Content and synopsis

Foreword by Lord Kinnock of Bedwellty

Executive summary


  1. Introduction
  2. Background of the “very British mess”
  3. Current position: where are we now?
  4. Why convert roads and signage?
  5. Principles of change
  6. Costs and safety
  7. National changeover plan
  8. Conclusion


  1. Experience of other countries
  2. Legal position on road signage
  3. Costs of amending distance signs


Britain’s road signs are a special case of the confusing muddle of measurement units in use in the UK today. Not only are our road signs themselves a muddle of metric and imperial units, but the retention of imperial units on these very prominent and highly important signs is a major disincentive to people to become familiar with metric units in other walks of life.

This muddle has resulted from the failure of successive British Governments to carry through the policy, announced in 1965, of converting to the metric system as the primary and eventually the only measurement system to be used in the UK. It was originally planned to convert Britain’s road signage and speed limits to metric in 1973 but this plan was shelved and never re-instated.

Meanwhile British industry and education moved on adopting the metric system. The result today is that road signage remains almost exclusively imperial while motor manufacturers, road contractors and map-makers use metric. Even Department for Transport’s (DfT) documents use inconsistent units – for example requiring yards or fractions of a mile for distance signs while giving stopping distances in metres (and feet) in the Highway Code. There is no easy way to calculate fuel consumption with fuel sold in litres and roads marked in miles.

There would be many benefits for Britain completing its conversion of road measurement to metric. Firstly, it will enable the UK at last to enjoy a single system of measurement which is understood and used by everyone for all purposes. Secondly, it would provide drivers with consistent information in one single, easy system of units. Thirdly, mapmakers, surveyors, engineers, motor manufacturers and contractors who build and maintain the UK’s road infrastructure would be more efficient as they would not have to convert their metric measurements to imperial.

Reasons given in the past for not converting from imperial to metric are examined and are shown to be spurious. The costs of conversion are analysed and are shown not to be a serious obstacle to change. Safety issues are examined and experience from other countries (Australia, Canada and the Republic of Ireland) has shown that the changeover can be carried out safely.

UKMA proposes a National Changeover Plan to convert from imperial to metric. A practical, costed plan is outlined which demonstrates that given full and rapid commitment from the Government, the confusing anomaly of imperial road signage could be ended within three to five years.