Since then the Coalition has splashed out on a string of projects for the line in the hope it will avoid being skewered in similar style on November 29. Transport Minister Terry Mulder: "Coalition inherited a public transport system with terrible reliability and punctuality." Credit:Michael Clayton-Jones Central to the Frankston line investment has been the $115 million Bayside Rail Project, a mostly technical upgrade so it can accommodate the newer, bigger and quicker X'Trapolis trains, eight of which are being built. A host of other sweeteners have been included in the project – new platform shelters, extra myki readers to reduce queues, CCTV security cameras, rainbow-coloured network status boards modelled on the London Tube, even a fresh coat of paint for station buildings. And the government isn't going to let passengers forget it. On the morning Napthine visits Mordialloc, there are eight billboards spruiking how his party is "Upgrading the Frankston Line", enough to outnumber passengers waiting for the next train. Railway infrastructure isn't sexy. Unlike a freshly laid road, there is no ready-made photo opportunity in a new row of overhead wires or concrete sleepers. But Napthine is doing his best to see that people get the picture.

"What we've done is invested in the basic infrastructure; in the signals, in the sleepers, in the rails to improve punctuality and reliability," the Premier says. Jill Hennessy (second from left) would be transport minister in a Labor government led by Daniel Andrews (centre). "And certainly we've improved punctuality and reliability, for example on the Frankston line it was in the low 60s under Labor and now it's above 90 and that's the sort of result we've delivered by investing in the basic infrastructure," he says. (On this point, the Premier is guilty of gilding the lily. Frankston line punctuality was nudging 70 per cent in 2010, but statistically the line has had the biggest turnaround in performance of any in Melbourne.) The numbers support the Coalition's assertion that it has done a better job at getting the trains to run on time than Labor managed.

Network-wide, train punctuality has risen markedly since Labor's last 12 months in office from a sub-par 85.5 per cent – below the 88 per cent threshold for customer compensation – to 93 per cent, a figure not achieved since the early years of the Bracks government. But the Premier's voice risks being drowned out as he makes this point. There is loud noise from construction workers refurbishing the toilet block on the opposite platform – something the Premier repeatedly refers to as further evidence of improved amenity – and from a heavy stream of water gushing from a blocked drainpipe on the roof of the platform shelter just behind him. The leaking pipe is a vestige of the previous day's fierce electrical storm, a rude reminder to Melburnians that the city's rail network remains a long way shy of world standards. Lightning damaged scores of signals across the network, shutting down some lines and severely delaying travel on all others. The near total meltdown prompted a downcast apology from Mark Wild, the chief executive of Public Transport Victoria, and an admission that the network's frail and ageing signalling system could not cope. Signalling is expensive; a Metro proposal to install new signalling technology on the Dandenong line alone has been costed at $495 million.

Given Melbourne's metropolitan rail network has some 830 kilometres of track, the scale of the investment required to modernise it renders the Frankston line upgrade a drop in a bucket. Public Transport Minister Terry Mulder points to a $1.7 billion spend over the four-year term on nuts-and-bolts maintenance works such as cleaning and replacing track ballast, clearing blocked drains, replacing worn-out sleepers and old sections of rail, signalling cables and overhead wiring. "The Coalition inherited a public transport system with terrible punctuality and reliability," he says. "Through investment in the basics of the rail network that Labor neglected, punctuality has exceeded 90 per cent across the metropolitan network for a record 29 months in a row." But there is another side to how Metro got the trains running on time, in which the government had no involvement but to which it has given tacit approval. Station skipping – the practice of turning a stopping-all-stations service into a limited express train to catch up with the timetable – began in earnest in April 2012, according to paper records kept by train drivers. It is the same month Metro's record unbroken run of 29 months of running the trains on time began.

The unilateral practice has also helped the company to claim more than $17 million in incentive payments in the past 2½ years by meeting its punctuality threshold, while leaving unknown numbers of people stranded on station platforms. The practice has left the Coalition open to charges of having made a devil's pact with Metro so that it can promote its superior performance. The volunteer Public Transport Users Association endorsed the Coalition at the 2010 poll for having a strong set of public transport policies, but in the intervening years its president, Tony Morton, has become one of the government's harshest critics. "Endorsing the Coalition was the right call on the assumption that they would do what was promised," Morton says, "but we didn't foresee the extent to which they would not only break their promises on public transport but basically ditch any big effort to improve it in favour of sinking two decades worth of transport spending into a single road in inner Melbourne." It is no surprise the PTUA feels burned by the government's decision to build the unpromised East West Link toll road while kicking proposed rail extensions to Doncaster and Rowville decades down the track, but Morton also says the Coalition deserves only qualified credit for making more of the trains run on time.

"The punctuality statistics have improved and that's been a technical improvement achieved at least in part by having trains skip stations when they're running late," he says. Public Transport Victoria and Metro say just 0.5 per cent of services are altered to run express on average and only as a last resort to avoid causing more widespread disruption. Labor says it would review the practice but has stopped short of promising to stamp it out. Opposition public transport spokeswoman Jill Hennessy says Labor would address "perverse incentives in our transport contracts" that encourage station skipping. "Why should we reward a train arriving on time if that train has skipped several stations and neglected stranded passengers in order to achieve this? The focus should be on commuters getting a better service, and not reward cutting corners to achieve a performance bonus," she says.

Hennessy – who is on track to be minister in less than a month if the polls hold firm for Labor – argues the government has manipulated the timetables and turned a blind eye to station skipping so it can sell a good news story about how it has fixed the train network. "Labor is concerned that the Napthine government uses 'lies and damned statistics' to trumpet their claims of improvement in our rail network," she says. And as much as the government boasts about improved punctuality, it rarely mentions reliability – the number of scheduled trains that actually run – where it has made no ground since 2010. On average 1 to 2 per cent of trains are cancelled every day, a rate that has held stubbornly firm for 10 years and in real terms adds up to between 500 and 1000 scheduled services a month that do not run. Not everyone who closely follows Victorian politics buys the narrative about how poor service on the Frankston line cost Labor the last election.

Nick Economou, senior lecturer in politics at Monash University, says public transport is largely irrelevant to most Melburnians, with 2011 census data showing just one in four use it to travel to work. "And what are the other 75 per cent thinking about? The car," Economou says. Yet the four seats on the line that swung in 2010 – Bentleigh, Mordialloc, Carrum and Frankston – are so pivotal to the upcoming election neither party could afford to ignore them. "Any party that had an attack of economic rationalism and decided not to do anything about that rail line might as well write off those four seats," Economou says.