SECTION 754
HIGHWAY SIGNS
754.01 DESCRIPTION
This work item consists of furnishing, fabricating, and installing highway signs, delineators,
and supporting structures.
754.02 EQUIPMENT
Reserved
754.03 MATERIALS
Item
Section
Reinforcing Steel
612
Concrete, Class AE
802
Highway Signs and Posts
894
Fabricate the sign faces according to the detail drawings and the alphabets shown in the
contract, MUTCD, the Standard Highway Signs published by FHWA, and the Standard
Highway Signs Supplemental Manual published by the NDDOT. The last number in the
sign numbers shown is the width of the sign required.
Use screening inks that are compatible with the reflective sheeting backgrounds.
Use the Department generated tabulated message computations for variable length
signs when laying out the sign faces at the fabricator’s shop. The Department will furnish
the tabulated sheets upon request after contract execution.
754.04 CONSTRUCTION REQUIREMENTS.
A. Locating and Positioning Signs and Sign Structures.
Erect signs and delineators located less than 30 feet from the pavement edge with the
sign face truly vertical and turned 93 degrees away from the center and direction of
travel of the lane which the facility serves. Erect signs located 30 feet or more from the
edge of the pavement edge with the sign face truly vertical and aligned 90 degrees from
the center and direction of travel of the lane which the offset sign serves. Position signs
and delineators located at the point where lanes divide or on curves to minimize
specular reflection directed toward traffic.
B. Sign Fabrication.
1. General.
Use directly applied reflective sheeting, cut to the specified shapes for the
messages, symbols, and borders on variable message signs. Apply the message,
symbols and border as specified by the reflective sheeting manufacturer.
2. Fabrication of Sign Backing.
Cut sign backing to size and shape and fabricate to be free of defects. Fabricate
sign backings that are larger than manufacturer’s material in sections with vertical
butt joints. Use a minimum of 24 inch wide sections. If more than two sections of
backing are required, place the wide sections on the outside positions and the
narrower one between. Use the widest manufacturer’s sections of sheeting before
narrower sections are used. The surface of all signs shall be plane surfaces.
Complete all cutting, shearing, and drilling or punching of holes (except mounting
holes for demountable letters, numerals, symbols, and borders) before degreasing
metal and applying reflective sheeting.
3. Fabrication of Flat Sheet Signs.
Apply reflective sheeting to the background of flat sheet signs according to the
reflective sheeting manufacturer’s recommendations.
Apply messages, symbols, and borders by directly applying reflective sheeting or by
screening. Apply directly applied reflective sheeting according to the manufacturer’s
recommendations.
If the reflective sheeting is larger than the sign backing, place the reflective sheeting
on each section with no splices on the individual panels. Use sheeting from the same
manufacturer’s lot on each individual sign.
Process and finish the sign face with material according to the reflective sheeting
manufacturer’s recommendations.
Finish the signs to have a smooth, uniform surface with clear cut and sharp
messages, symbols, and borders.
4. Fabrication of Panel Signs.
Apply reflective sheeting to the background of panels according to the reflective
sheeting manufacturer’s recommendations.
If splicing the reflective sheeting, overlap the splice a minimum of 3/16 inch. Splice at
a 90 degree angle to the length of the panel. Make the splices uniform and neat
throughout the entire length. Do not splice any individual panel more than 2 times,
and leave at least 8 feet between adjacent splices.
Extend the reflective sheeting over the edges and down the side legs a minimum of
1/16 inch.
If guide sign symbols are required on larger guide signs, rivet the symbols to the
larger guide sign.
5. Date of Fabrication.
Date all signs receiving new sign facings with the month and year fabricated. Place
the date on the back of the metal backing on the lower corner of sign near the edge
closest to traffic so that is legible from the ground. Use 1/4 inch high numbers on a 21/4 inch long by 1-3/4 inch pressure sensitive label. Imprint the numbers 1 through
12 on the upper part of the label, with the last two digits of four consecutive years
printed across the bottom. Punch out the number of the month and the year of
fabrication.
C. Shipping and Storage.
Before shipping or storage, ensure that all signs are free of moisture and that all inks are
thoroughly dry. Keep all packaged signs dry. Store and ship signs off the ground in an
upright position.
D. Erection of Sign Supports and Delineators.
1. General.
Confirm the support lengths with the Engineer before ordering sign support posts.
Use a driving cap when driving a sign support.
Firmly set all sign supports and plumb after erection.
