Timing directional information before a turn: an overground protocol with stop-inclusive progress measurement

Abstract

Directional signs identify a route, but correct branch selection alone does not describe walking before a junction. This article derives a stop-inclusive progress measure and specifies a randomized overground protocol for directional-cue timing. The reference and near-turn gates each span 4 m, at 20–16 m and 6–2 m before fixed turn entry. Gate speed equals distance divided by complete elapsed traversal time, including pauses and reversals. Relative suppression is M = 1 − v_near/v_ref. For constant progress at 1.2 m/s outside one of sixteen 0.25 m bins, a five-second pause gives M = 0.060 under an arithmetic mean of bin speeds and M = 0.600 under complete-gate timing. The arithmetic calculation approaches a 6.25% ceiling for an indefinitely long single-bin pause. The protocol crosses arrow onset at 14 or 7 m before turn entry, 45° or 90° turns, and an upcoming branch either unknown or known before departure. Six traversals per cell yield 48 trials per participant, balanced by direction. A trial score assigns M to completed near gates and a value of one to observed behavioral noncompletion; technical loss remains missing. The primary contrast compares late with early arrow access in unknown-route trials. A timing-by-knowledge contrast, route errors, stop durations, total approach time and head–thorax orientation address distinct aspects of the response. The numerical values evaluate the derived equations. Recruitment and human measurement have not taken place; the protocol requires prospective feasibility and reliability testing.