1	Median Barriers Chapter 6 AASHTO Roadside Design Guide
2	OVERVIEW Warrants Median Barrier Selection Median Barrier Location (placement within median)
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4	Warrants FHWA memorandum to field offices NCHRP Median Barrier Warrant Study AASHTO Technical Committee for Roadside Safety (Roadside Design Guide)
5	Initial Survey Findings… Requests must be specific! FARS data not reliable source for cross-over crashes Many state DOTs unable to identify true cross-over crashes or to correlate crash locations with median width/characteristics Revising warrants upwards likely to reduce cross median crashes in several states
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13	Current Status
14	Median Barrier Systems 3-Strand Cable (generic & high tension) W-Beam (weak post) Box-Beam W-Beam (strong post) w/rubrail Thrie Beam Modified Thrie Beam Concrete Safety Shapes
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16	3 strand cable system
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26	NJ Concrete Barrier
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28	42 inch safety shape
29	Constant slope barriers
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31	Median Barrier Location
32	Figure 6.11
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41	What we know…. Many cross-median crashes occur on medians over 30 feet wide Median encroachments are likely to increase with higher traffic volumes Cross-over crashes are severe Median barriers can significantly reduce cross over crashes Barrier selection and placement are critical for optimal performance
42	What we don’t know What median width/ADT combinations result in cost-effective warrants? How should crash history be considered? How will cable, metal-beam or concrete median barriers perform when struck by a vehicle coming UP a slope into the barrier? When will new warrants be adopted by AASHTO?