https://en.wikipedia.org/wiki/Turnpike_trust

The term "turnpike" originates from the similarity of the gate used to control access to the road, to the barriers once used to defend against attack by cavalry (see cheval de frise). The turnpike consisted of a row of pikes or bars, each sharpened at one end, and attached to horizontal members which were secured at one end to an upright pole or axle, which could be rotated to open or close the gate.