Construct all concrete foundations with the top sloped enough to drain away from the
sign support. Give all exposed concrete above ground surface a rubbed finish.
2. Anchor for Telescoping Perforated Tubes Supports.
Drive anchors for telescoping perforated tubes supports a maximum of 4 inches
above the ground or surfacing.
Install the specified length of anchor unless the Engineer determines a shorter length
is sufficient due to good soil bearing developed when driving the anchor. The
Engineer may reduce anchor lengths to a minimum of 3 feet. If set in concrete or
bituminous, omit the anchor plate.
Core the surfacing before installing the anchor unit and fill the cored area with like
material that matches the surrounding surfacing.
3. Single Tubular Sign Supports.
Set tubular sign supports in a concrete foundation. Place plates so the tapered bolt
slot tapers toward approaching traffic.
4. Overhead Sign Structures.
a. General.
Fabricate all overhead sign structures so that only bolted assembly is required in
the field. The Engineer will allow drilling to fasten an overhead sign to a bridge.
Do not field weld.
b. Anchor Bolt Installation.
Use a steel template to accurately locate and hold the anchor bolts plumb and in
proper alignment. Put this template in place during placement of the concrete
base and leave it in place a minimum of 24 hours after the concrete placement is
complete. Leave the support cage used to position the anchor bolts in the
concrete foundation. The Engineer will reject the base if anchor bolts are out of
position or if the anchor bolts are greater than 1:20 out of plumb. Do not alter the
base or bend the anchor bolts to straighten them or move them into position.
c. Anchor Bolt Tightening.
Tighten top and leveling nuts of the anchor bolts according to the following
sequence:
(1) Bring all leveling nuts to full bearing on the bottom of the base plate. Keep
the bottom of the leveling nut as close to the concrete base as practicable,
and not more than one inch above the top of the concrete base. Thread
leveling nuts onto the anchor bolt to provide at least a 1/4 inch projection of
the bolt above the top nut when in its tightened position.
(2) Generously add beeswax or equivalent to the top nut bearing face and top
nut internal threads prior to placement on the anchor bolt. Tighten all nuts
to a “snug” condition. The Department defines "snug" as the tightness
attained by the full effort of a person using a wrench with a length equal to
14 times the diameter of the anchor bolt (minimum wrench length shall be
18 inches). Apply the full effort required to achieve a “snug” tight condition
as close to the end of the wrench as possible, and continue until the nut
stops rotating. Tighten by leaning back, pulling firmly, and using one’s
entire body weight on the end of the wrench (with feet braced to prevent
slipping). Accomplish snug tightening in a minimum of two separate passes
of tightening. Sequence tightening by tightening in each pass the opposite
side nut, to the extent possible, until all the nuts in that pass have been
snugged.
(3) Check the “snug” tightness of the nut in the presence of the Engineer after
completing nut snugging as described above but prior to commencing step
(4) below. Check the “snug” tightness of the nuts (top and leveling) by
applying a torque to the nut according Table 754-01.
Table 754-01
Bolt Diameter
Torque
(inches)
(foot-pounds)
1
100
1-1/4
200
1-1/2
300
1-3/4
400
2
500
2-1/4
700
2-1/2
800
(4) After step (2), ensure that the top nut and leveling nuts are in full bearing on
the base plate. If any gap exists between either nut and the base plate,
insert a beveled washer between the nut washer and the base plate to
eliminate the gap. Use a stainless steel Type 304 washer of the same
diameter as the hardened washer, which is beveled so that the gap
between the nut and the base plate is eliminated. Retighten all nuts
according to step (1) and (2) above if beveled washers are added.
(5) Tighten all top nuts an additional 1/3 turn using a hydraulic wrench. Tighten
all of the nuts in two separate passes of equal increment turns. Use a
sequence of tightening in each pass so that the opposite side nut, if
possible, shall subsequently tightened until all the nuts in that pass have
been turned. Do not allow the leveling nut to rotate during top nut
tightening.
(6) Check the tightness of the nuts in the presence the Engineer a minimum of
48 hours after completing step (4). Apply torque to the nut in accordance
with Table 754-02.
Table 754-02
Bolt Diameter
Torque
(inches)
(foot-pounds)
1
300
1-1/4
630
1-1/2
1,120
1-3/4
1,820
2
2,770
2-1/4
4,010
2-1/2
5,550
After the anchor bolt nuts have been checked for tightness, the Engineer will
perform ultrasonic testing and calibration procedures for final acceptance. The
Engineer will perform these tests to ensure that no flaws in the bolts have been
introduced during the construction process and no loose nuts or washers exist.
