The signposting of the clearance of bridges and other overhead obstructions in the United Kingdom is a mess. Clearances on service station canopies, access to buildings and car parks, motorway construction sites and airside at airports are given in metric units while until 2002 imperial units were used exclusively on road signs. In 2002, the use of metric units alongside imperial units was permitted on height, width and length restriction signs and in 2016 it became mandatory to use both metric and imperial units. It appears that the 2016 requirement to use both units is not properly enforced, possibly to placate voters who are opposed to metrication.
Continue reading “The Bridge Strike Problem”Category: Transport
Metric speed limits – 55 years of dilly-dallying
55 years ago today, the Government announced that,
“Speed limits on Britain’s roads are not to be metricated in 1973, as had been planned by the previous administration, and the Government has no alternative date in mind.”
In the 55 years since that announcement, successive governments have failed to set a new date for the changeover to metric speed limits. We reproduce here an extract from UKMA’s main website:
Continue reading “Metric speed limits – 55 years of dilly-dallying”
Metric speed limits, with a limit of 30 km/h in built-up areas, could reduce annual insurance premiums by £50
Yet another argument in favour of switching to metric road speed limits has emerged since Wales switched the default speed limit in built-up areas from 30 mph to 20 mph two years ago.
Do British road signs display symbols or abbreviations?
According to the Concise Oxford Dictionary, an abbreviation is defined as a “shortened form of a word in which part of the word is written” [rather than the whole word] while a symbol is defined as a “Mark or character taken as the conventional sign of some object or idea or process”. As a result, abbreviations are language-sensitive whereas symbols can be consistent across linguistic boundaries.
Continue reading “Do British road signs display symbols or abbreviations?”DfT excuse for promoting unauthorised imperial signs in the TSM for the last 9 years
When the latest Traffic Signs Regulations and General Directions (TSRGD) came into force in April 2016, imperial-only restriction signs for height, width and length were no longer authorised. However, the Traffic Signs Manual (TSM) that provides guidance to road contractors on signage has not been updated since 2009 and still includes imperial-only restriction signs to this day. Six months ago, I asked my local MP to contact the Secretary of State for Transport to ask why the Department for Transport has been promoting the use of unauthorised imperial-only road signs since 2016. I received a reply from the DfT a few days ago.
Continue reading “DfT excuse for promoting unauthorised imperial signs in the TSM for the last 9 years”Speedometers and Metrication
How are speedometers designed to accommodate the change from mph to km/h? In this article I will examine a variety of techniques and at the end of the article I will propose a 21st Century solution.
Continue reading “Speedometers and Metrication”20 years of metric speed limits in Ireland
Today marks the 20th anniversary of the metrication of speed limits in the Republic of Ireland. 20 January 2005 was the day that all speed limits in Ireland switched from mph to km/h.
Continue reading “20 years of metric speed limits in Ireland”
Does the Traffic Signs Manual promote the illegal use of imperial-only vehicle restriction signs?
Eight years after the Traffic Signs Regulations and General Directions (TSRGD) were updated to require all new vehicle restriction signs to show vehicle width and height restrictions in both metric and imperial units, the Department for Transport’s Traffic Signs Manual (TSM) has still not been fully updated to take account of the fact that new imperial-only vehicle restriction signs are no longer authorised.
Official thinking on dual unit road signs in the 1960’s
HM Government looked at the case for and against the use of dual unit road signs as an intermediate step in the metrication of road signs in the second half of the 1960’s. Three different methods for dual unit sign conversion were evaluated and some technical issues related to dual unit signs were discussed. The findings and illustrations from the National Archive papers are presented here.
Continue reading “Official thinking on dual unit road signs in the 1960’s”Early Metrication on Southern African Railways
During the last decade of the nineteenth century, events in Southern Africa were dominated by the gold rush as adventurers scrambled to exploit the newly discovered in the Johannesburg area. This and the egos of and animosity between the financier and Cape Colony prime minister Cecil John Rhodes and the aging and dour president of the Transvaal Republic Paul Kruger resulted in the Anglo-Boer War of 1899-1902.
Continue reading “Early Metrication on Southern African Railways”
Metric Views 