The technical term for what is commonly called a pavement in the UK, and a sidewalk in the US.
A footway either forms part of a highway, or runs alongside it, and limits the width of a highway which is carriageway. Section 66 of the Highways Act 1980 places a duty on highway authorities to provide footways in locations where that authority considers a footway necessary and desirable.
Although footways are commonly referred to as 'footpaths', in law footpaths are paths away from the highway, not along them.