The 21,850-population of the islands has an average of 49m (160ft) of road per person, which is more than anywhere else in Britain, according to analysis of figures produced by the UK Department for Transport.
Orkney motorists also enjoy the highest quality roads in Scotland, with nearly 80 per cent in good or acceptable condition, a recent study found.
Scotland has eight of the ten local authority areas with the most road per resident in Britain.
Na h-Eileanan Siar/Western Isles (47.9m/157ft per person) was followed by
Shetland (45m/147ft per person) and Powys in Wales (40.7m/133ft per person).
Edinburgh was lowest at 3m/10ft.
England’s highest entries are Herefordshire (17.7m/58ft per person) and Devon (16.7m/55ft per person).
The area with the smallest amount of road per population in Britain is Tower Hamlets in east London where there is just 0.9m (3ft) per person, not including incoming commuters and delivery drivers.
South east England dominates the bottom of the list, with the lowest 27 entries all in the capital.
This is partly due to a surge in the number of inner London residents. The number of households in this area increased by 78,000 from 2011 to 2015, which is the equivalent of dropping the population of Portsmouth into the centre of the city.
Data from traffic information supplier Inrix shows London is the most congested city in western Europe, costing the economy £6.2 billion last year.
Orkney Islands Council welcomed its accolade, but said there were plenty of better reasons for visiting.
Development and infrastructure committee chair Graham Sinclair said: “As proud as I am of the condition of our roads, they are the very least of the attraction when you consider the culture, world-class festivals, fine food and drink, archaeology and warm island welcome that Orkney has to offer its visitors.”
The RAC Foundation warned that attracting motorists by promoting empty roads could be counterproductive.
Spokesman Philip Gomm said: “Drivers everywhere will be envious of the long open roads that criss-cross much of remote Scotland.
“But ironically, as ever more visitors are attracted to the country just named the most beautiful in the world by the Rough Guide, routes such as the North Coast 500 will become increasingly busy with people looking to ‘get away’ from it all.”
AA president Edmund King said: “These figures show millions of residents in the South East don’t even get three metres of road per person, while those in some rural areas get access to more than ten times that.
“The squeeze on road space, particularly in London, manifests itself from the M25 motorway to the workplace to parking at home.
“AA research has found that even when they get home, 20 per cent of people fret about finding a parking space and up to 13 per cent put off trips to avoid losing the parking spot outside their house.
“In London, that rises to 36 per cent suffering parking paranoia and 24 per cent sometimes abandoning trips.”