.

He said: "Our performance isn't good enough and we have to hold our hands up. It's not where we want to be. We do need to get our level of performance up.

"On some routes we have excellent service so its really about 'how do we drag the other ones up?'. They are the ones we need to do something about.

"We know we are coming up short with the overall performance so that is why we are coming up with these plans to bring things up to what people expect."

The rolling improvement plan is expected to cost the company an extra £16 million over the next two years and officials said they are confident it will boost performance.

It is understood that further missed targets could see Transport Scotland taking a greater oversight of Scotrail's operations.

Mr Dickson stressed that getting trains out of their stations on time was key to the plan, leading to the introduction of a 15-second cut-off before the train is due to leave.

A number of longer-term improvements also include the identification of so-called "golden trains", which if delayed have the greatest impact on the network and can cause knock-on delays for up to two hours.

He said: "The improvements are not the sort of stuff you will look out the window and see dramatically changed. It will just be that there should be less disruption to passengers' services. More on-time running, fewer cancelled trains, and just a more reliable service overall.

"Focussing on time is a huge thing for us. If we can get trains to start on time, they hit the junctions on time and get to the other end on time."

The Scottish government can also trigger a clause to remove the contract from Dutch company Abellio if punctuality rates drop below 84 per cent.

However, Scotrail have insisted that it is "a million miles" from this point.

A petition with 19,000 signatures calling for Abellio to be stripped of the ScotRail contract was handed to Transport Minister Humza Yousaf earlier this week.

It calls for the Scottish government to act over delays and cancellations, but Scotrail spokesman Rob Shorthouse said that it would dictate the work needed.

He said: "The petition is the petition and we're not going to criticise anybody from signing it, but we're not going to use that as the basis for the improvements."