Traffic Barrier Guidelines
Tracy Borchardt February 2013
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Traffic Barrier Guidelines
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• BWA Process• Usage Guide
Barrier Usage Guide
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Guardrail
Traffic Barrier Terminals
Attenuators
Cable Median Barrier
Concrete Barrier
References
AASHTO Roadside Design Guide,
4th Edition – 2011
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Traversable Element
RDG-Figure 4-1. Breakaway SupportStub Height Measurements
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4 in.
5 ft.
Traversable Element (cont.)
4’
1:6(V:H)
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Traversable Element?
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Traversable Element?
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Traversable Element?
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YES
Warrant Analysis Level
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Flowchart for Analysis of Existing Obstacles
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Proliance Updates – October 2012
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Proliance Updates – October 2012
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Level 0 Table
Analysis Level
then Level 0
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1 2 3
RSAP Guidance – Determination of Alternatives
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Presentation of Barrier Warrant Analysis Checklists
Cover Sheet Table of Contents Disposition Location Plan Data Sheet Calculation Sheet Site Plan
Summary Site Plan Cross Sections Level 0 Table Level 1 Analysis Level 2 Analysis Level 3 Analysis
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Barrier Warrant Amendment Process
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What initiated change to design?
Who initiated change?
Who completes Amendment to
BWA?
In addition to GEC, who reviews BWA
Amendment?
Field changeCM or
ContractorDSE CM
Value Engineering
ProposalContractor
Contractor’s Designer
DSE / CM
Performance Based Design
ContractorContractor’s
DesignerDSE / CM
Gutter and Guardrail
G-3 Modified GutterG-3 Gutter
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Gutter may be constructed in conjunction with guardrail, but is not required solely because of the presence of guardrail and vice versa.
Guardrail shall not be constructed to shield improperly placed gutter or curb.
Guardrail
Barrier Clearance Distance
Barrier Clearance Distance
Obstruction
Measured from back of post to face of obstruction.
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Barrier Clearance Distance
Guardrail System
Post Spacing Desirable BarrierClearance Distance
Minimum BarrierClearance Distance
MGS- 31”Type A
6’- 3” 42” 28”
MGS- 31” Type B
½ Post Spacing
3’- 1 ½” 30” 23”
MGS- 31”Type C
¼ Post Spacing
1-’6 ¾” 24” 14”
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Minimum Barrier Clearance distances are only to be used for Existing Obstacles
Galvanized Steel Plate Beam Guardrail
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Transition to ½ -Post Spacing
Galvanized Steel Plate Beam Guardrail
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Transition to ¼-Post Spacing
Roadside Safety Analysis Program (RSAP)
http://rsap.roadsafellc.com/
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Traffic Barrier Guidelines – Next Steps
Hands-on WorkshopsLate Summer 2013
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Traffic Barrier Guidelines – Next Steps
Construction Manager’s Training
March 22nd and TBD
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