Guardrail is a safety barrier intended to shield motorists from hazards along the Guard Rails Sydney such as steep embankments utility poles and bridge piers whenever possible these hazards should be located outside of the clear zone to eliminate the need for guardrail.
This overhead signs support is located feet from the edge of traveling this is outside of the clear zone therefore guardrail is not needed at this location however due to right-of-way constraints.
It isn’t always possible to locate hazards a safe distance from the guardrail performance is determined through crash testing in a controlled environment in this test the n-terminal absorbs the energy of the impact.
And the guardrail is extruded away from the vehicle when installed correctly guardrail can make our roads safer and lessen the severity of crashes on projects with guardrail the plans will contain a guardrail summary that lists the beginning.
And ending Stations of the guardrail the length of guardrail the warrant points and an end distance this end distance is critical for proper guard rail installation the Guard Rails Sydney standard drawings contain details for installation.
And Guard Rails Sydney will reference them throughout this blog the end distance is defined as the distance from the edge of the nearest traveling to the face of the guardrail the end distance for Guard Rails Sydney is feet in curb.
And gutter facilities guardrails should preferably be placed feet behind the curb rather than at the curb face the foot width provides adequate sight distance for intersecting streets and driveways.
And also allows for sidewalk installation if feet is not available the guardrail should be placed as far away from the face of the curb as the shoulder width will allow now.
Guard rails Sydney will look at some of the basics of guard rail installation a standard guardrail post is feet long with approximately feet inches below the ground
And feet inches above ground during inspection make sure that the guard rail is installed at the proper height foot inches to the center of the rail in a curb section this height is measured from the gutter line or the flow line to the center of rail.
If no curb is installed the guardrail height is measured from the ground level directly in front of the guardrail keep in mind that guardrail will deflect when struck by a vehicle so the offset from the face of the guard rail to the face of the hazard must be verified if the offset distance is feet inches or greater.
Than the standard post spacing is acceptable however in this example the overhead signs support and the signal cabinet are less than feet inches from the face of the rail therefore in order to stiffen the rail.
And reduce the amount of deflection of the rail additional posts must be installed those additional posts must begin at least feet in advance of the hazard Guard rails Sydney also need to make sure that the rail is lapped correctly with respect to the direction of traffic.
This is the correct order of installation with the rail lap properly however this shoe is not mapped correctly given the direction of traffic and must be corrected by the contractor.
The guardrail provisions of the contract will list which guardrail anchor units should be installed all note that the contractor is required to submit an FHWA acceptance letter for each anchor unit as well as certified working drawings from the manufacturer.
This is especially important for impact attenuator units to make sure that they function properly now Guard rails Sydney will talk briefly about median cable guide rail the roadway standard drawings require a minimum deflection area of feet on each side of the guide rail.
And the ditch slopes must be to or flatter please note that this is not an acceptable installation practice cable guide rail cannot be used to protect median hazards like this median bridge bent strong post guardrail must be installed to protect these hazards if you have any questions or concerns about guard rail installation on your projects please contact Guard Rails Sydney.