OVERHEAD SIGN/VMS STRUCTURE
PART 1 GENERAL
1.1SECTION INCLUDES
A.Fabrication and installation of overhead sign structure
B.Fabrication and installation of overhead VMS structure and catwalk
C.Fabrication and installation of appurtenances
1.2RELATED SECTIONS
A.Section 05120: Structural Steel
B.Section 09972: Painting for Structural Steel
1.3REFERENCES
A.AASHTO M 111: Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel
Products
B.ASTM A 36: Carbon Structural Steel
C.ASTM A 53: Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and
Seamless
D.ASTM A 194: Carbon Steel, Alloy Steel, and Stainless Steel Nuts for
Bolts for High Pressure or High Temperature Service, or Both
E.ASTM A 307: Carbon Steel Bolts, Studs, and Threaded Rod 60,000 PSI
Tensile Strength
F.ASTM A 500: Cold-Formed Welded and Seamless Carbon Steel
Structural Tubing in Rounds and Shapes
G.ASTM A 563: Carbon and Alloy Steel Nuts
H.ASTM A 595: Steel Tubes, Low-Carbon or High-Strength Low-Alloy,
Tapered for Structural Use
Overhead Sign/VMS Structure
I.ASTM A 709: Structural Steel for Bridges
J.ASTM A 1085: Cold-Formed Welded Carbon Steel Hollow Structural
Sections (HSS)
K.ASTM C 1107: Packaged Dry, Hydraulic-Cement Grout (Nonshrink)
L.ASTM D 4066: Classification System for Nylon Injection and Extrusion
Materials (PA)
M.ASTM F 436: Hardened Steel Washers Inch and Metric Dimensions
N.ASTM F 594: Stainless Steel Nuts
O.ASTM F 844: Washers, Steel, Plain (Flat), Unhardened for General Use
P.ASTM F 959: Compressible-Washer-Type Direct Tension Indicators for
Use with Structural Fasteners
Q.ASTM F 1554: Anchor Bolts, Steel, 36, 55, and 105-ksi Yield Strength
R.American Institute of Steel Construction (AISC)
S.American Petroleum Institute (API)
T.AWS D1.1 Structural Welding Code – Steel
U.RCSC Specification for Structural Joints Using High-Strength Bolts 2020
(Research Council on Structural Connections)
V.UDOT Structural Steel Construction Manual
1.4DEFINITIONS
A.Snug Tight – The tightness that is attained with a few impacts of an impact
wrench or the full effort of an ironworker using an ordinary spud wrench to bring the plies into firm contact.
B.Levelling Nut – Nut below base plate in anchor bolt assembly used to
support base plate to control the final elevation and angle of the attached overhead sign or VMS structure post.
C.Refusal of feeler gauge (bolt tension verification) – The condition where
the gaps between the Direct Tension Indicator (DTI) and unturned element or washer, are too tight to permit the insertion of a 0.005 inch feeler gauge from the edge of the washer to the shank of the bolt. Overhead Sign/VMS Structure
D.Open gap (bolt tension verification) – A gap between the DTI and
unturned element or washer that does not refuse a feeler gauge, indicating that the gap is at least 0.005 inch.
1.5SUBMITTALS
A.Shop drawings of all fabricated materials for review. Include at least the
following:
1.Exact locations of all handholes, threaded inserts, longitudinal
seam welds, and shop splices
2.Sign frame, VMS panel, catwalk, ETC gantry and other
appurtenances
B.Material submittals for information.
1.Manufacturer’s certificate of compliance for bolts, nuts, and
washers
a.Refer to Section 05120.
2.Certified mill test reports (MTR) for all fabricated structure
materials, seven calendar days before fabrication, including material manufactured outside of the United States
a.Clearly indicate country of origin on MTR.
3.Charpy V-notch test results
4.Chemical composition with regard to silicon content for structural
pipe
5.Dimensional measurements for A 36 structural pipe meeting
tolerances specified in ASTM A 53.
C.Bolting Procedures for review
1.Bolting procedure for high strength and anchor bolts that meets the
RCSC Specifications for Structural Joints Using High-Strength Bolts including at least the following:
a.Handling, storage and identification of fasteners
b.Preparation of bolted parts
c.Pre-installation verification procedure. Refer to Section
05120 for requirements. 1) Not applicable to anchor bolts
d.Installation
1) Diagram and label the components of the bolt assembly. 2) Show the location and orientation of the components. 3) State whether the bolt head or the nut will be turned. 4) Include procedures for both snug tight and slip critical installations. 5) Include specific diagrams and procedures for order that bolt assemblies are to be tightened. Overhead Sign/VMS Structure
e.Procedures for drawing connecting elements into full contact
with each other.
f.Inspection
1) Provide tasks the installer is to perform prior to and during bolting installation in order to ensure bolts assembly was properly tightened. 2) Provide tasks for both snug tight and slip critical installations.
g.Personnel responsible for each activity.
D.Welding submittals for information
1.Weld Procedure Specifications and Procedure Qualification
Records according to AWS D1.1.
