Why the UK must relaunch and finish metrication

Back in 1965, the UK started its metrication process, with the aim of finishing by 1975. This target has been missed by 34 years and counting, which is a serious embarrassment. Although the UK is officially metric, with all trade, commerce, education, science, and technology solely or primarily in metric, the fact is that metrication in the UK is far from complete.

The failure to finish converting to the SI metric system means that the UK is a land where fuel is bought by the litre, yet many measure fuel economy using miles per gallon. We also see metres and kilometres in athletics and at the gym, yet we still encounter yards and miles on road signs. This is a measurement mess.

We learn primarily metric at school - and I can say my education was almost solely in metric - yet we are not given enough, if any, opportunity to practice it outside of school, college, university, or work. The media do not help the situation either with their usage of imperial, especially the tabloid press and celebrity magazines.

A special case of this measurement mess is on road signs. When I drive, I see signs in miles, yards, feet and inches. None of this I encountered at school, and yet I am forced to cope with these. This is a problem for young people, learner drivers from the UK and abroad, visitors from abroad – especially from the rest of Europe and most of the rest of the world.

Ironically roads and road signs are designed, built, and positioned using metric units and have been for decades, yet the information on the signs themselves are required to be mostly imperial which must be really inconvenient for road contractors as well.

There are dangers to this mess too. The Engineering industry in the UK did not go metric soon enough, and paid the price with its decline, as did the UK automotive industry, which is shown in more detail in this article. The USA, which has also yet to finish going metric, lost a satellite in 1998 because NASA was working in metric, and one of its subcontractors was working in non-metric (US Customary) units.

Another danger comes from mixing up US Customary units with Imperial units (which are not always the same by the way), one instance of this unfortunately happened in 2001 when someone confused US gallons for Imperial gallons (which are different), which eventually caused an accident due to running out of fuel, which could have been avoided by only using litres which are the same everywhere.

This highly confusing mess is also really unfair on the younger generation, who knows what harm this is doing to their numeracy, which is discussed in greater depth here. In fact, a Department for Education study in 2002 found that 29% (almost 1 in 3) of all adults were unable to calculate areas in either metric or imperial. Measurement is an important part of numeracy.

Finishing our metrication programme will have a lot of benefits. A fully metric environment reinforces what people learn, or have learnt at school. This can only help numeracy, even if it is not a panacea in itself.

Another benefit of metrication is that it saves a lot of money in the long term. The construction industry, one of the first industries in the UK to finish metrication, did so back in 1970 and is reaping the benefits of using only the metric system for all purposes, and the construction industry must surely have achieved significant cost savings as a result.

Maintaining only one line of production in metric units helps to lower costs significantly, because only metric goods need to be produced instead of maintaining both metric and imperial production lines.

Metrication also helps in consumer protection as we are able to compare prices transparently and easily, helps safety by eliminating the risk of using two systems or imperial alone (especially the risk of calculation errors), and metrication also helps the UK remain competitive internationally. The international metric system is simply the best, most powerful, and easiest to use measurement system.

It is in the national interest to finish the job. Of course there will be grumbling and groaning beforehand, but after a successful and well managed changeover people will be wondering "What was all the fuss about? And why did it take so long?".