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crash cushion layouts for various situations

Question
State	WI
Description Text	Dear MwRSF, I know that people are probably cringing when I email a question about crash cushions but here I go. I have been digging around trying to figure out how to properly layout crash cushions for point hazards ( e.g. bridge piers, overhead signs...) So I sat down and started drawing some situation out and would like MwRSF to review them. I believe that I will need to add this guidance into our design manual because we are using more and more crash cushions. I've included a couple of PDFs for layouts. "Hazard layouts without concrete transitions.pdf" is a layout for smaller hazards that do not need a concrete transition. I'm using this to set up a size limit (i.e. After a certain size fixed hazard a designer needs to add a concrete transition). "Hazard layouts with concrete transitions.pdf" is a set of drawings showing how to layout a hazard relative to concrete transition section. This PDF also has layouts for median and side of the road. "Roadside layout steps.pdf" is showing the process of layout driveway curb limits for a roadside barrier installation. I know I asked a similar question about what angles to use. I believe that MwRSF indicated that a flatter approach angle on the nose of the crash cushion should be used. The problem I have with using a flatter angle is that in opens the median up for u turns and could cause drainage issues at the roadside. If MwRSF could give review and provide comments it would be appreciated.

Question

State

Description Text

Dear MwRSF, I know that people are probably cringing when I email a question about crash cushions but here I go. I have been digging around trying to figure out how to properly layout crash cushions for point hazards ( e.g. bridge piers, overhead signs...) So I sat down and started drawing some situation out and would like MwRSF to review them. I believe that I will need to add this guidance into our design manual because we are using more and more crash cushions. I've included a couple of PDFs for layouts. "Hazard layouts without concrete transitions.pdf" is a layout for smaller hazards that do not need a concrete transition. I'm using this to set up a size limit (i.e. After a certain size fixed hazard a designer needs to add a concrete transition). "Hazard layouts with concrete transitions.pdf" is a set of drawings showing how to layout a hazard relative to concrete transition section. This PDF also has layouts for median and side of the road. "Roadside layout steps.pdf" is showing the process of layout driveway curb limits for a roadside barrier installation. I know I asked a similar question about what angles to use. I believe that MwRSF indicated that a flatter approach angle on the nose of the crash cushion should be used. The problem I have with using a flatter angle is that in opens the median up for u turns and could cause drainage issues at the roadside. If MwRSF could give review and provide comments it would be appreciated.

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Date January 23, 2013
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Attachment hazard layouts with concrete transition.pdf Attachment hazard layouts without concrete transition.pdf Attachment layouts for wider hazards with concrete transition.pdf Attachment roadside layout steps.pdf

Response
Response (active)	There are many separate issues that are raised here involving the proper installation of crash cushions across a wide variety of installations. The scope of this inquiry is likely outside what can be answered in this forum. In order to better address this issue, a problem statement was submitted by WisDOT for the 2013 Midwest Pooled Fund meeting.

Response

Response
(active)

There are many separate issues that are raised here involving the proper installation of crash cushions across a wide variety of installations. The scope of this inquiry is likely outside what can be answered in this forum.

In order to better address this issue, a problem statement was submitted by WisDOT for the 2013 Midwest Pooled Fund meeting.

Date May 10, 2013
Previous Views (49) Favorites (0)