Barrier Design

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miloc

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Does anyone knows where L2 (Barrier Offset) comes from?

I came across this problem when reviewing the Roadside Design Guide (Update) Page 5-42

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Hi Ambrug20, thanks for your answer. The errata I have for the RDG erd adition doesn't include that page. The page I have (5-32) has the Figure 5.24 "Approach barrier layout variables" without any numbers, just generic variables (Lc, La, Lr, X, L1, L2, L3, etc) can you please post it or email it to me? thanks.

 
Miloc,

that is exactly what I have. You can see L2 shown on revision page. Can't help more. Good luck for tomorrow

 
Does anyone knows where L2 (Barrier Offset) comes from?

I came across this problem when reviewing the Roadside Design Guide (Update) Page 5-42

miloc,

L2, the Barrier Offset, is the distance from the edge of travel way to the roadside barrier. Unfortunately, there is no nifty chart for determining L2. L2 is to be selected by the design engineer. As a general rule, the barrier should be placed as far from the traveled way as possible but there are many variables that could affect the barrier placement (slope/terrain of the shoulder, the distance from the traveled way to the obstruction L3 (obviously L2 needs to be less than L3), the type and deflection of the selected barrier, etc.). Please see RDG Section 5.6. If the exam were to give you a problem like those in RDG Figs 5.29 - 5.32, they would most likely provide you with L2 (as did these RDG examples). I hope that helps.

 
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