Analysis of current law in respect of metric signs

The analysis given below reflects UKMA's current understanding of the law in relation to signage and the legal constraints on the use of metric units. 

Status of UKMA

  1. UKMA is a voluntary organisation which is not in a position to give authoritative legal advice, and authorities will obviously need to obtain their own legal advice. No liability can be accepted for the views expressed below. However, our understanding of the position is as follows.

The Town and Country Planning (Control of Advertisement) (England) Regulations 2007
(SI 2007 No. 783) (TCPCAR)

  1. Section 220 of the Town and Country Planning Act 1990 authorises the Secretary of State to make regulations for the control of advertisements "in the interests of amenity and public safety". These are the Town and Country Planning (Control of Advertisement) (England) Regulations 2007 (TCPCAR) (SI 2007 No. 783), as amended.
  2. Under Section 336 (1) of the 1990 Act (as amended by Section 24 of the Planning and Compensation Act 1991), an advertisement is defined as "any word, letter, model, sign , placard, board, notice, awning, blind, device or representation, whether illuminated or not, in the nature of, and employed wholly or partly for the purposes of advertisement, announcement or direction ." (our italics). Thus, it is clear that a road or footpath sign is an advertisement within the meaning of the 1990 Act.
  3. Regulation 1 (3) of the TCPCAR provides that the types of advertisement listed in Schedule 1 of the Regulations do not require consent and are thus exempt from control. Class G of Schedule 1 is "a traffic sign", and this is further defined as "a traffic sign as defined in Section 64(1) of the Road Traffic Regulation Act 1984".
  4. This means that a sign is exempt from control if it complies with the definition contained in the Road Traffic Regulation Act 1984 (RTRA). From this it can be inferred that a sign which does not comply with that Act requires consent - either "deemed" (under Part II of the Regulations) or "express" (under Part III).
  5. As noted above (paragraph 2), advertisement control can only be exercised "in the interests of amenity and public safety". This advice is repeated in the National Planning Policy Framework (2012), which states "Advertisements should be subject to control only in the interests of amenity and public safety, taking account of cumulative impacts" (paragraph 67).  It is highly improbable that a distance sign in metres or kilometres could reasonably be argued to pose a risk to public safety.

The Road Traffic Regulation Act 1984

  1. Section 64(1) of the Road Traffic Regulation Act 1984 defines a "traffic sign" as "any object or device (whether fixed or portable) for conveying, to traffic on roads or any specified class of traffic, warnings, information, requirements, restrictions or prohibitions of any description -
    (a) specified by regulations made by the Ministers acting jointly, or
    (b) authorised by the Secretary of State,
    and any line or mark on a road for so conveying such warnings, information, requirements, restrictions or prohibitions."

The wording of this definition appears to mean that any purported traffic sign which does not comply with the regulations or which is not authorised by the Secretary of State is not in fact a "traffic sign" within the meaning of the Act

  1. Section 64(4) of the Act then goes on to provide that, subject to minor exceptions, a traffic sign may only be placed on or near a road if it complies with directions contained in the TSRGD.

However, this provision will presumably not apply to signs which are not "traffic signs" within the meaning of the Act

  1. Section 65 of the Act empowers highway authorities to place traffic signs on or near a road provided that such signs comply with directions which the Secretary of State may give.
  2. Section 69 of the Act empowers highway authorities to require owners or occupiers of land to remove any "object or device (whether fixed or portable) for the guidance or direction of persons using the roads."

However, it should be noted that this is a discretionary power - not a duty. An authority might consider itself justified in taking no action concerning signs which give helpful information and pose no safety risk.  The Act does not authorise third parties to remove non-compliant signs.

The Traffic Signs Regulations and General Directions 2016
(TSRGD) (SI 2016, No 362) (as amended)

  1. The TSRGD specifies and describes signs which are authorised for the purposes of Section 64(1) of the RTRA. These Regulations do not explicitly authorise or prohibit imperial or metric units in principle. However, the majority of the units authorised are in practice imperial - with some exceptions in the case of height, width and length signs for vehicles or bridges, etc, where dual units (metric and imperial) are required. There is no explicit ban on the use of metric units.

General conclusions

  1. Our conclusion from the above analysis is that authorities, contractors and others who wish to erect or maintain metric signs may be able to do so provided that they obtain consent under the TCPCAR.