There was a time when travelling between New South Wales and Victoria involved going through customs.
When the railway lines first reached the Murray River, from Melbourne to the Victoria border-town of Wodonga in 1873 and from Sydney to the New South Wales side at Albury in 1881, there was no rail bridge: passengers had to transfer by coach.
Even when the rail bridge was completed in 1883, passengers still had to transfer across the platform because the two railways ran to different gauges: the Victoria North Eastern Railway was built to the Irish broad gauge of 5ft 3in, while the New South Wales Great Southern Railway had the British standard gauge of 4ft 8½in.
The fine station at Albury, designed by the NSW Government Railways’ Chief Engineer, John Whitton (1820-1899), is distinguished by its 1,480-foot covered island platform which allowed inter-state passengers to transfer between the gauges – an experience which astonished Mark Twain: “…a singular thing, the oddest thing, the strangest thing, the unaccountable marvel that Australia can show, namely the break of gauge at Albury. Think of the paralysis of intellect that gave that idea birth.”
Though the Commonwealth of Australia was constituted in 1901, oversight of transport policy remained with the individual states, and it took until 1962 to complete a standard-gauge through connection between Melbourne and Sydney.
This produced the anomaly of a twin-track railway between Melbourne and Albury operating as two single lines, one of each gauge.
The remaining broad-gauge track on this route was converted to standard gauge between 2008 and 2011.
The state boundary at Albury-Wodonga is practical, yet appeared to me invisible: the adjacent towns are, after all, both part of the Commonwealth of Australia. A similar conjunction on the border between Canada and the US state of Vermont is more vexatious: http://www.bbc.co.uk/news/magazine-20649024.