New figures published this week show punctuality on the Milngavie rail line has improved for the second consecutive period, says Scotrail.
But local Green MSP Ross Greer, who has been campaigning for a better local rail service, said the “marginal improvements” were “not good enough.”
Scotrail said changes to the timetable from December 9 last year have resulted in more on-time departures from Milngavie.
Mr Greer said: “Timetable changes have definitely improved performance on the line, it would be churlish not to welcome that. But he added: “Have they made any more difference other than the fact the weather in December was better than it was the previous year?
“The Westerton to Milngavie line is still one of the worst in Scotland, with little over one in four trains on time. Marginal improvements are not good enough.
“This line needs the transformative difference a second track would make, as independent studies have shown.
“Until this is done, passengers will still have to wait for late-running trains to come the other way through the single track.
“Any residents who agree should sign our petition at greens.scot/milngavieredual.”
A Scotrail spokesperson said that across Scotland, 84.2 per cent of ScotRail trains are meeting the rail industry standard public performance measure and “significant improvements” had been made, including at Milngavie.
Alex Hynes of ScotRail Alliance said: “This has been a challenging time.
“While we know performance has not been good enough, it is encouraging to see our punctuality continuing to improve.”