View Q&A

One of our attenuators (old unit) at the RR bridge pier had been hit, as shown on the attached pictures. Location: https://maps.app.goo.gl/Dj8SNRyk7Vo9FB4B8.

It is a 30-mph route, one way street, and there is curb at the piers. The piers on the sidewalks have a similar arrangement and do not have any protection installed. Additionally, every column (in the center and sidewalk) is spaced out and could be considered its own hazard.

Could you please provide some recommendation to shield the hazards?

Thank you,

I have some thoughts on your tricky installation. As you noted, the piers are a hazard at the end of the installation as well as along the length on both the sides and the median. Additionally, you are somewhat space restricted.

Here are some thoughts.

1. The best option for this situation is likely to shield the piers on both the side and median sections with some kind of barrier and then installing a crash cushion to shield the ends of the barrier systems and pier. See schematic below for an example.
2. There may be a couple of barrier options. We have a TL-2 concrete parapets that could be applied. Alternatively, due to the reduced space, one could apply a thrie beam bridge rail type system mounted on top of the curb with the posts spaced between the piers. Examples of these barriers are linked below.
   1. Low-height parapet

                                                                              i.        https://mwrsf.unl.edu/researchhub/files/Report361/TRP-03-397-19.pdf

                                                                            ii.        https://mwrsf.unl.edu/researchhub/files/Report475/TRP-03-470-23.pdf

                                                                          iii.       https://mwrsf.unl.edu/researchhub/files/Report83/TRP-03-109-02.pdf

2. 2. Thrie Beam Bridge Rail

                                                                              i.        https://mwrsf.unl.edu/researchhub/files/Report445/TRP-03-448-21.pdf

3. If space does no allow for that type of installation, the best one may be able to do is limit speed as much as possible to minimize the potential hazard posed by the piers and shield the ends with a crash cushion as you have done previously.

Let me know if you have any questions or wish to discuss further.

Thanks!