The Parish Council’s powers to install village gates, speed activated road signs and other road safety measures comes from:
Highways Act 1980
Section 274A: Contributions by parish or community councils.
A parish council or community council may contribute towards any expenses incurred or to be incurred by a highway authority in constructing, removing or maintaining—
(a) traffic calming works, or
(b) other works (including signs or lighting) required in connection with traffic calming works,
if, in the opinion of the council, the expenditure is or will be of benefit to their area.