The new Siemens train rolls through the burbs, resplendent in the latest train company colours.

A middle-aged man chats into his mobile phone about planning permission for a four story storey monolith in a residential area of one story homes, with the voice of experience and reason, rather than that of the outraged NIMBY. He’s not talking loudly, but that whole section of the carriage can hear him, and he’s oblivious to the dagger stares of every little old lady within ten metres.

A well-dressed woman boards. Grace, poise, all signs pointing to a respectable corporate worker, apart from a slightly edgy nose stud.

In the mostly-offside-doorway, a man leans against the bright yellow railing, pondering what he might blog about later, trying to decide if he should change at Richmond for a direct train to Flinders Street (thus avoiding most of the rain on the walk from Parliament, but probably ending up in the subterranean platform 13) and increasingly aware that the particular outfit of clothes he’s chosen that day make him look a little like a crusty old maths teacher. Lucky no leather elbows.

The train’s Next Station display confidently states “Carrum”, thoughout the trip, though Carrum is 20km back. Sometimes they’re accurate. Sometimes they’re a station out. Sometimes, like this time, they’re totally whacked.

Why? This is not the most complex technology in the world. I seem to remember similar devices working okay on the London Underground last time I was there six years ago. And they have huge swathes of track unable to pick up satellite GPS signals to determine their position.

Surely here with most stations aboveground, a combination of GPS and trackside or other locators (with GPS taking priority where applicable) should do the trick?

And don’t think I haven’t noticed the Siemens trains claim Flinders Street when they should say City Loop…