Traffic Signs Regulations and General Directions
The Traffic Signs Regulations and General Directions (commonly abbreviated to TSRGD) is the law that sets out the design and conditions of use of official traffic signs that can be lawfully placed on or near roads in England, Scotland, Wales, and the Isle of Man.
The TSRGD has undergone several major re-issues and each of these has been amended for minor changes many times before the present series was first published in 1965. (Issues before that covered a former traffic signs system dating back to the early twentieth century which has now been superseded – see TSRGD 1964, below.) The amendments usually just introduce one or two new types of sign or a minor change to an existing one. It's worth noting that innovative signs that are not yet authorised by the TSRGD often start to appear on the roads years before they get TSRGD approval, but until they do, the local authority wishing to use the sign must have it individually approved by the Secretary of State for Transport.
This came into force 1965-01-01. This was the legislation that introduced the Britain's all-new traffic signs resulting from the Worboys Committee of 1963.
This 1994 legislation  is now repealed by the 2002 legislation. Amongst the changes from TSRGD 1981 were provisions for optional metric supplementary indications on height-restriction signs.
The current major version (as of May 2011) is TSRGD 2002, SI 2002/3113 (commonly abbreviated to TSRGD). Amongst the changes from TSRGD 1994 were provisions for optional metric supplementary indications on width-restriction signs.
TSRGD Amendment 2008
This is a minor modification to TSRGD 2002, introducing just one new sign, the combined "speed-limit repeater" roundel and "traffic-camera" symbol on a rectangular plate.
TSRGD Amendments 2011
A government consultation document was published on 24 September 2009 with a view to amend the legislation in 2010 to introduce provisions for portable, temporary pedestrian crossings and to mandate the use of dual-units metric and imperial signage for height and width restrictions.
The amendment to provide for portable, temporary pedestrian crossings eventually came into force (entitled "The Traffic Signs (Amendment) Regulations and General Directions 2011") on 9 May 2011.
A second amendment was laid before parliament (entitled "The Traffic Signs (Amendment) (No. 2) Regulations and General Directions 2011") on 20 December 2011. Amongst many minor changes, this amendment provides for an optional dual-units (metric and imperial) height restriction warning triangle, changes to cycleway signage to allow estimated journey times to be flagged and the discontinuation of the misuse of the symbol "T" to mean tonnes on weight limit signs.
The Department for Transport (DfT) announced plans to radically overhaul the central legislation governing traffic sign design and use, with a revised version of the law planned for March 2015, with the public consultation of the document taking place from 1 May - 12 June 2014. 
- Highways Act 1980
- Highway Code
- Road Traffic Regulation Act 1984
- Vienna Convention on Road Signs and Signals
- "Statutory Instrument 1994 No. 1519; The Traffic Signs Regulations and General Directions 1994". Controller of HMSO. 12 August 1994. Retrieved 2011-06-01.
- "Statutory Instrument 2002 No. 3113; The Traffic Signs Regulations and General Directions 2002". Controller of HMSO. 16 December 2002.
- "The Traffic Signs (Amendment) Regulations and General Directions 2008". The Stationery Office. 15 September 2008. Retrieved 2011-06-02.
- "Consultation document on the Traffic Signs (Amendment) Regulations and General Directions 2010 and the Traffic Signs (Temporary Obstruction) Regulations 2010". Department for Transport. 29 September 2009. Retrieved 2011-01-04.
- "The Traffic Signs (Amendment) Regulations and General Directions 2011". The Stationery Office. 9 May 2011. Retrieved 2011-05-31.
- "The Traffic Signs (Amendment) (No. 2) Regulations and General Directions 2011". The Stationery Office. 20 Dec 2011. Retrieved 2012-01-09.
- "Traffic sign legislation set for 'radical' overhaul". Transport-Network.co.uk. 16 April 2013. Retrieved 2014-01-18.
- "Traffic Signs Regulations and General Directions 2015". gov.uk. 1 May 2014. Retrieved 2014-09-02.
- The Traffic Signs Regulations and General Directions 2002 (SI 2002/3113) (PDF version)
- TSRGD Online Web-app (unofffical mirror site)