So why does the proportion of children driven to school keep on rising? In 1986, it was 16 per cent, by 1996, it was 27 per cent - now it's well over 30 per cent. Is it laziness? Or are parents rightly concerned about their children's safety? And what can schools do about it? Changing attitudes and breaking habits isn't easy, but with the right measures and plenty of persistence, it is possible.
First steps to change
Look at what goes on when pedestrians, cyclists and drivers converge at school minutes before the bell. Your local authority could help with ideas on parking restrictions, 20mph speed limits, traffic calming measures and more crossing points. And the police will give advice on the best way to ensure parents respect any restrictions you put in place. In north Bristol, for example, teachers record car registration numbers of offenders, and the police send out a warning letter.
Safe Routes to School is a national initiative promoted by Sustrans (see Resources), a charity working for sustainable transport, to encourage schools and councils to create more footpaths and cycle routes. First, find out where pupils travel from, how they travel and what routes they take.
Then approach your local council with proposals on how to make those routes safer. That can mean widening footways, cutting back trees or improving lighting. Or it might be possible to create new paths and cycle routes away from the roads. Think about stationing adults at busy crossing points, or at places where children feel vulnerable.
Out on your own
You can also take steps independently. For example, Waingel's Copse school, Wokingham, holds back cars on the school's premises for 10 minutes at the end of school, until all cyclists and pedestrians have left. This means parents who insist on driving on to the school grounds have to be prepared to wait. Other schools go further and set up exclusion zones, asking parents to park at least 500 metres away and walk to the gates. A compromise may be to establish at least one traffic-free entrance. Or you could have enough lockers to ensure no pupil has to carry a heavy bag, so they don't need to be dropped off at the gate. A practical uniform, including trousers for girls, could make cycling easier.
Try to get staff to lead by example. The independent Royal school in the London borough of Camden pays teachers who cycle to work 10p a mile expenses, while those who come by public transport get pound;300 a year towards the cost of a season ticket.
Why it's not clever to take the car
Most car journeys to school are under two miles - precisely the kind of trip environmental groups try to discourage. "Short journeys are avoidable," says a Sustrans spokesperson. "They also cause a disproportionate amount of pollution because catalytic converters take time to warm up." Not only does taking the car cause pollution, it also exposes you to it. Studies show that in slow traffic, pedestrians inhale two-thirds less fumes than car passengers. And parents ditching the car for the school run could save pound;300 a year.
But the main benefit is exercise. Even a short walk has health benefits, and children each make around 4,000 journeys to and from school in the course of their education. Many teachers believe children who walk to school are more alert and work more efficiently than those who arrive by car. "If you walk or cycle you engage with your surroundings and take important decisions, such as when to cross the road," says Roger Mackett, professor of transport studies at University College London, whose research team is investigating the effects of walking to school on brain power. "No one's suggesting walking is the key to exam success, but it may be that some cognitive skills develop more quickly."
Fifty-four per cent of primary children already walk to school. With a few yellow jackets and some adult volunteers you can help boost this figure by forming a "walking bus".
Several hundred walking buses - and at least a dozen or so "cycle trains" - already take children to primary schools. The idea is simple: adult volunteers walk along a fixed route to school. Pupils wait at designated "stops" where they can "board the bus". A successful walking bus requires dedicated volunteers, and, just like a real bus, it will be well used only if it's punctual and reliable. You need at least two adults: a "driver" at the front, a "conductor" at the back. Some walking buses have a trolley for bags, so you might want another adult to help push.
Local road safety officers will provide training and advice on safe routes, and can arrange for volunteers to be covered by public liability insurance.
Starting a walking bus is easy; keeping it going can be difficult. If enthusiasm starts to wane, try a gimmick such as "walking miles" vouchers for the tuck shop, or a map charting the progress the walking bus would be making from Land's End to John O'Groats.
And don't worry if passengers desert the bus as they grow more independent.
The UCL researchers have found that children who use a walking bus, even for a short time, are likely to continue walking to school as they get older.
The future's yellow
Local education authorities must provide free buses for children under eight who live more than two miles from school (a small percentage) and for eight to 16-year-olds who live more than three miles away. But they don't have to be smoke-belching, bone-jarring beasts. Transport company First has adopted the American idea of the yellow bus. The United States boasts 450,000 buses delivering 23.5 million children to school each day. The UK fleet currently consists of just 20 vehicles - in west Yorkshire and Surrey, for example - but they're making a stir. "The interest has been huge," says Martin Helm of First. "These are brand new, hi-tech and imported from the States at a cost of around pound;80,000 each. It's about image."
Magna Carta secondary school, in Surrey, has two yellow buses. "But we could use six, or even eight," says head Philip Roe. He agrees the buses have a positive image - "very cool and trendy" - but says it's the efficiency of the system that has made the difference. "The route is tailored to the needs of pupils. No one has to walk more than 300 metres to a stop. The drivers are parents, and the children get the same driver each day. It's reassuring for everyone concerned." First bought the buses, but running costs are met through parental contributions (no more than pound;1 a day), LEA funding and local business partnership funding . The drivers get training and are paid, and the school can use the buses during the day for trips and outings.
