Do you know the main reason why it is so difficult to get people out of their cars and on to the greener alternative offered by public transport? Not enough celebrities to gawp at.
Judging by the continuing success of the Daily Mail website, the one thing every great story requires is a celebrity angle, ideally alongside a photo of the celeb nearly naked or looking appallingly unattractive, or preferably both.
So it is with great delight that the Sceptic Tank can report the campaign for greener transport has found its poster girl - Rihanna.
In a publicity stunt of breathtaking simplicity, the pop star travelled to her show at the O2 last night using the tube, apparently even paying for the journey using her own Oyster card.
It turns out the lyrics to her hits Shut Up and Drive and We Ride were not unsubtle metaphors for the kind of general kinkiness the British press revels in pretending to abhor, but were in fact a cleverly subliminal instruction telling people to take advantage of public transport.
According to our sources, Disturbia was also inspired by the unfortunate day Rihanna got trapped for two hours on a broken down Jubilee Line train during rush hour.
Sadly, the green credentials of Rihanna's little Underground jaunt were soiled somewhat by the Sun's revelation that she was picked up by her chauffeur at the end of the journey to be driven the 100 yards between the tube station and the venue. But, you know, it is wrong to expect too much. Baby steps will do to start with.
We only hope the trend catches on and other celebrities follow Rihanna's lead.
The Sceptic Tank would love to see Liz Hurley sandwiched between a screaming toddler and 18-stone builder on a full to bursting District Line train, or Wayne Rooney joining the anti-social kids at the back of the night bus.
Perhaps even Boris Johnson could get involved and cycle all over the city like some crazed political courier service… no, hang on, that one already happens.
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