In this article, Ronnie Cohen passes on information he has recently received from the Department for Transport (DfT).
In April 2017, I received a response to an FOI request that included a document called “170411-Annex A”. This document contains internal DfT correspondence that reveals a lot about DfT thinking on the use of measurement units on vehicle dimension signs.
Some material in Annex A of the DfT reply to my FOI request can be found at
https://metricviews.org.uk/2016/04/an-insight-into-recent-thinking-at-the-dft/. This will not be repeated here.
There was some correspondence about Phillip Hammond’s decision not to phase out imperial-only vehicle dimension signs in 2010 and noting someone’s expressed interest in the imperial units appearing above the metric units on dual-unit vehicle dimension signs.
Reasons for use of Dual Unit Signs
In response to concerns about the cost of placing two signs at each site, the DfT designed a single dual unit sign as an alternative to the existing two prescribed traffic signs. This design would reduce traffic sign clutter and the installation and maintenance costs for local authorities who chose to provide dual unit signing.
For this reason, the Transport Signs Policy Branch asked for an improved design for the discretionary “headroom” warning sign incorporating both imperial and metric units to be included in the Transport Signs, Regulations and General Directions (TSRGD).
Why Metric appears above Imperial on Dual Unit Signs
Here are a few quotes to explain why dual-unit width and height limit signs show the metric units above the imperial units:
“Our earlier advice did not explain that although the proposed dual-unit triangular warning sign is an entirely new sign, there is an existing dual-unit circular regulatory sign, which has been prescribed and widely used around the country since 1994. When the existing sign was designed, a conscious decision was made to place the imperial below the metric legend. The reasons for the decision were purely based on efficient use of sign space to minimise the overall size of the sign whilst maximising legibility, particularly at night. If you look at the sign in Annex A you will see the imperial legend is widest at the top (because of the inches notation) and the metric text is widest at the bottom. The widest parts of each legend were therefore located together in the centre i.e. the widest part of the sign.”
“When designing the new triangular warning sign, it was desirable to place the widest part of the combined legends as low down as possible, where there was greater width. Placing the imperial legend above the metric would require a step up in the standard size of triangular sign to accommodate the size of font and spacing between the legend and the border required for clear legibility. Larger signs mean greater implementation and maintenance costs for local authorities. They can also be more difficult to locate on bridge structures or be unnecessarily visually intrusive in terms of street clutter.”
“A decision to place the imperial legend above the metric would result in larger signs and some inconsistency issues.
Concerns about misunderstood Imperial Units
There was concern about a lack of foreign drivers’ understanding of imperial units: “Bridge strikes continue to cause significant disruptions to the road and rail network and these strikes could cause a potentially major incident. Chapter 4 of the Department’s Traffic Signs Manual recommends that metric heights be shown on roads used frequently by foreign drivers because they are involved in a disproportionate number of the bridge strikes.” What follows are details of prescribed vehicle dimension signs in the TSRGD at the time.
DfT Reaction to Metric Views Articles
Robin Paice’s comment on the “Who should pay for metrication of road signs?” Metric Views article, was forwarded by a DfT civil servant to others on 5 December 2011, whose names were all redacted, with the following remarks:
“The story continues …. Sad to say, I enjoyed the article and the comments to it. Good background stuff for correspondence on this.”
Robin Paice’s email about the “Metric signs on UK roads: your FAQs” Metric Views article, was forwarded by a DfT civil servant to others on 30 January 2012, whose names were all redacted except for one Anthony Boucher, with the following remarks:
“Fyi – well constructed, if fatally flawed. Given the costings we have been provided for signing 80 mphs [sic], the estimate for conversion must now greatly exceed our previous estimates.”
Shift in DfT Policy on Use of Metric
On 10 June 2014, Robert Goodwill MP, the then Parliamentary Under Secretary of State for Transport, emailed Submissions (cc Steve Gooding, John Parkinson, Anthony Boucher), in response to submissions about updated guidance on the prevention of bridge strikes, saying:
“Hi [name redacted],
Many thanks for your submission.
As we discussed today, the feels [sic] it would be beneficial to mandate dual unit signing – firstly for then new generation of young drivers who learn metric in school, and secondly, foreign drivers who may understand metric only.
He is happy for the report to be published however would appreciate if we could look at the above during the TSRGD review.”
An email to Robert Goodwill MP on 14 October 2014 suggests the removal of imperial-only vehicle height or width limits in the next version of TSRGD and that the revised TSRGD no longer prescribes imperial-only signs, so that in future when signs are replaced they must be dual imperial and metric signs. The transport minister Patrick McLoughlin agreed with the recommendations. It took a few days for the government to accept this idea. A previous transport minister Phillip Hammond rejected it a few years ago.
Options for Removal of Imperial-Only Vehicle Dimension Signs
Two options were considered for removing imperial-only vehicle dimension signs:
- Allow imperial only signs to remain in place only until such time that they become life-expired, or replaced during routine maintenance, at which time the dual-unit equivalent must be used.
- The alternative option would be to mandate in TSRGD that only dual-unit signs could be used.
Option 2 was rejected because “it would impose an unfunded burden on local government that would need to be found from DfT budgets, and would force local authorities to replace signs in preference to other planned maintenance work.”. The DfT estimated this cost to be £2 million in 2015-16. The DfT added that “As the removal of imperial-only signs was not included in our recent consultation on TSRGD, there is a risk of that the policy could be challenged by local authorities.”.
The DfT went for option 1 because it is cost-neutral. The DfT said that “We recommend a cost-neutral option that removes the prescribed signs from TSRGD when it is amended. This will allow imperial only signs to remain in place only until such time that they become life-expired, or replaced during routine maintenance, at which time the dual-unit equivalent must be used. This disadvantage of this approach is that it will take time to see the removal of all imperial only signs, but local authorities already have the freedom to replace any signs, and could do so if they have concerns about potential bridge strikes. This option would deliver the policy change, be cost-neutral, and retains the freedom for local authorities to act at greater pace if they have any concerns over any of their existing signs.”
Fear of Media Reaction to Metric Adoption
Another factor that motivated the DfT to go for Option 1 is fear of the hostile reaction of the popular media. On this issue, the DfT said, “While it is expected that any decision to withdraw imperial signs would be welcomed by road users, the loss of imperial-only signs might be viewed by some stakeholders and media as further evidence of the loss of ‘British’ systems. Imposing dual signs on local authorities is unlikely to be well received, with the possibility of negative comments being played out in the media.”. One email with the subject heading of “TSRGD Stakeholder Engagement” reveals that “The change generated some national press interest with articles from the Daily Telegraph and the Daily Mail, both saying that it could lead to further metrification [sic].”
Another quote on this issue stated, “There is a small risk that media could pick up on the fact that we are still allowing the dual unit sign to be used. However, press office will have lines to take explaining that we are giving councils the option of using a dual unit sign or a sign with imperial measurements.”.
That provides an indication of how much our political leaders fear the mass media and do not dare to challenge this mindset. Hence, it is so rare to find any who are willing to make the case for completing the UK’s transition to the metric system.