630 Traffic Signs and Sign Supports

Description (630.01)

This information is intended to serve as a guide for construction personnel where the Contractor furnishes and installs traffic control devices and appurtenances. It may also be useful for maintenance personnel performing the same functions. Inspection procedures for various types of traffic control devices are outlined, mainly in the form of checklists to assist project personnel in performing their duties. This information points out the various important features of each device and references the applicable specification or standard drawing. Illustrations are used for easy recognition of the device or feature being discussed.

Sign Service

Sign service shall comply with SCDs TC-32.10 and TC-32.11 and the plans. Additional information is provided in TEM Section 240-7.2 and C&MS Item 631.04. It consists of cable and equipment to provide a complete electrical service from either an underground source or an overhead direct drop to separately furnished disconnect switch with enclosure. The equipment could include a weatherhead, a conduit riser with necessary fittings, attachment clamps, and cable.  A thorough review of the plans should be made to determine the specific requirements of the maintaining agency for sign service.

When required, an electric meter base will be furnished by the applicable utility and installed by the Contractor as part of the sign service work.

The sign service shall terminate at the meter base if used; otherwise, termination shall be at the switch enclosure. Sign service may be:

1.      Direct drop by means of a weatherhead and conduit riser routed to the switch enclosure.

2.      Underground conduit and the pole interior to the enclosure.

3.      Underground and structure-attached conduit to the enclosure (for overpass mounted signs).

The conduit riser shall comply with Item 725 and the plans, and the weatherhead shall be threaded aluminum or galvanized ferrous metal 732.16.

The disconnect switch shall be a single-throw safety switch which meets the voltage and capacity requirements of the plans. The enclosure shall be a NEMA Type 4 ICS 1-110.15 with sufficient volume to accommodate an internal transformer when specified. The enclosure shall contain a solid neutral bar.

A ground wire shall be used as shown on SCDs TC-32.10 and TC-32.11 leading to a ground rod installed in accordance with TEM Section 240-7.3.

 

Sign Fabrication (630.04)

General

Signs should be inspected when received on the job site if possible, but certainly prior to erection.

The signs should be inspected for conformance with the plans, certified shop drawings, catalog cuts, and material specifications.

Flatsheet signs are typically of aluminum sheet cut into geometric shapes of the size specified.

Dimensions and thickness are to be as shown on SCDs TC-52.10 and TC-52.20. Bolt holes are to be drilled or punched (630.04).

Extrusheet signs are fabricated of aluminum sheet and extrusions, joined by spot welding and assembled by bolts (SCD TC-51.11). As an alternative, panels extruded in a single operation may be used (SCD TC-51.12). Extruded panels and spot welded panels shall not be used in the same sign. There shall be no appreciable deviation from flatness on the face of an assembled sign.

Overlay signs are of aluminum sheet of the specified thickness and used to cover the legend of extrusheet signs. Signs with overlays should be checked for any loose rivets holding the overlay sign.

All signs shall be reflectorized by being covered with the appropriate grade of sheeting. The sheeting shall be of the correct color, firmly attached, and free of tears, wrinkles, blisters, or blemishes.

Sign legend shall be in accordance with the plans, certified shop drawings, and the OMUTCD.

The type of copy on extrusheet signs shall be as shown on the certified shop drawings. Available types of copy are listed in TEM Table 297-6.

All signs shall be identified on the reverse side by decals as described in 630.

Extrusheet signs shall also to be identified by information in a detachable form on the back (see Item 630.04).

Sign Copy

TEM Table 297-6 provides information about the sign copy used, type, material used, design features, etc.

Sign Identification Decals

All signs shall be identified on the reverse side by decals of Type F white reflective sheeting (730.18) with silk screened numerals. Information shall be coded by screened-on or punched-out numerals before decal application and shall include sheeting manufacturer and year of sign fabrication. At the time of erection, month and year of erection shall be scratched out by the Contractor. This procedure is described in 630.04, which also contains an illustration of the decal. Decals for overlay signs may be on the front surface.

The following codes shall be used on the decals to identify the manufacturer of the sheeting.

0 - Avery Dennison

1 - Minnesota Mining and Manufacturing Company (3-M)

2 - Sakai Trading-New York, Inc.

3 - Nippon Carbide Industries (USA)

4 - Morgan Adhesives Company

5 - American Decal and Manufacturing Company

6 - Stimsonite Corporation

7 - Reflexite North America

 

Foundations (630.05)

Staking

Sign support foundations shall be located so the sign face is at a right angle to the roadway lanes served, unless the plans specify otherwise. An example of an exception is the W1-6 Large Arrow sign (black arrow on yellow background), which is located as shown in TEM Figure 298-24.

Foundations should be staked by the Contractor in accordance with the locations shown on the plans.

The stakeout locations should be checked for:

1.      The presence of obstructions which could restrict motorists' proper visibility of the sign from the point where they are expected to read the sign. Curved roadway locations should especially be checked.

2.      Obvious conflicts with overhead power lines or other utilities. There should be available a proper safe clearance from overhead lines for construction operations, in compliance with the National Electric Safety Code and any local codes.

