An Act which sets out the powers and duties of highway authorities. Duties are things that these authorities have to do. Powers are things that the authorities may wish to exert.
This act essentially allows the highway authority to adopt, improve and a control a highway, but makes it responsible to maintain. For those wanting to try a bit of clever engineering, there are powers to build cycle tracks, footways, humps, traffic calming, traffic signs - the list goes on.
From The Ranty Highwayman.
Part V of the Highways Act 1980 has particular relevance for local authorities wishing to make (rapid) changes to highway layouts - for instance, changing the widths of footways and carriageways, constructing cycle tracks, and the use of physical objects to create (or protect) footways, cycleways. The potential of this act is summarised here.
In particular, Section 75 of the Act gives highway authorities the power to vary the width of carriageways and footways, and Section 66 allows the introduction of physical measures that can be used to create (or protect) footways, or cycleways. Section 65 gives the power specifically to create cycle tracks -
...a highway authority may, in or by the side of a highway maintainable at the public expense by them which consists of or comprises a made-up carriageway, construct a cycle track as part of the highway; and they may light any cycle track constructed by them under this section.