From 'turn' + 'pike' (spiked weapon) — originally a revolving spiked barrier against cavalry, repurposed as a toll gate.
From 'turn' + 'pike' (a sharp pole or weapon). Originally a defensive barrier of revolving spikes placed across a road to stop cavalry. When toll roads appeared in the 17th century, the spiked barrier was repurposed as a gate that only opened when you paid — the weapon became a toll booth. Key roots: turn (English
The New Jersey Turnpike is named after a medieval anti-cavalry weapon. A 'turnpike' was a rotating bar studded with spikes, placed across roads to shred charging horses. When 17th-century entrepreneurs started charging tolls for road use, they repurposed these spike barriers as gates — pay up, or face the spikes. The spikes disappeared, but the name stuck. Every turnpike in America is etymologically threatening to impale you if you don't pay the toll.