Indoor simulator and field study evaluation of sequential flashing chevron signs on two-lane rural highways
archive: archived pipeline: cataloged verified
Summary
Donnell, Porter, Zlatkovic, Cooper, Li, Strayer, and Lin (FHWA-SA-18-075) evaluated Sequential Dynamic Curve Warning Systems (SDCWS) on rural two-lane highway curves using paired indoor-simulator and field studies. The simulator portion compared flash rates, speed-activation thresholds, and flashing sequences to identify settings that produced the lowest curve-approach speeds; the field deployment then tested the best simulator-derived settings at real horizontal curves. A low flash rate with a sequential lights-toward-driver pattern produced the largest reductions in operating speed approaching the curve, and the field study confirmed simulator-suggested speed reductions in real driving.
Key finding
Sequential flashing chevron signs at a low flash rate with lights moving toward the driver produce the largest curve-approach speed reductions on two-lane rural highways, validated in both simulator and field deployment.
Methodology
Mixed-method FHWA evaluation: indoor driving-simulator factorial study of SDCWS flash rate, activation threshold, and flashing sequence, followed by an in-situ field study at horizontal curves.
Sample size: Exp 1: N=10; Exp 2: N=20
Quality score: 5 / 5