I know very little about mopeds, preferring a machine propelled by pedal power, but their importance is just registering with me after watching a recent Jonathan Dimbleby programme about positive developments in Africa. The very next day, I was peacefully cycling along a Bradford road when I was passed, at speed, by a queue of ten quad bikes, driven by excited young men. My interest was whetted.

Any documentary film about Africa and south Asia shows bustling street scenes, thronged with traffic, mainly lorries and buses, but with hordes of mopeds and small motorbikes.

Mechanised two-wheeled transport is now of increasing importance in the rapidly-growing urban areas of the developing world, where car ownership is less than three per cent of the adult population compared to more than 50 percent in Europe, and even higher in north America.

It’s not uncommon to have two adults and a child on one moped and it’s a very effective method, particularly where public transport is infrequent or non-existent. China has cornered the market with steeply-rising sales of mopeds that are delivered in a flat pack and assembled on site, at a third of the cost of European models, and it’s expected that the numbers will double in the next decade.

The downside, of course, is that as most mopeds use petrol, they produce CO2 as they buzz along, often close to the emission level of small cars, and there is likely to be an increase in carbon dioxide from this source as mopeds become much more common worldwide.

It is possible to have emission-free electric mopeds and scooters, but at the moment they are more than three times as expensive as the technically-simpler petrol ones, and it would be necessary to make sure that the batteries were recharged using electricity from renewable sources.

While a case can be made for more mopeds in many parts of the world, it is far more difficult to find acceptable reasons for quad bikes on the streets of British cities. Their natural habitat should be restricted to the largest farms, and sheep rearing in hilly areas, where they can often be seen giving a lift to a couple of working dogs.

The Top Gear fixation with speed, motoring technology and flashy style aimed at the impressionable young is a distortion of the value system needed in a mature society facing the threat of inevitable climate change due, in the main, to the uncontrolled use of convenient fossil fuels and the seduction of mechanical bling.

We need to accept that powered transport is just a means of getting from here to there, safely, and has no relationship to our status or self-worth.