Millions of vehicles leave and enter the UK each year. The journeys are a mixture of:
- British tourists going on holiday on the Continent or to the Republic or Ireland
- British exports going to European neighbours
- Tourists visiting Britain from neighbouring countries
- Transit traffic between the Republic of Ireland and the Continent
- Imports to Britain from European neighbours.
Today Britain is unique in Europe in using imperial for road signage. This is a nuisance for international travellers. Although Britain is in the European Union, this is not specifically an EU issue as non-EU countries such as Norway and Switzerland use metric road signage.
Britain has made itself needlessly isolated by keeping its roads imperial.
As a result, many journeys to and from the UK require a change of unit in mid-journey.
Britain has direct ferry links to Belgium, Denmark, France, Germany, Iceland, Norway, Spain and Sweden. In the case of the Republic of Ireland, there are not just ferry links but a land frontier with many road crossings. Millions of British tourists and commercial drivers must switch between imperial and metric in mid-journey and adjust to new speed limits in km/h and distance marking in kilometres.
Even drivers crossing into the Republic of Ireland from Northern Ireland need to switch to km/h speed limits and kilometre-based distances.
In the case of tourists coming to Britain from elsewhere in Europe the situation is much worse. The majority will have no background in using imperial, will be unfamiliar with their vehicle dimensions in imperial and will have a speedometer marked only in km/h.
In 2012, London staged a major all-metric event, the Olympic Games. This event attracted millions of foreign tourists – who in turn provided major income to the UK. The attention of the world's media was not only on the athletes taking part but also on the stadia, the transport systems and other infrastructure involved. Britain's image as a modern, progressive and multicultural country was seriously undermined by the use of obsolete imperial signage for both vehicles and pedestrians throughout the Games.