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adding wood planks to back of posts

Question
State	WI
Description Text	We have a number of installations of approach transitions to rigid barrier and beam guard where the sidewalk is directly or in close proximity to the back of post. Some of our project teams have installed wood planks at about rail height at the back of post to prevent pedestrians or bikes from snagging into the posts. It may stiffen up the system a little, but I don't see a problem with this so long as it is not within an end terminal. There could also be some additional debris from an impact as well. Many of these locations are 45 mph or less posted speed. I'll try to find a drawing or photos of what they are doing. What is your thoughts?

Question

State

Description Text

We have a number of installations of approach transitions to rigid barrier and beam guard where the sidewalk is directly or in close proximity to the back of post.

Some of our project teams have installed wood planks at about rail height at the back of post to prevent pedestrians or bikes from snagging into the posts.

It may stiffen up the system a little, but I don't see a problem with this so long as it is not within an end terminal.

There could also be some additional debris from an impact as well.

Many of these locations are 45 mph or less posted speed.

I'll try to find a drawing or photos of what they are doing.

What is your thoughts?

System Performance Evaluation

System Types
Approach Guardrail Transitions (AGTs)
Road Closure Gates
Thrie Beam Guardrails

Applications

System Features

Date November 23, 2015
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Attachment wood_rail.jpg

Response
Response (active)	In reviewing this type of installation, there are some concerns about debris and the potential for the backside 2x10 rail to detach from the back of the post during impact and become a hazard to the impacting vehicle. As such, we would likely recommend that this type of installation be evaluated through full-scale crash testing for TL-3 applications. For TL-2 applications like the ones you note above, the concerns with debris and interaction of the rail with impacting vehicles is much lower. Thus, we believe that the timber railing has the potential to be used in lower speed applications without adversely affecting the safety performance of the guardrail or AGT.

Response

Response
(active)

In reviewing this type of installation, there are some concerns about debris and the potential for the backside 2x10 rail to detach from the back of the post during impact and become a hazard to the impacting vehicle.

As such, we would likely recommend that this type of installation be evaluated through full-scale crash testing for TL-3 applications. For TL-2 applications like the ones you note above, the concerns with debris and interaction of the rail with impacting vehicles is much lower. Thus, we believe that the timber railing has the potential to be used in lower speed applications without adversely affecting the safety performance of the guardrail or AGT.

Date November 24, 2015
Previous Views (115) Favorites (0)