The reasons provide an enlightening lesson in what makes technology appropriate, because they show that good designing and making isn't simply about achieving peak performance in ideal conditions but about taking into account the surfaces the vehicle will have to drive on, the parts and fuel available for keeping it on the move, the cost of making it and, of course, the purpose for which it will be used - business or pleasure?
Ironically it is at the Motor Heritage Centre - housing the world's largest collection of what were once the swankiest British cars and situated next door to Rover's secret track for testing new models - that pupils can discover why a bicycle rickshaw can be more suitable technology than even a Land Rover in Third World countries.
For Pounds 2 a head the Motor Heritage Centre, at Geydon, south of Warwick, offers a one-day programme on Third World transport which cuts across technology and geography. The day is the brainchild of archivist Gillian Bardsley, who worked as a lecturer in South Africa and has travelled extensively throughout Africa and Asia.
The visit starts with a slide show which looks at the role of transport in the context of the lives of people in different countries. The children are encouraged to find out what it is like to live in Third World towns and villages, and the daily transport problems that people face, whether walking miles to collect water and firewood or taking a two-day trek on a jam-packed rickety bus to buy furniture and bring it home.
They look at the resources available for transport compared with this country - are there camels on hand, fishermen's boats to be ferried on, can people afford to pay for a car, would they be able to get petrol and spare parts?
But they also look at the technical problems the conditions pose, comparing the normally smooth, durable surfaces of our roads with rural mud tracks that may be impassable in the rains, or pothole-ridden streets in cities.
With this in mind the pupils tour the centre's impressive collection of historical cars, from the red 1910 Austin 7 tourer that looks like a squat version of Chitty Chitty Bang Bang to the 1957 MG record car in which Stirling Moss hit 245 mph and which looks like a flat oval-shaped flying saucer on wheels.
They try to decide which would be good for Third World conditions and which would be bad. As education officer Trevor Lord points out, many, especially the record car, would be totally unsuitable because they are set too low to survive bumpy roads, they are not long-lasting, and their complicated electronics makes them too difficult to maintain.
Most pick out the Land Rover as the ideal vehicle (though the old Morris Oxford is still very popular in India because of its high clearance and the fact that is manufactured locally, so spare parts are no problem) and after lunch they test drive it over tarmac, gravel and an unsurfaced track. But a Land Rover is simply too expensive.
Then they consider a Bangladeshi rickshaw, the appropriateness of its design, and learn about the life of a rickshaw wallah before having a go themselves. It is a hybrid construction, made by joining the body of a hand-held rickshaw to the frame of a man's bike with an extra cross-bar and reinforced fork supports added to provide strength. The front wheel of a mountain bike has been used to improve durability and a three-speed gear system is contained in a hub on the back axle.
Because it is cobbled together it is not ergonomic and the balance is poor, which the pupils soon discover when they realise how much effort is required to drive and control it. The foot rest for passengers is tilted downwards to take into account of the angle it would have been held at when drawn by hand. But, as Gillian Bardsley points out, it uses the cheapest technology available, the spare parts can be kept under the seat and at night the driver can sleep on it.
The session teaches children that people in different contexts have different problems and high technology often is not the best or the cleverest solution. In the Third World, employing ingenuity with scant resources is a valuable skill.
As Gillian Bardsley says: "We are bombarded on TV with pictures of the Third World being poor and in debt but it's not actually that negative. The fact is that people are coping and making a full life in difficult conditions."
* All sessions at the Heritage Motor Centre are run by qualified teachers, tel: 01926 641188. Materials on appropriate technology from Intermediate Technology's education department, tel: 01788 560631