Transport-related visitor sites enjoyed a 10 per cent increase in traffic compared to 2 per cent overall.
The Moffat Centre for Travel and Tourism Business Development at Glasgow Caledonian University, which published the figures, attributed their popularity to people seeking “active experiences”.
Attractions benefitting included the Strathspey Railway in Aviemore, which carried a record 70,600 passengers – nearly 22 per cent more than in 2014.
The Falkirk Wheel boat lift was up by almost 18 per cent to a record 605,000 and the Bo’ness and Kinneil Railway recorded an 8 per cent rise to nearly 74,000, which was also its highest total.
The Leadhills and Wanlockhead Railway put on 6 per cent to 2,700 visitors. Elsewhere, Edinburgh Bus Tours attracted 552,000 passengers - 4 per cent more than in 2014.
Moffat Centre director Professor John Lennon said: “Folk want to do activities and have an experience, such as travel on a steam railway or go in a boat trip.
“This area of tourism seems to have momentum.”
Prof Lennon said the Falkirk Wheel, which offers boat trips, had been boosted by the nearby Kelpies and Helix park.
David Fraser, chairman of the Strathspey Railway Charitable Trust, put its own growth down to service and booking improvements last year.
He said: “We introduced fine dining, which has been hugely successful and was booked out for the whole season. Our online booking has also been very successful and now accounts for 85 per cent of tickets sold, which is far ahead of other railways.”
Steve Dunlop, chief executive of Scottish Canals, which runs the Falkirk Wheel, said: “We’re immensely proud the Wheel has enjoyed its busiest 12 months since it first started turning back in 2002.
“The chance to see this iconic feat of engineering in action is still drawing huge numbers of visitors, boosting the economy of the area and helping put Falkirk on tourists’ ‘to-see’ lists the world over.”
A Network Rail spokesman said: “We’re extremely encouraged by the rise in interest in transport attractions.
“They give further credence to our belief that a visitor attraction at the Forth Bridge would be a major draw for visitors to Scotland.”