Last Night's TV: Watch out – she's got a bee in her bonnet

The Woman Who Stops Traffic, Channel 4; Horizon BBC

"Until such time as they stop us having motor cars, it'll get worse and worse," said a sympathetic man at the beginning of The Woman Who Stops Traffic. He meant well, I think, but his remark perfectly summed up the problem with road congestion. First, there's the assumption that it's a problem "they" can solve but "we" cannot. More significantly, there's the small matter of how "we" react to any move "they" actually make to curb traffic. If you want to peel the thin veneer of civility off the middle-class commuter or school-run parent, just try politely inviting them to leave their cars at home. Kris Murrin did it in Marlow, Buckinghamshire, and several people very nearly became hysterical. A woman in an SUV reacted as if Murrin had launched a violent carjacking attempt, someone else called her a posh bitch and a man from the local chamber of commerce staged a silent walk-out rather than be a party to her unconscionable plan to get residents to leave their cars at home just one day a week. It's called traffic calming, and it's an oxymoron.

To be honest, though, Murrin even grated on me a little, and I was on her side from the very beginning. For a professional problem-solver, she's a bit short on entry-level people skills, adopting a tone of slightly testy jollity when faced with resistance, like a school matron who is going to have one try at being nice before getting cross. There wasn't much in the way of public transport in Marlow, said one local worthy. "You have a fantastic transport system!" Murrin replied briskly. "It's called a pair of legs!" Outside the local school, she questioned people about their transport choices in a manner (I'm not angry, I'm just very, very disappointed) that would have tempted even the most equable driver to park on her foot.

She had logic on her side, though. Many of the parents contributing to the school-gate gridlock every day lived less than a mile away from the school, while the employees at a local firm were using their cars for journeys that could be completed on foot in virtually the same amount of time. And although it initially looked as if Murrin would get nothing but abuse for her efforts, she finally found a few people prepared to abandon their reflexive pessimism and see whether small individual choices might add up to a large social change. School-children were encouraged to join in Marlow's No-Car Day with the dubious carrot of a council-funded bike shed for the school that performed best, and the manager of the local bike shop, with a not entirely disinterested zeal, planned a bicycle parade through the centre of town. And, for at least one day, it was a terrific success. The streets were blissfully quiet and parking spaces were available everywhere you looked. At a stroke, Murrin had ensured that car journeys would be stress-free and considerably faster than walking or going by bike, which is perhaps the biggest problem with traffic calming. The more successful you are, the more tempting it becomes to drive.

A while ago, Horizon caused a flutter in the cosmetics market with a programme that established that a modestly priced supermarket moisturiser significantly outperformed tubs of pixie-dust potion costing hundreds and hundreds of pounds. The investigation was conducted by Professor Lesley Regan, an obstetrician who clearly likes to read the small print on the back of labels and is pretty impatient with quasi-scientific flummery. Last night, she was back on patrol, checking up on the claims you find on supermarket products from anti-bacterial cleansers to pro-biotic yogurt drinks that say they can "help improve digestive transit". Professor Regan said she had no idea what this meant, which is a bit worrying in a trained medical professional, since it's just a way of saying that it will make your pooh go through you faster. She also claimed that she had never been quite sure what "organic" means, at which point you wondered why they would employ an expert to play dumb like this.

But the programme itself made some interesting points. All those excited claims for the anti-cancer properties of pomegranate juice? Funded by a pomegranate-juice manufacturer, based on a study of just 50 men, and with no controls to say whether any other kind of juice, or Coca-Cola for that matter, might have been just as effective. And what about all those premium-priced superfoods? In a thoroughly unscientific experiment conducted by the programme itself, they proved to have no obvious nutritional advantage over humble, speccy, Clark Kent fruits and vegetables. Other bullet points: probiotics are a bit unpredictable in their effects, cholesterol-reducing spreads really work, and if you've visited a hospital recently, you may find you've come home with a free sample of MRSA. There are many products available in your local supermarket to kill it dead, but do everyone a favour and walk there.

t.sutcliffe@independent.co.uk