Wiktionary
n. A cone-shaped marker, generally made out of plastic or rubber, that is placed on roads or footpaths to temporarily redirect traffic in a safe manner.
Wikipedia
Traffic cones, also called traffic pylons, road cones, highway cones, safety cones, witch's hat, or construction cones, are usually cone-shaped markers that are placed on roads or footpaths to temporarily redirect traffic in a safe manner. They are often used to create separation or merge lanes during road construction projects or automobile accidents, although heavier, more permanent markers or signs are used if the diversion is to stay in place for a long period of time.
Usage examples of "traffic cone".
Hammer, out of breath and perspiring beneath her gray pinstripe suit, thought Ehrhart looked like a traffic cone.
Berman removed a traffic cone from a reserved space, parked the car, and took up his position at the rear door of the gallery.