Definition of "linespeed"

(Discussing a speed restriction under an overbridge) Analysis of real-time data from test runs at 125mph showed that operation at linespeed would, indeed, not be sustainable in terms of both contact wire life and pantograph wear. However, 110mph turned out to be acceptable, at a cost of only seven seconds' delay.

2019 October, “Deliveries running late”, in Modern Railways, page 37