2.Welder Qualification Record for each operator, process, and
position as required by AWS D1.1.
a.Include a letter from the Fabricator that states the certified
welders have been using the process without an interruption of more than six months since being certified.
E.Documentation of fabricator’s AISC certification for information.
F.Non-Shrink Grout for information
1.Manufacturer product data sheet, installation and curing
recommendations.
G.Construction documentation for information
1.Pre-installation verification test results
2.Bolt Certification Forms for information
a.Submit Bolted Field Splice Certification, Anchor Bolts
Certification, and Bolted Sign Frame Connection Certification.
3.Forms can be found at the UDOT website. Refer to:
http://www.udot.utah.gov/go/standardsreferences.
PART 2 PRODUCTS
2.1MATERIALS
A.Structural Steel
1.Structural pipe
a.Use low carbon steel according to ASTM A 53 Grade B,
ASTM A 500 Grade B, ASTM A 1085, ASTM A 36, or API-5L Grade B or higher. 1) A 36 pipe must meet dimensional tolerances according to ASTM A 53. Overhead Sign/VMS Structure
b.Meet chemical composition requirement of silicon either 0.00
to 0.04 percent or 0.15 to 0.25 percent.
2.Hollow Structural Section (HSS)
a.Refer to ASTM A 500 Grade B, or ASTM A 1085.
3.Other structural steel
a.Refer to ASTM A 36.
B.Fasteners
1.Anchor bolts, nuts, and washers
a.Refer to ASTM F 1554 Grade 55 for bolts.
b.Refer to ASTM A 194 Grade 1, or A 563 Grade A for nuts.
1) Use heavy hex nuts. 2) Use Grade specified or better. 3) Proof test nuts to Grade 1 or A requirements as applicable.
c.Refer to ASTM F 436 for washers.
d.Galvanize bolt assembly.
2.High strength bolts, nuts, and washers
a.Refer to Section 05120.
b.Use direct-tension indicators (DTI).
c.Galvanize bolt assembly.
3.Steel rod
a.Refer to ASTM A 36 for threaded round bar.
b.Refer to ASTM A 563 Grade DH or ASTM A 194 Grade 2H
for nuts. 1) Use hex nuts.
c.Refer to ASTM F 436 Type 1 for washers.
d.Galvanize rod assembly.
4.Stainless steel machine screws, nuts, and washers
a.Provide 18-8 stainless steel machine screws with round
heads.
b.Refer to ASTM D 4066 for Nylon flat washers.
1) White or clear in color
c.Provide grade 304 or grade 316 stainless steel washers.
d.Refer to ASTM F 594 for stainless steel nylon lock nuts
5.Galvanized coatings for bolt and rod assemblies
a.Refer to the specified fastener ASTM for permitted
galvanized coating standards.
b.Provide compatible coatings for components in the bolt
assembly.
Overhead Sign/VMS Structure
2.2PAINT
A.Three-part coating system
1.Refer to Section 09972.
a.Galvanization can be substituted for zinc primer if compatible
with coating system.
b.Use color as shown
B.Zinc-rich touch up paint (paint containing zinc dust) for repair of minor
damage to galvanizing
1.Use inorganic paint with 65 to 69 percent metallic zinc by weight, or
greater than 92 percent metallic zinc by weight in the dried film.
2.3NON-SHRINK GROUT
A.Refer to ASTM C 1107.
2.4SHOP INSPECTION
A.Notify Engineer immediately upon placing fabrication order to allow time to
schedule shop inspection.
1.In-state work requires 7 days advance notice; out-of-state work
requires 30 days advance notice.
2.Schedule shop inspection before beginning fabrication.
3.Facilitate inspection procedures on site.
4.Supply adequate personnel to perform quality control.
2.5FABRICATION
A.Fabricate according to UDOT Structural Steel Construction Manual and
AWS D1.1.
B.Fabricator must be AISC certified as a Highway Component Manufacturer
(CPT).
C.Position longitudinal seam welds in post and mast arm sections in areas of
lower stress as follows:
1.For full span type structures locate the seam weld for the mast arm
in the upper quadrant of the mast arm (compression side under dead load).
2.For cantilever type structures locate the seam weld for the mast
arm in the lower quadrant of the mast arm (compression side under dead load).
3.Locate the seam weld for the posts on the span side (compression
side under dead load). Overhead Sign/VMS Structure
D.Perform Charpy V-Notch tests according to ASTM A 709 for temperature
Zone 2, on tension members with a ½ inch steel thickness or greater and as shown.
E.Drill or punch bolt holes and slots to finished size.
1.Thermally cut slotted holes by plasma, laser, or oxygen-acetylene
methods.
a.Do not use flame cutting on bolt holes.
2.Grind hardened thermally cut edge to a maximum surface
roughness of 1,000 micro-inch and the conical taper of the hole must be maintained within tolerance.
F.Weld 1½ inch diameter inserts in holes at the bottom of the mast arm as
shown.
1.Thread inserts before galvanizing.
2.Provide galvanized or brass plugs.
