Twitter and Facebook have a social networking rival for Britain's teenagers – the bus!
Free travel means double and single-deckers have become the place to bond with friends, according to a new survey.
Some youngsters have even developed a 'code of honour' for travel. For example, getting on without your bus buddy, or leaving them behind, is regarded as the worst type of social betrayal among 12 to 18-year-olds.
Researchers at the London School of Hygiene and Tropical Medicine and University College London found that group outings are essential for fostering friendships.
Some teenagers will wait several hours just so that they can travel with their friends.
This behaviour is in contrast to adult commuters who will often do anything to avoid contact on public transport.
Dr Anna Goodman from the LSHTM said the study showed that free bus travel has improved the social lives and independence of young people and should continue even in the current economic climate.
She said: "Like Facebook, this is a way of keeping in touch with people who don't live near you and improving your social life.
"Finances are absolutely key to this: it's not a given that young people's travel will be covered by parents, even wealthier ones.
"Equality for everyone is very important and free bus travel helps young people socialise and feel part of London. It means groups of friends can travel together without anyone being left out."