A device includes a cone having a cone first end with a flange, the cone extending to a cone second end. A base has a recess to mate with the flange of the cone. The base also has multiple base openings. A ring is shaped to fit on top of the flange and has multiple ring openings to mate with the base openings in a top of the base for releasably coupling the cone to the base.

A hazard triangle includes a triangular shaped body formed of a transparent or semi-transparent material having a thickness and three sides, one of which is a proximal edge. The thickness is substantially less than a length of any of the three sides. An illumination element is configured to emit light into the proximal edge. The emitted light is propagated by the body such that light is emitted from surfaces of the body other than the proximal edge.

Systems and methods are disclosed for reliable detection of oncoming trains and for warning roadway personnel working on the railroad track of the oncoming train. A train detection system includes a wireless communication network further including train detection modules attached to catenary poles along the sides of the railroad track. Each train detection module is equipped with at least two diverse sensors configured to detect trains and other on-track vehicles. Each train detection sensor is simultaneously active and works with other train detection sensors to detect an approaching train and generate train alerts. The train alerts are transmitted wirelessly over the wireless communication network by the train detection modules. The system transmits train alerts to personal alert devices worn by roadway workers. The personal alert device forms an ad-hoc wireless network with the train detection modules.

Visual warning devices that include illuminated rectilinear arachnid structures that break inattentional blindness of observers. The illuminated rectilinear arachnid structures can be mounted on height-adjustable support posts that extend upright from bases. Alternatively the illuminated rectilinear arachnid structures can be provided with magnets to mount the visual warning devices to metal structures. The illuminated rectilinear arachnid structures include pairs of arms that radiate outward from a central head. The arms and central head can be made from a translucent material through which light can be transmitted to illuminate these structures. Lights for illumination can be provided in the heads. The length of the arms can be adjustable, and the arms can be retracted and/or folded into a storage configuration.

Visual warning devices that include illuminated rectilinear arachnid structures that break inattentional blindness of observers. The illuminated rectilinear arachnid structures can be mounted on height-adjustable support posts that extend upright from bases. Alternatively the illuminated rectilinear arachnid structures can be provided with magnets to mount the visual warning devices to metal structures. The illuminated rectilinear arachnid structures include pairs of arms that radiate outward from a central head. The arms and central head can be made from a translucent material through which light can be transmitted to illuminate these structures. Lights for illumination can be provided in the heads. The length of the arms can be adjustable, and the arms can be retracted and/or folded into a storage configuration.

A retaining member is described. The retaining member forms part of a stanchion of a barrier assembly. The retaining member includes an undulating open channel extending completely through the retaining member. The channel is adapted, in use, to retain a flexible elongate member (e.g., a rope or cord) and to restrain movement of the flexible elongate member relative to the retaining member.

A retaining member is described. The retaining member forms part of a stanchion of a barrier assembly. The retaining member includes an undulating open channel extending completely through the retaining member. The channel is adapted, in use, to retain a flexible elongate member (e.g., a rope or cord) and to restrain movement of the flexible elongate member relative to the retaining member.

A safety cone enhancer fits onto a traffic cone or safety cone. The traffic cone or safety cone has a conical member with a first diameter at a base of the conical member and a second diameter at a top of the conical member. The safety cone enhancer has a round or polygonal member with a hole therethrough, the hole having a diameter which is less than the first diameter of the traffic cone and greater than the second diameter of the traffic cone. The safety cone enhancer has a plurality of arms extending from the round or polygonal member; and at least one of: a first hole in said round or polygonal member extending through said polygonal member from the top surface to the bottom surface, said first hole being configured to receive a first signaling device; and a second signaling device which shines light from a surface of the round or polygonal member.

A safety cone enhancer fits onto a traffic cone or safety cone. The traffic cone or safety cone has a conical member with a first diameter at a base of the conical member and a second diameter at a top of the conical member. The safety cone enhancer has a round or polygonal member with a hole therethrough, the hole having a diameter which is less than the first diameter of the traffic cone and greater than the second diameter of the traffic cone. The safety cone enhancer has a plurality of arms extending from the round or polygonal member; and at least one of: a first hole in said round or polygonal member extending through said polygonal member from the top surface to the bottom surface, said first hole being configured to receive a first signaling device; and a second signaling device which shines light from a surface of the round or polygonal member.

Systems and methods for deploying emergency roadside signaling devices are disclosed. In one aspect, system for an autonomous vehicle includes one or more signaling devices configured to visually notify other vehicles when placed on or near a roadway, and an object placing device configured to place the one or more signaling devices. The system further includes a processor and a computer-readable memory in communication with the processor and having stored thereon computer-executable instructions to cause the processor to: determine that the autonomous vehicle has experienced a malfunction, and provide instructions to the object placing device to place the one or more signaling devices on or near the roadway.