Changes to Council Directive 85/3/EEC of 19 December 1984 on the weights, dimensions and certain other technical characteristics of certain road vehicles
EU Directive 1985/3
Made by Council Directive 89/461/EEC of 18 July 1989 amending, with a view to fixing certain maximum authorized dimensions for articulated vehicles, Directive 85/3/EEC on the weights, dimensions and certain other technical characteristics of certain road vehicles
From legislation.gov.uk's record of changes, the official one: see it there.