The Engineer will tap each nut (top and leveling) with a 24 ounce ball peen
hammer to check for looseness. A tight nut produces a sharp ringing sound, and
a loose nut produces a dull sound. The Engineer will tap each washer on one
side while placing one hand on the other side of the washer. If the washer
moves, the nut is not properly tightened. The Engineer will use a wrench with a
length equal to 14 times the diameter of the anchor bolt (minimum 18 inches)to
check the tightness of each nut. If the Engineer is able to rotate a nut as a result
of the application of a person’s full effort on the end of the wrench, the nut is not
properly tightened. If the Engineer finds any nut or washer to be loose as a result
of the above acceptance procedure, tighten such loose nuts according to Steps
(1) through (5) above. If any nuts require tightening after the initial installation,
remove and reinstall nuts and washers and, if necessary, remove and re-erect
the entire structure at no cost to the Department.
Test to verify the absence of flaws prior to the erection stage. The Engineer will
reject the entire base installation because of reflectors found with an indication
rating less than 15 decibels.
d. Erection Procedures.
Erect the overhead sign supports according to the following sequence:
(1) Place leveling nuts and washers on all the anchor bolts. Initially place
leveling nuts 1/4 inch above the concrete foundation. Bring the nuts into
level with the highest nut above the foundation. Do not allow the clearance
between the concrete foundation and the bottom leveling nuts to exceed 1
inch maximum.
(2) Place the column, without the truss or arm brackets attached, on the leveled
bottom nuts and washers.
(3) Apply beeswax or the equivalent to all top nut bearing faces and the top nut
internal threads prior to placement on the anchor bolt. Place the two
perpendicular top nuts and the two parallel top nuts to the sign face (in its
final position) on the anchor bolts, along with their corresponding washers,
and snug tighten them.
(4) Level the column base plate by adjusting only the nuts perpendicular and
parallel to the sign face in its final position.
(5) Place the remaining top nuts and washers on the anchor bolts and loosely
snug tighten them.
(6) Tighten all bottom and top nuts as specified in Sections 754.04 D.4.c.(1)
through 754.04 D.5.c.(4).
(7) Place the assembled arm bracket or truss, without the sign, on the erected
column. Tighten all bolts by the turn-of-nut method specified in Section
616.03 C.3.c.(1) Table 2. Do not reuse any nuts and bolts loosened or
removed after being fully tightened. The Engineer will not consider
previously tightened bolts that have been loosened by the tightening of
adjacent bolts as reused and they may be retightened.
(8) Place the sign panel on the erected arm bracket or truss.
(9) Check the anchor bolt nuts connecting the column base to the concrete
foundation for tightness according to Section 754.04 D.5.c.(5).
5. W-Shaped Sign Supports.
a. Breakaway Base Plates
Assemble breakaway base plates with the bolt torqued to plan requirements.
Place the plates so the tapered bolt slot tapers toward approaching traffic.
b. Flame Cutting of W-Shape Posts.
The Engineer will allow the use of a gas cutting torch for cutting metals or
preparing joints. Do not flame cut carbon steel above 0.30 percent carbon, high
alloy steels, heat treated steel, and plated metals unless subsequent corrective
treatment is provided as approved by the Engineer.
Perform flame cutting using the oxyacetylene gas method. Do not deviate from
true lines more than 1/16 inch. Repair edge defects according to Section 3.2 of
AWS Structural Welding Code, as amended by AASHTO Specifications for
Welding of Structural Steel Highway Bridges. The roughness of flame cut
surfaces shall be less than an ANSI roughness value of 1,000 microinches.
Completely remove slag produced during flame cutting.
If flange plates or other members are cut to a curve, make cuts uniform to the
required radius. Do not make a series of straight cuts tangent to the curve.
If cutting the ends of members that are to take bearing with a torch, make a
suitable allowance in their length to permit proper milling or planing.
Prepare joints for welding using flame cutting or flame gouging methods.
Remove slag and oxidized metals.
c. Edge Finishing.
If using the shearing method to form field splice plates and stiffeners that have a
thickness less than 1/2 inch, leave a minimum of 1/8 inch of extra material
beyond the specified dimensions. Remove the extra material by machining or
planing.
