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A couple of items have came up since the last time that I had questions for you.  I have looked in the Q&A to see if there was something similar but did not have any luck.  I have two questions that I would appreciate your thoughts and they are as follows:

1. South Dakota uses guardrail delineators that attached to the wood blockouts and the problem arises when there is a bridge with guardrail less than 200 feet in length.  We require a minimum of 4 delineators with the first one being attached to the post/blockout nearest to the bridge and the others spaced at one third of the length of the guardrail.  Where the problem arises is that on occasion, one or two of the delineators are ending up in the end terminal section of the layout where the blockouts are composite type material.  Can the delineators be attached to these composite type blockouts according to our below detail?


2. We have some historic bridges in the Black Hills and they want to maintain that look.  There is a project coming in the near future where the Area Office has requested the installation of weathering steel guardrail and this bridge is located on a NHS route so it will be updated to MGS.  Is there weathering steel guardrail or something similar that would be approved for use in these situations?  I found a past project where weathering steel was used for the guardrail and the end terminals were stained/painted to match.  I have looked at some guardrail manufacturer websites and could not find anything on weathering steel guardrail. 

I appreciate your time on these matters and realize you are busy with other items.

Responses below.

1. I don’t see any issue with attachment of reflectors in the terminal region. However, I can’t comment on if the reflector attachment will affect the structure of the composite blockouts. For a solid wood block, there is little concern for ¼” lag bolts. Composite blocks have different structures and may be hollow with thin sidewalls or have some kind of internal structure. As we don’t design those systems, I don’t know if the lag bolts would affect the structure or not. My general feeling is that it would not likely be an issue, but you should probably contact the blockout manufacturer to find out for certain.
2. We are not proponents of weathering steel. Our experience and several studies have indicated that weathering steels are very susceptible to corrosion and loss of integrity, especially at rail splice locations. An example is shown in the attached research from CALTRANS. FHWA also has a memo out warning about potential corrosion concerns. Some states, like Washington DOT, have moved to staining or powder coating the galvanized rail – see attached memo. This is likely a better solution.

Let me know if you need anything else.