The Traffic Signs Regulations (Northern Ireland) 1997 (SR 1997 No. 386).

Statutory Rule 1997 No. 386 was made on 20 August 1997 and came into operation on 1 October 1997. It sets out authorisations by the Department, the control of traffic by signs and light signals, the sizes, colours and types of signs and markings shown in the diagrams, permitted variations of dimensions, and the proportions and form of letters, numerals and symbols.

legislation.gov.uk holds it as a PDF of the rule as made, without the amendments applied. The Department for Infrastructure publishes the original rule together with the amending rules on one page, which is the practical place to assemble the current position.

The DfT Traffic Signs Manual applies across the UK, and Chapter 1 names the Traffic Signs Regulations (Northern Ireland) 1997 as the relevant legislation in Northern Ireland. It warns that diagram numbering occasionally differs, that references to TSRGD Schedules do not apply, that not every road marking in the Manual is in the Northern Ireland Regulations, and that references to directions should be checked with the Department for Infrastructure. Design, meanings and permitted variants are generally similar to Great Britain but can vary.

For a scheme that spans Belfast and a site in Great Britain, do not assume one artwork set covers both. Check each prescribed sign against the right regulations before it goes to manufacture.