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TO: K. N. Kirker/Y. A. Mhatre/R. T. Shaefer/J. VanLund
FROM: Chuck Ruth
DATE: December 1, 1995
SUBJECT: Traffic Barrier Details

I was contacted by the electrical inspection office in the Northwest Region today regarding some of our detailing practices on bridge traffic barriers. The Northwest Region had some good suggestions for our consideration as follows:

1.  Junction Boxes in Traffic Barriers

The junction box should be 18"X8"X8". The 8" depth is required so that the conduit extending from the junction box miss the reinforcing in the face of the traffic barrier. The call-out for the junction box on the plan sheet should be "NEMA 4X, C.I. or S.S.". This will result in a more economical installation. Our current standard detail show the Junction Box in the lower part of the traffic barrier where the box must be curved at the surface to match the barrier. The junction box should be moved up in the barrier. This attached detail includes the proposed revisions.

2.  Use of Richmond Rocket Inserts for Anchoring Luminares to Traffic Barriers

The Richmond Rocket Inserts are supplied with bolts that are inadequate length to properly anchor the luminare. The region recommends an embedded plate with attached nuts and the bolt/length specified. See Ray Shaefer for details.

3.  Location of a Junction Box in a Traffic Barrier with a Thrie Beam Attachment

The NW Region recommends that we do not locate any junction boxes in the end traffic barrier sections. Apparently this has been detailed in the past and resulted in conflict between the junction box and the thrie beam connection at the face of the barrier.

Please implement these revisions on any projects you are currently working on (being detailed) and future projects as well.



cc w/attach: Joe Fahoum, 7340