Four wheels bad, two wheels good
In Denmark, 60 per cent of children cycle to school. In the UK, it's less than 1 per cent. Two key factors are vital if you want to encourage pupils to cycle to school: dedicated cycle paths and secure storage facilities.
Kesgrave high school in Suffolk has worked with its local council to develop a network of traffic-free routes to local housing estates. Pupils can cycle from up to five miles away without having to use a main road. The result? Between 700 and 1,000 of the 1,500 pupils arrive by bike each day.
It's important to have a designated storage area; it must be convenient, secure and large enough to ensure everyone gets a parking spot. At Burnholme community college in York, the "bike shed" is an undercover cycle park opening on to the cycle path. It has security lighting, CCTV and magnetic time locks activated from reception - all at a cost of pound;40,000. But even fixing up some basic cycle stands will send out the right message.
Some schools ban children from cycling to school for fear they will be held responsible for any accidents on the way. But the law states that schools do not owe a duty of care to children making their own way to school. In any case, get parents to fill in a permission slip, and make it clear that you won't be liable for any damage to cycles on the school premises.
Why do we still use the car?
The school run is no fun for anyone. Surveys published last year by Brunel University and the Department for Transport found 80 per cent of children would like to walk to school because it's healthier and more sociable. And 65 per cent of parents who taxi their children to school would prefer not to - they find it stressful and intrusive. So why does the school run flourish?
Because parents worry about safety. Every year around 4,000 child pedestrians are seriously injured by cars. That's four times the number who are seriously injured while in cars. But this does not mean driving is safer than walking. For example, evidence suggests that children who walk regularly are less likely to be involved in an accident, because they develop more traffic sense than those who spend their lives cocooned inside the family hatchback. There's a vicious circle here: parents believe there is too much traffic on the road to allow their children to walk or cycle safely. So they drive. Which creates more traffic, which in turn makes other parents more afraid.
And it's not just traffic that makes parents nervous - they also worry about "stranger danger", bullying and mobile phone theft. Rightly or wrongly, many perceive that their children are at risk if they walk to school unaccompanied. In 1971, 80 per cent of seven and eight-year-olds made their own way to school. Now it is less than 10 per cent.
Is the school run to blame for congestion?
It's a contributing factor. The most commonly quoted statistic is that one in five cars in the morning rush hour is on the school run. In fact, around a third of those journeys would be made anyway, with parents going on to work after dropping off the kids. Ken Livingstone has claimed that "without the development of the school run over the past 20 years, we might not have had the need for a congestion charge". It's true that even a slight reduction in the number of cars can have a big impact on travel times.
Eliminating school traffic would reduce journey times in cities and towns by up to 50 per cent at certain times of the day. On the other hand, it's probably unfair to single out the school run. Almost half of all children still walk to school; if half of all business commuters did the same, congestion would be solved.
If you must keep the cars. . .
Schools with large catchment areas, which may find it difficult to get pupils cycling and walking, can reduce the number of car journeys by encouraging car sharing. In several cases, groups of independent schools have joined together, using the internet or travel consultancies to match families who live close to each other. "All new parents give their postcode," says Ralph Elliott, bursar at the Royal school. "We process the information and suggest car-sharing groups of between five and eight families."
Changing attitudes takes time, perseverance - and paperwork. The Department for Transport is trying to persuade every school to draw up a travel plan.
This may not sound like fun, which explains why only one in 50 schools has one. But a travel plan can be an opportunity to canvass opinions, get parents on board and kick-start a ready-made geography project. "Year 9 students collected and analysed the data," says David Andrews, of Crestwood community school in Eastleigh, Hampshire. "Having a proper document meant the issue and the school got taken seriously. It was easier to get things done."
A travel plan can also help to attract funding, and if you need advice you can apply to the DfT for free "site-specific consultancy". But your first move is to find out exactly how your pupils travel to school; don't assume they'll conform to the national statistics. When Crestwood carried out its initial survey in 2001, it was alarmed to find that 44 per cent of pupils living within a mile arrived by car. Not good. But better than Poisat primary school near Grenoble in France, surely a contender for Europe's laziest school. Its survey found that no pupil lived more than 900 metres from the school, yet three out of four arrived by car.
A brighter, cleaner future?
The research team at UCL is investigating how far the way children travel to school affects their attitude to transport in general. It has discovered, for example, that children who walk to school are less likely to scrounge a lift to the shops or use mum as a taxi service. But does walking to school alter behaviour patterns in the long-term? The answer is probably not. "Even the ones who walk to school, when they reach 17 they just want to jump in a car and drive everywhere," says Professor Mackett.
Main text: Steven Hastings. Pictures: GettyAlamyPhotonica Findlay KemberInsightAndrew Hasson. Additional research: Tracey Thomas
Next week: Thinking skills