This document establishes the legal framework and specific modifications for the variation of the Swansea Manchester Trunk Road (A483) and the Shrewsbury Dolgellau Trunk Road (A458) in relation to the Welshpool North South Relief Road project. The text is issued by the government of Great Britain, utilizing statutory authority to amend existing road infrastructure plans. It serves as a formal instrument to authorize changes in the alignment and construction parameters of the specified trunk roads.

This document is a technical legal instrument intended for use by civil engineers, legal professionals, and government planners involved in infrastructure development. Experts categorize this as a primary source document for historical records regarding United Kingdom road network legislation.