If using the shearing method to form structural steel plates that have a thickness
of 1/2 inch or greater, leave a minimum of 1/4 inch of extra material beyond the
specified dimensions. Remove the extra material by machining or planing.
F. Mounting Flat Sheet Signs.
If washing signs is necessary, use water and a soft bristle brush or a sponge.
Bolt flat sheet signs to the supports and place a nylon washer between the flat washer
and the sign face.
G. Removing and Resetting Signs and Supports.
Remove and reset existing signs and supports as specified. Stockpile all signs and
supports not to be reset at designated locations within the project limits. The Engineer
will arrange to have stockpiled signs removed from the project limits and delivered to the
Department’s facility.
Replace removed or reset signs and supports that are damaged during removing,
resetting, or stockpiling at no additional cost to the Department.
Remove existing signs and supports as construction progresses, and immediately reset
or install. Place all signs and supports on the project site at the time construction
begins. The Engineer will allow the temporary reset of existing signs, or the temporary
installation of new signs. Include the cost of installing and resetting signs temporarily in
the price bid for other items.
H. Remove Sign Foundations.
Remove steel supports, foundations, and H-pile footings and restore the surface to
match the surrounding area. Remove foundations and H-pile footings to a depth of 2 feet
below the ground line.
J. Overlay Panel Sign Refacing.
Provide overlay panels from 0.063 inch aluminum as specified in Section 894.01 A.1
“Flat Sheet Aluminum”.
Remove the legend, border, and symbol on those signs that have demountable copy
and place overlay panels on the signs. Do not remove direct applied reflective sheeting
legends, borders, and symbols. Direct apply the new legends, borders, and symbols to
the overlay panels and install on the existing signs.
Install overlay panels on the existing signs with aluminum blind fasteners 5/32 inch
diameter with 1/8 inch out the back of the existing sign backing. Abut the panels
together. Cut the legends, numerals, symbols, and borders where they cross joints.
Fabricate overlays on signs that are larger than manufactured overlay panels as follows:
Use overlay panels between 1.5 and 4 feet wide.
Use panels with a minimum length of 8 feet.
If the overlay panels do not cover the full height of the sign, place the overlay panels on
the lower portion of the sign first so the longer side of the panel is vertical. Place the
remaining panels above these panels with their long side placed horizontally.
Place rivets at 12 inch intervals around the outer edge of the overlay panel and spaced 1
inch from the outer edges. For overlay panels greater than 24 inches wide, place rivets
down the center of the overlay panel at 12 inch intervals.
K. Auxiliary Signs.
Make the auxiliary signs used with route markers the same background color as the
route markers:
 Interstate, Blue;
 Interstate Business Loop, Green;
 State, White; and
 County, Blue.
754.05 METHOD OF MEASUREMENT.
The Engineer will measure as specified in Section 109.01, “Measurement of Quantities” and
as follows:
A. Flat Sheets, Panels, and Extruded Aluminum Panels.
The Engineer will measure flat sheets, panels, and extruded aluminum panels for signs
to the closest 1/10 square foot.
B. Galvanized Steel Posts - W-shaped Posts.
The Engineer will measure the post length and the pile length when determining the
length of W-shaped posts.
754.05 BASIS OF PAYMENT.
Pay Item
Flat Sheet for signs – Type __Reflective Sheeting
Delineators – Type __
Remove and Reset Delineators
Diamond Grade Delineators – Type __
Steel Galvanized Posts – Telescoping Perforated Tube
Galvanized Steel Post – Standard Pipe
Galvanized Steel Post – W-Shape Posts (Two or More)
Stub Post __IN
Panel for Signs – Type __ Reflective Sheeting
Overlay Panel – Type __ Reflective Sheeting
Extruded Aluminum Sign Panel – Type __ Reflective Sheeting
Interstate Mile Post – Type __
Reference Marker – Type __
Pay Unit
Square Foot
Each
Each
Each
Linear Foot
Linear Foot
Linear Foot
Each
Square Foot
Square Foot
Square Foot
Each
Each
Reset Sign Panel
Reset Sign Support
Reset Mile Post
Object Markers – Type __
Object Markers – Culverts
Class AE Concrete – Sign Foundations
Remove Sign Foundation
Overhead Sign Structure Bridge Mounted
Overhead Sign Structure __FT Cantilever
Overhead Sign Structure __FT Truss
Each
Each
Each
Each
Each
Cubic Yard
Each
Each
Each
Each
Such payment is full compensation for furnishing all materials, equipment, labor, and
incidentals to complete the work as specified.