What is the world's least-busy railway?

An alternative search for the line less travelled

Mumbai's Chhatrapati Shivaji Terminus is one of the world's busiest train stations (Rex)

World's Busiest Railway 2015, part of the BBC's India season, has shone a welcome light on the mesmerising choreography of India's railways – with a close focus on the high gothic of the Chhatrapati Shivaji Terminus in Mumbai. The station, formerly known as Victoria Terminus, manages to combine miraculously the twin roles of a Unesco World Heritage Site and handling millions of commuters and long-distance travellers.

Yet here at hidden europe it got us thinking: what is the world's least-busy railway? We can't be absolutely certain, but we think we've got a fair number of candidates from Europe alone.

We delight in discovering the exotic in the everyday, but on some international railways there is nothing daily about the service. The cross-border train service from Niedaltdorf, in Germany's Saarland, to Bouzonville in France, operates only on Good Friday each year. The French town has a celebrated Good Friday market, and the otherwise abandoned cross-border rail route is reopened for just one day at Easter to allow special trains to run to Bouzonville – usually five in each direction.

Further east, and considerably harder to reach, is the once-a-year journey from Hajnowka in Poland to the town of Bialowieza (and back). We made the trip in 2011. It's a marvellous journey: the forests, heaths and marshes that straddle the border between Poland and Belarus are one of the continent's last great areas of lowland wilderness. Bialowieska Forest is more than history and more than wildlife. Much more. It is for Poles one of the crucibles of their identity. These border landscapes are the gateway to an imagined Arcadia which helped shape the narratives and images of Polish Romanticism. Whether any train will run on this all-too-rare route in 2016 we do not know.

Meanwhile, a slightly less rare international train from Poland connects Lubawka in Lower Silesia with the Czech town of Trutnov. It is a key cross-border line, but trains run Saturdays and Sundays only in the months of May, June, July and August.

The Czech Republic has many more routes which are used on a limited number of days each year.The line to Vejprty is a wonderful route through the mountains between Bohemia and Saxony, but trains run only on about 15 days each year. In a similar vein, the line from Ivancice to Ostavany is normally open to passenger traffic only on 1 May.

As British travellers know, the UK has plenty of oddly infrequent trains, a result of outdated railway law which makes it less onerous to run a bare minimum of services than go through the rigmarole of officially closing a stretch of track or a station. These are known as "Parliamentary" trains. I once had a surreal phone conversation with National Rail Enquiries about how to get from Teesside Airport (two trains a week, both on Saturday) to Denton in Greater Manchester – served by just one Parliamentary service a week. The recommended itinerary between the two averaged just one kilometre an hour.

Nicky Gardner is co-editor, with Susanne Kries, of "hidden europe" (hiddeneurope.co.uk)