Monthly punctuality figures show the Bendigo line last reached its target of 92 per cent of on time services in May 2015.

On commuter services, V/Line measures punctuality to five minutes 59 seconds, meaning a service could be five minutes late and still considered on time.

The latest data, released last week, shows in March the Bendigo line was at  82.9 per cent punctuality and 97.9 per cent reliability.

Related: Bendigo line ‘down the pecking order’

Reliability is judged on how often a planned service runs and V/Line sets a target of 96 per cent for all its services.

V/Line chief executive officer James Pinder said the focus was on continued improvements over the coming months.

“Now that we’re heading into the cooler weather, we want to be seeing continued improvements with performance so that will be a focus going forward,” he said.

The main reasons for delays to Bendigo line services last month were train faults and trains stopping at stations longer than scheduled.

Mr Pinder said detailed planning work was continuing on the $91 million upgrades and improvements package for the Bendigo line.

He said the Bendigo line upgrade will enable faster services for Echuca and more frequent services between Bendigo and Epsom and Eaglehawk.

Public Transport Users Association regional spokesman Paul Westcott said the single track north of Kyneton and sharing lines with metropolitan trains were reasons for the delays.

Bendigo was reduced to a single track north of Kyneton in the mid 2000s as part of the regional fast rail project, he said, and while some lower-speed crossing loops were retained, no upgrades have been made, making the track prone to “unreliability”.

The state government is working on a $30 million preliminary business case with the Commonwealth which is considering how the recently-announced  airport rail link could incorporate regional rail lines, particularly Bendigo, given it runs through Sunbury.