turnpike

From Middle English turnpyke (“spiked barrier across a road”), originally used to block access to such a road until toll was paid.

turnpike (plural turnpikes)

1. A frame consisting of two bars crossing each other at right angles and turning on a post or pin, to hinder the passage of animals, but admitting a person to pass between the arms; a turnstile.
   • Ben Jonson

     I move upon my axle like a turnpike.

2. A gate or bar set across a road to stop carriages, animals, and sometimes people, until a toll is paid; a tollgate.
3. (Scotland) A winding stairway.
   • 1830, Sir Walter Scott, History of Scotland in two volumes Vol II, A AND W GALIGNANI, pages 463-464:

     Ramsay stabbed Ruthven accordingly and James lending his assistance they thrust the wounded man down the turnpike by which Ramsay had ascended Voices and steps were now heard advancing upwards and Ramsay knowing the accents called out to sir Thomas Erskine to come up the turnpike stair even to the head Sir Thomas Erskine was accompanied by sir Hugh Harris the king's physician a lame man and unfit for fighting Near the bottom of the turnpike sir Thomas Erskine in his ascent met Ruthven bleeding in the face and neck and called out Fie strike I this is the traitor l on which Alexander Ruthven was run through the body having only breath remaining to say Alas I had no blame of it

4. (military) A beam filled with spikes to obstruct passage; a cheval de frise.
5. A toll road, especially a toll expressway.
   • Daniel Defoe, The History of the Devil

     […] Pope Pelagius, then Bishop of Rome […] thereupon assum'd the Power of opening and shutting Heaven's Gates; and he afterwards setting a Price or Toll upon the Entrance, as we do here at passing a Turn-pike […]

6. (mathematical economics) A trajectory on a finite time interval that satisfies an optimality criterion which is associated with a cost function.
   • 2006, Alexander J. Zaslavski, Turnpike Properties in the Calculus of Variations and Optimal Control, →ISBN:

     In the monograph we discuss a number of results concerning turnpike properties in the calculus of variations and optimal control which were obtained by the author in the last ten years.

turnpike (third-person singular simple present turnpikes, present participle turnpiking, simple past and past participle turnpiked)

1. To form (a road, etc.) in the manner of a turnpike road; into a rounded form, as the path of a road.

   (Can we find and add a quotation of Knowles to this entry?)

turnpike f or m (definite singular turnpika or turnpiken, indefinite plural turnpiker, definite plural turnpikene)

1. A young female gymnast