G.Use ultrasonic testing on the post to base plate welds, shop splice welds,
and field splice welds in post and mast arm.
1.Acceptance criteria according to AWS D1.1 Table 6.3 (connections
in tension).
2.One-time repair by welding of deficient weld is allowed without
written authorization from the Engineer
H.Verify fit up of the structure by assembling the structure in the shop.
I.Galvanize all steel elements according to AASHTO M 111.
J.Paint base plates, posts, mast arms, splice plates, appurtenances and
associated hardware when shown.
1.Apply intermediate and top coats of paint over galvanization.
a.Follow paint manufacturer’s recommendations for surface
preparation of galvanization when applicable.
b.Apply only primer coat to splice plates and base plates
before installation.
K.Attach the sign to the frame using stainless steel machine screws, nuts
and washers.
1.Tighten nuts to achieve contact between sign panels and frame.
a.Do not damage the reflective sheeting by over-tightening.
Overhead Sign/VMS Structure
PART 3 EXECUTION
3.1PREPARATION
A.Verify the roadway cross-section information, sign dimensions, foundation
location, and clearances shown before fabrication.
B.Field verify the post height and length of mast arm after concrete forms,
reinforcing steel and anchor bolts are placed and before concrete placement.
C.Perform Pre-Installation Verification according to the authorized bolting
procedures.
D.Provide the Engineer with access to the sign panels before installation so
the sign frames can be inspected and any corrective actions taken before installation on the structural pipe.
1.Inspect the sign sheeting to ensure that no damage occurred when
bolts between frame and aluminum sheeting were tightened.
2.Verify that all bolts are installed and none were loosened or lost
during transportation.
3.2ERECTION
A.Do not weld, cut or drill steel elements in the field.
B.Meet vertical clearance requirements as shown, during all conditions.
C.Tension Anchor Bolts
1.Clean and lubricate exposed threads of anchor bolts and nuts
immediately before installing nuts.
2.Create a snug tight condition by tightening top anchor bolt nuts
against the base plate until full contact is made at final position.
3.Tighten top nuts one-third turn past snug tight.
4.Fill out Anchor Bolt Certification form in the presence of the
Engineer during bolt installation.
D.Install high strength bolts according to Section 05120 and the authorized
bolting procedures.
1.Install to snug tight when shown.
2.Use direct tension indicator washers at field splice locations and as
shown.
3.Installed bolts must meet the minimum installation refusals
requirement in Section 05120, and must maintain at least one open gap (feeler gauge not refused). Overhead Sign/VMS Structure
4.Fill out Bolted Field Splice Certification and Bolted Sign Frame
Connection Certification in the presence of the Engineer while the bolts are being placed.
a.Provide necessary equipment and access to allow inspector
access to the connection.
E.Install sign panel frames, VMS panel, and ETC gantry onto mast arm as
shown.
1.Fit bracket plate tight against the structural pipe and seat the
keeper bar in the bracket plate as shown.
F.Fill the void between the base plate and top of foundation with non-shrink
grout after completing the sign erection.
1.Cover and protect the grout according to manufacturer
requirements and suggestions.
G.Cover signs that require temporary covering with an opaque non-paper
material.
1.Secure cover at the rear of the sign so that the sign is not damaged
and the covering remains secure during inclement weather.
2.Maintain covering until removed.
H.Touch up minor damage to galvanization that occurs during transportation
and erection of galvanized members.
1.Clean the repair area to remove any water, oil, grease, preexisting
paint, debris, corrosion, and loose galvanization next to the damaged area.
a.Use a wire brush or other hand tool.
b.Provide smooth transitions from area of bare metal to areas
of galvanizing to remain.
2.Apply two coats of zinc-rich touch up paint to the repair area
allowing the paint to dry between each coat.
3.3PAINTING
A.Paint splice plates and base plates after installation of bolt and anchor
assemblies.
1.Apply intermediate and top coats of paint over galvanization
according to Section 09972.
B.Repair damage or defective coating according to Section 09972.
Overhead Sign/VMS Structure
3.4LIMITATIONS
A.Do not open traffic under the overhead sign structure if any of the
following conditions are true:
1.Information contained on a removed sign is not being provided by a
new or temporary sign.
2.Information on the new sign conflicts with an existing sign.
3.New sign conflicts with the current striping.
4.New sign obstructs an old sign that contains required information.
5.The minimum vertical clearance as shown is not met.
6.There is a missing bolt assembly, missing components of a bolt
assembly, or correctly installed bolt assemblies in field splice or the base plate connections.
7.Sign panel or VMS assemblies are not seated and bolted as
shown.
8.Engineer is concerned that a component of the structure or
attachment to the structure is not securely attached as shown.
B.Perform work only at times when winds are expected to be less than 15
mph and there are no other adverse weather conditions.
END OF SECTION
Overhead Sign/VMS Structure
Utah revises spec sections through supplementals and new editions. We check this one every week and email you the day it changes. Free, no account.
Source: Utah Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 815–824 of 1,331.
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