If you thought that the underground was a dark web of tunnels for crowded trains transporting passengers in cold anonymity, think again. It is a place of romance and excitement, of contact and communication — a vibrant, subterranean world of life-defining exchanges.

Love is flourishing on the Parisian Métro, according to a study by the Paris Transport Authority — and researchers believe that the same is probably true on other underground systems, including London's.

The survey found that the majority of internet messages posted by Parisians seeking a beautiful stranger whose path they had crossed stemmed from a look, a smile or a conversation on the Tube.

Encounters in museums, parks, cafés or on the street were far less likely to produce passion.

A second study commissioned by transport chiefs in Paris showed that 12 per cent of Parisians had struck up a lasting relationship, as friends or lovers, with someone whom they met for the first time on the underground.

Transport executives now envisage platform cafés where the flirtatious can continue their conversations, or mobile web services to enable passengers to search for a soulmate.

“The Métro is not the emotional desert, the social vacuum that we sometimes believe it to be,” Georges Amar, the head of the authority's conception and innovation department, said. It was an environment that induced “love at first sight”, he claimed.

“The person who has never seen the women (or man) of their life disappear from a carriage as the doors close can never have taken the Métro. I don't see why it wouldn't be the same in London,” Mr Amar told The Times.

The comments were made after the publication of L'Amour Mobile, a Paris Transport Authority survey of 600 internet messages.

“The Métro is without doubt the foremost producer of urban tales about falling in love,” Frank Beau, the author of the study, wrote.

More than 80 per cent of the messages were from underground passengers, typically aged between 18 and 25, and divided almost equally between men and women. They were often reading books or listening to iPods — activities which, far from isolating travellers, seem to unite them.

Romantic tension ran high because of the physical proximity of passengers, according to Mr Beau.

In such circumstances the slightest contact — a glance, a word, a jacket brushing against your shoulder — becomes an “extraordinary experience”, he said, adding that the folding seats by the doors were the best spot for romantic encounters.

Mr Amar said that the findings of the survey demonstrated that the underground could become a “physical internet” where strangers met, talked and then moved on.

Brief encounters underground

— “It was Monday, January 29. We got on at Bibliothèque. I was reading a book. We looked at each other twice. That's not a lot but it was intense and pleasant. It made me want to see you again”

— “I was eating a baguette and you a nectarine. We smiled at each other. When you got off at Ledru-Rollin station, you turned to smile at me one last time”

— “I flopped down opposite you and glanced at you. Why did I do that? I couldn't take my eyes off you for 20 minutes. I got off at Mouton-Duvernet station. I am kicking myself for not having spoken to you”

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