Effects of delineation signs on driving behavior in expressway tunnel curves

Objective Driving on curved roads presents higher traffic safety risks compared to straight sections. However, existing research has primarily focused on open road curves, with limited studies addressing safety measures for tunnel curves. This study aims to evaluate the effects of curve delineation signs—such as chevrons, horizontal arrow signs (HASs), and retro-reflective arches (RAs)—on driver behavior at tunnel curves.