Abstract: A highway crash attenuation system having an improved breakaway guardrail post. An improved upper section of Post 1 has an anchor bearing plate with a cooperating stabilizing bolt engaging with the upstream face of the upper post section. The downstream side of the upper post section is provided with split, spaced-apart strut sections which do not obstruct the rear cable pass through notch.

Abstract: A crash attenuation system having an improved, controlled axle release mechanism for a truck trailer mounted attenuator. The axle release mechanism has an axle release insert disposed within an outer bursting tube which is urged downstream by a mandrel resulting in controlled shearing of the fasteners passing through different size elongated slots in the insert and retaining the insert within the bursting tube. Differential shear forces cause the fasteners to shear at different times as the insert is urged downstream resulting in a controlled release of the breakaway axle assembly.

Abstract: A crash attenuation system having an improved, controlled axle release mechanism for a truck trailer mounted attenuator. The axle release mechanism has an axle release insert disposed within an outer bursting tube which is urged downstream by a mandrel resulting in controlled shearing of the fasteners passing through different size elongated slots in the insert and retaining the insert within the bursting tube. Differential shear forces cause the fasteners to shear at different times as the insert is urged downstream resulting in a controlled release of the breakaway axle assembly.

Abstract: A highway crash attenuation system having an improved breakaway guardrail post. An improved upper section of Post 1 has an anchor bearing plate with a cooperating stabilizing bolt engaging with the upstream face of the upper post section. The downstream side of the upper post section is provided with split, spaced-apart strut sections which do not obstruct the rear cable pass through notch.

Abstract: A highway crash attenuation system having W-beam rail elements attached to a plurality of vertical posts. An impact terminal with a feeder chute guides one or more of the W-beam rail elements through the impact terminal. The feeder chute has an impact shield extending along a traffic-facing side of the chute from an upstream-most end to a downstream-most end of the chute closing the traffic-facing side of the chute. The system also has an anchor cable release mechanism for releasing the cable downstream of the first vertical post and an improved first breakaway post. An improved upper section of Post 1 has an anchor bearing plate with a cooperating stabilizing bolt engaging with the upstream face of the upper post section. The downstream side of the upper post section is provided with split, spaced-apart strut sections which do not obstruct the rear cable pass through notch.

Abstract: A highway crash attenuation system having W-beam rail elements attached to a plurality of vertical posts. An impact terminal with a feeder chute guides one or more of the W-beam rail elements through the impact terminal. The feeder chute has an impact shield extending along a traffic-facing side of the chute from an upstream-most end to a downstream-most end of the chute closing the traffic-facing side of the chute. The system also has an anchor cable release mechanism for releasing the cable downstream of the first vertical post and an improved first breakaway post.

Abstract: A highway crash attenuation system having W-beam rail elements attached to a plurality of vertical posts. An impact terminal with a feeder chute guides one or more of the W-beam rail elements through the impact terminal. The feeder chute has an impact shield extending along a traffic-facing side of the chute from an upstream-most end to a downstream-most end of the chute closing the traffic-facing side of the chute. The system also has an anchor cable release mechanism for releasing the cable downstream of the first vertical post and an improved first breakaway post.

Abstract: A highway crash attenuation system having W-beam rail elements attached to a plurality of vertical posts. An impact terminal with a feeder chute guides one or more of the W-beam rail elements through the impact terminal. The feeder chute has an impact shield extending along a traffic-facing side of the chute from an upstream-most end to a downstream-most end of the chute closing the traffic-facing side of the chute. The system also has an anchor cable release mechanism for releasing the cable downstream of the first vertical post and an improved first breakaway post.

Abstract: A highway crash attenuation system having W-beam rail elements attached to a plurality of vertical posts. An impact terminal with a feeder chute guides one or more of the W-beam rail elements through the impact terminal. The feeder chute has an impact shield extending along a traffic-facing side of the chute from an upstream-most end to a downstream-most end of the chute closing the traffic-facing side of the chute. The system also has an anchor cable release mechanism for releasing the cable downstream of the first vertical post and an improved first breakaway post.

Abstract: A highway guardrail terminal having horizontally extending guardrail elements mounted on a plurality of vertical posts. An anchor cable release mechanism having a cable release bracket attached to a W-beam rail element by cable release bolts has an arrangement of tapered slots and elongated openings to quickly release the cable release bracket from the W-beam rail element upon end-on vehicular impact to the terminal. The tapered slots have a geometry which lifts the bracket away from and out of a parallel alignment with the W-beam rail element.

Abstract: A highway guardrail terminal having horizontally extending guardrail elements mounted on a plurality of vertical posts. An anchor cable release mechanism having a cable release bracket attached to a W-beam rail element by cable release bolts has an arrangement of tapered slots and elongated openings to quickly release the cable release bracket from the W-beam rail element upon end-on vehicular impact to the terminal. The tapered slots have a geometry which lifts the bracket away from and out of a parallel alignment with the W-beam rail element.

