Review the LRFD Specification for
Structural Supports for Signs,
Luminaires, and Traffic Signals
NORMAN MCDONALD, PE
AASHTO SCOBS
Technical Committee T-12
Saratoga Springs, New York
APRIL 20, 2015
AASHTO SCOBS- Columbus 2014
• June 26, Ballot Item 31 voted 43-yes, 2-no, and 3-abstain
• Yellow pages (Revision 1) of 24 pages
• 3.8 wind load
• 3.9.3 design loads for vertical supports
• 5.6.6 holes and cutouts
• 6.13 welded members (missing article)
Revision 1 continued
• Wind speed for Alaska and Hawaii
• New bolt circle figure with commentary
• Corrections for Section 11 Tables
• 14.3.4 longitudinal seam weld note, MT note
• 15.8 deleted FRP commentary
Review Timeline
• January 23 document ready for review
• Finish review by end of February
• 100 e-mails and 2 months later
Sections and Queries
• Section 1: Introduction………………….…..….5 queries
• Section 2: General Features of Design…...3 queries
• Section 3: Loads…………………………….…….10 queries
• Section 4: Analysis and Design….…..……….3 queries
• Section 5: Steel Design………………….……..29 queries
• Section 6: Aluminum Design………..………45 queries
Sections and Queries
• Section 7: Prestressed Concrete Design.…7 queries
• Section 8: Fiber-Reinforced Composites…12 queries
• Section 9: Wood Design………………………..11 queries
• Section 10:Serviceability…………….…….….…2 queries
• Section 11: Fatigue Design………….…………17 queries
• Section 12: Breakaway Supports……………..2 queries
Sections and Queries
• Section 13: Foundation Design………………5 queries
• Section 14: Fabrication, Mtls, Detailing...32 queries
• Section 15: Construction………………..…….21 queries
• Section 16: Inspection and Reporting…...4 queries
• Section 17: Asset Management…….……….3 queries
Appendices and Queries
• Appendix A: Span Wire……...4 queries
• Appendix B: Design Aids….…7 queries
• Appendix C: Alternate Methods for Fatigue Design…………….………………….8 queries
• Appendix D: Detailed Element Descriptions………….…………...3 queries
Definitions
1.2 Definitions Q: “High-Mast High-Level Tower (HMLT)” has the same acronym as “High-Mast Luminaire
Tower (HMLT)” and appears to be different wording for the same thing. Should these entries be:
1. Combined into a single entry “High-Mast Luminaire Lighting Tower or High-Mast
High-Level Tower (HMLT) …”
2. Kept as separate entries with this revised entry for the second one “High-Mast High-
Level Tower —see High-Mast Luminaire Tower.”
3. Left the way they are but with a different acronym “High-Mast High-Level Tower
(HMHLT)”?
A: Use option 1 as revised above
1.2 Definitions Q: Abbreviation for Standard Specifications for Structural Supports for Highway Signs,
Luminaires, and Traffic Signals?
A: LRFD SLTS-1
References- Wording
C2.4.1 Q: Need a reference for A Study of Roadway Lighting.
A: We will ask Jay for the reference- see the note sent with this attachment.
2.5 Q: Should the text “travel lanes” be “traveled way”?
A: “traveled way”
2.6.1 Q: Please check the sense of the sentence: “In these cases, the minimum vertical clearance
requirements for overhead signs do not apply but the minimal vertical clearance to not post the
bridge should be maintained.” Should “not post the” be removed?
A: change the sentence to “Although the minimum vertical clearance requirements for overhead
signs do not apply in these cases, a minimal vertical clearance to avoid posting the bridge
should be maintained.”
Section 3
• Permissions for ASCE Basic Wind Speed Maps
• New high-resolution images for three figures showing loads on structural supports
• Figure 3.9-1, 3.9-2 and 3.9-3
High-resolution images
Consistent Units
5.3 Q: Is “kip in.” the same as “kip-in.”? As “kip/in.”?
A: Please consistently use the notation “kip-in.” The notation “kip-in.” means “1000 pounds
multiplied by 1 inch”. Do not use “kip in.” in place of “kip-in.” or “kip/in.”.
C5.5.3.1 Q: Please provide a complete citation for “NCHRP 10-80” to add to References.
Puckett, J. A., M. G. Garlich, A. Nowak, and M. Barker. 2014. Development and Calibration of
AASHTO LRFD Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic
Signals, NCHRP Report 796. Transportation Research Board, National Research Council,
Washington, DC.
[NCHRP Report 796 is the final report for NCHRP Project 10-80. Please note that this reference is
already included in the reference list of Article 5.17, but the current version lists different authors.
I have used the author list that is included in the actual NCHRP Report 796.]
Section 5
• Article 5.6.2—Minimum number of sides
• 5D or 8, whichever is larger
• C5.6.2 last paragraph about fluted cross sections is missing
• 5.6.3 Transverse Plate Thickness for Fatigue Design
ASTM References- Section 5
5-38 References Q: Added references to ASTM:
A706/A706M-14
A572/A572M-13a (we created this reference based on the current standard)
A595/A595M-14
A615/A615M-14
A706/A706M-09b
A1011/A1011M-14 (we created this reference based on the current standard)
based on citations in text. Please confirm these are the correct standards.
A: These appear to be the correct standards.
Section/ Articles
6-22 Table 6.5.1-10 Q: Should Eq. 6.5.1-40 be referenced in Section Article 6.9.1.2?
A: Please create new Article 6.9.1.3 for “Rivet in Round Hole”:
6.9.1.1—Bolt in Round Hole
6.9.1.2—Bolt in Slotted Hole
6.9.1.3—Rivet in Round Hole
For a rivet in a round hole, the bearing design stress shall be determined using Eq.
6.5.1-40.
6.9.1.34—Pin in Round Hole
6.9.1.45—Screw in Round Hole
Please also revise/renumber the Article numbers in Table 6.5.1-10 for “Rivet in a round
hole”, “Pin in a round hole”, and “Screw in a round hole”.
Section 6 Flowcharts
Numbered steps and format
10-5 Q: Numbered the steps in the outlined process for clarity. Please check that they are numbered
correctly.
A: The steps are numbered correctly, but the text is still difficult to read. There are numerous
inconsistencies with regards to use of italics, indentation of text, and blank lines between the text
associated with each procedural step. I suggest showing the procedure using the same formatting
style as is used in AASHTO LTS-6 (2013) Article C5.17.5.2 (i.e., Do not use italic text except for
variables and formulas. Instead, use indents to help with readability.). See below for suggested
revisions.
No change needed
11-1 11.2 Q: Should “galloping” be defined? If so, please provide.
A: No, I think it is well defined in C11.7.1.1 where it first appears.
Scope, Definitions, Notation
15.1 Article 15.1 should be “Scope.” I took the first paragraph from the existing “General” article and
used it for a new Scope section since it matches the scope text in the other sections. Please confirm
that this is correct.
A: OK
15.2 and 15.3 Added Definitions and Notation articles (15.2 and 15.3, repectively). Definitions were drawn from
article C15.3.3 on pg. 15-4 and 15-5, and article 15.11.1 on pg. 15-11. Notations were drawn from
article C15.3.3 on page 15-5. Please confirm that this was done correctly and that there should be
no additions or deletions.
A: OK
Appendices
• Appendix A: hanging box figure needs to be redrawn
• Appendix B: need permission to use formulas for maximum stresses Table B.2-1
• Appendix B: need permission to use maximum deflection and slope Table B.4-1