Abstract: An energy-absorbing post for absorbing the impact energy of an errant vehicle wherein the impact energy is absorbed by out-of-place deformation in the material of the post. Out-of-plane deformation is provided by utilizing a through bolt extending through a splice connection between upper and lower posts sections. Alternatively, out-of-plane deformation is provided by leaving an axial gap on a splice bolts. For terminal applications, a single through-bolt is utilized to allow the upper post section to pivot during end on impacts. Bolt. tear out facilitators, including stress concentrators and pre-buckles, or an angled through-bolt decrease any initially high tear-out forces.

Abstract: A guardrail system having a standard length-of-need section and a terminal end, the terminal end having a high effective flare rate of at least 5:1 is provided with two independent and cooperating cable anchor systems. One of the cable anchor systems is a side impact releasing mechanism which may include a strut connecting a first and a second breakaway post; a strut anchor release affixed at a first end to a first breakaway post and at a second end to the rail element; a strut with a plug weld anchor release; a strut with a shear bolt anchor release; and a strut with an angled plate anchor release.

Abstract: A trailer mounted crash attenuation system has an impact head assembly, a bursting tubular trailer frame member, and a breakaway axle assembly. Upon impact by a vehicle, the head assembly is urged forward bursting the tubular frame of the trailer. As the impact continues, the head assembly contacts an axle accelerator rod which results in the disengagement of the axle, trailer tire, and fenders from the trailer frame member. Impact energy is dissipated by the controlled deceleration of the vehicle as it moves forward through the attenuator system.

Abstract: An energy-absorbing post for absorbing the impact energy of an errant vehicle wherein the impact energy is absorbed by out-of-place deformation in the material of the post. Out-of-plane deformation is provided by utilizing a through bolt extending through a splice connection between upper and lower posts sections. Alternatively, out-of-plane deformation is provided by leaving an axial gap on a splice bolts. For terminal applications, a single through-bolt is utilized to allow the upper post section to pivot during end on impacts. Bolt tear out facilitators, including stress concentrators and pre-buckles, or an angled through-bolt decrease any initially high tear-out forces.

Abstract: An energy-absorbing post for absorbing the impact energy of an errant vehicle wherein the impact energy is absorbed by out-of-place deformation in the material of the post. Out-of-plane deformation is provided by utilizing a through bolt extending through a splice connection between upper and lower posts sections. Alternatively, out-of-plane deformation is provided by leaving an axial gap on a splice bolts. For terminal applications, a single through-bolt is utilized to allow the upper post section to pivot during end on impacts. Bolt tear out facilitators, including stress concentrators and pre-buckles, or an angled through-bolt decrease any initially high tear-out forces.

Abstract: A crash cushion system to envelop at least one bridge pier. The system has two impact heads, one facing one traffic flow direction and the other facing an opposite traffic flow direction. The heads are connected to multi-stage box beam energy absorbers which are in turn connected to a tubular frame structure which envelops the bridge piers. The frame is spaced apart from the face of the pier sufficiently to avoid an impacting vehicle's snagging the frame and contacting the pier structure. Anchorage cables to stiffen and support the sides of the envelope are positioned inside the frame's parallelogram shape.

Abstract: An end splice assembly for a box-beam guardrail and terminal system having a first stage rail element and a second stage rail element. The assembly has two major connecting components. Upper and lower bent plate channels and upper and lower channel splice plates. The channels and plates have side walls which extend laterally to one another when the two rail elements are mated. The channels and plates are fastened together to provide moment strength to the splice within the system.

Abstract: Devices and methods for strengthening the upper portions of the support posts for guardrails and guardrail end treatments against the forces that are imparted to the post during an impact. The upper portions of support posts, particularly the areas proximate the bolt connection, are reinforced. Preferably, a compressive force is applied to those areas as well by the reinforcements. In one embodiment, reinforcement for the upper portion of the post is provided by metal banding that is disposed around the periphery of the post. Alternative exemplary embodiments are also described in which reinforcement to the upper portion of the post is provided by plates that are secured into place on a location proximate the connection bolt and by a metal cap that sits atop the post. In another embodiment, the drilled hole and connection bolt are eliminated.

Abstract: Slot guards for a slotted rail terminals are described having a central section and a pair of wing portions that are angularly disposed with respect to the central portion. The wing portions are folded away from the plane of the central section along lines that are angularly oriented with respect to one another so that the wing portions are wider at one end of the slot guard than at the other end. As a result, the slot guard provides a greater height at one of its ends than at the other end. Apertures for connectors are disposed through each of the wing portions, but not through the central portion. The slot guard preferably provides an asymmetrical aperture pattern and/or conspicuous markings so that the slot guard is not inadvertently installed in a reversed configuration on a guardrail. Methods for forming the slot guard are also described wherein a blank for a slot guard is cut or stamped out of a sheet of metal.