3.      Possible conflict with underground facilities.

Foundation locations may be adjusted when necessary to overcome difficulties such as those shown in TEM Figure 298-24 and discussed herein with the concurrence of the project engineer. Adjustment should not violate minimum clearance dimensions as shown on SCDs TC-42.10 and TC-42.20 and the OMUTCD.

Excavation

Foundations shall be placed only in undisturbed soil or compacted embankment, and excavation shall be by an earth auger of the specified diameter to the specified depth. See TEM Figure 298-25 for a diagram of a foundation excavation.

If a minor cave-in should occur, the Contractor may continue excavation using an increased diameter or using sleeving, casing, or other method approved by the Project Engineer. The foundation concrete will be measured as determined from plan dimensions. The Contractor shall remove all extraneous material from the excavation before concrete placement.  When subsurface obstructions are encountered, permission may be granted by the Project Engineer to replace the excavated material and relocate the foundation.  When bedrock is encountered, the portion of the specified foundation depth within the bedrock may be reduced as much as 50 percent.

Placement

Anchor bolts and conduit ells shall be of the correct size and furnished with the support. At least one 2 inch (51 millimeters) minimum conduit ell shall be furnished and capped if unused. Anchor bolts, conduit ells, and EMT (Electric Metallic Tubing) shall be oriented in the foundation according to the plans, conduit runs, and ground rod location.  All anchor bolts shall be provided with standard steel hex nuts, leveling nuts, and plain washers.  The nuts shall be capable of developing the full strength of the anchor bolts.  Reinforcing bars, tie loops, and tie bars shall be of the correct size and arranged with the anchor bolts into cages according to the applicable SCD TC-21.10 or SCD TC-21.20.  A special foundation design will be required when soil with a load bearing capacity of less than 2,000 pounds per square foot (9700 kg/m˛) is encountered.

Anchor bolts shall be vertical with their ends projecting the correct distance above the foundation surface in compliance with the plans.  When the distance the anchor bolts project above the foundation surface is not specified, a rule of thumb is four times the bolt diameter.  The anchor bolts shall be tied to the cage tie bars according to standard details.

The rebar cage shall be supported 3 to 4 inches (75 to 100 millimeters) above the bottom of the excavation by a piece of concrete block or similar material. The cage shall be positioned with a clearance of 3 inches (75 millimeters) from the excavation wall by similar blocking so that after concrete placement a full thickness cover is assured.  A template and/or frame shall be used to rigidly hold the anchor bolts and conduit ells in the specified pattern during concrete placement. A form shall be oriented according to the plans to shape the foundation into a square from the surface or grade shown to a nominal 6 inches (150 millimeters) below ground line.  The template and form may be combined. Gaps of 6 inches (150 millimeters) or less between the foundation and adjacent paved surfaces shall be eliminated by increasing the formed foundation.

Water encountered in the foundation excavation shall be pumped out before concrete placement.

If this is not feasible, concrete should be placed by the tremie-tube method.

Concrete conforming to Item 499 and Item 511 shall be placed and vibrated to eliminate voids. Care should be exercised during vibrating to avoid disturbing the anchor bolts, conduit ells, and reinforcing cage.

Forms may be removed as soon as the concrete has hardened sufficiently so as not to be susceptible to damage, 511.16.

Minor earth caving external to the hole, which may have occurred during excavation using sleeving or casing should be corrected after concrete placement by backfilling and tamping in accordance with 203.

Joint filler complying with 705.03 shall be placed between the formed foundation and adjacent paved surfaces.

Supports and poles may be erected, signs installed, and span wire load applied only after the concrete has aged sufficiently to be in compliance with 630.

Curing and Loading

Curing and loading of concrete for traffic control devices shall comply with 511.17.

Concrete for foundations of sign supports shall be cured, have bracing removed, and be loaded only when the concrete has achieved the age shown below:

 

 

Age of Concrete in Days

 

Without Beam Test

With Beam Test **

Curing

7

5

Removing Bracing

7

3

Loading*

14

7

 

* No load shall be applied or other work done that will damage new concrete or interfere with its curing.

** Beam test specimens shall be poured from the same batch, immediately before, during, or after foundation pour. Specimen configuration shall be to ODOT requirements. Specimens when tested shall have at least an average modulus of rupture for two tests of no less than 650 pounds per square inch (4.5 MPa).

 

Sign Supports (630.06)

General

Various general aspects of overhead sign supports are addressed in this section. TEM Table 297-7 provides an overall summary of the structure types, allowable sign area on each, and the span or arm length.

Pole and Support Inspection

This inspection checklist covers the general features of strain poles, mast arm type signal supports, and overhead sign supports. Features pertaining only to specific pole or support types will be found in the sections of this manual covering exclusively those poles or supports.

1.      When poles and supports of the combination type are specified, they are to provide extra length for a highway lighting function, and welded-on bracket arm plate(s) complying with SCD HL- 10.12 or SCD HL-10.11 for attachment of a separately furnished luminaire arm. An upper handhole and an additional internal J-hook are to be furnished.

Figure 630.A

2.      Supports may be of an alternate design utilizing all non-tapered tubing structural members.

3.      If possible, poles and supports should be inspected when received, but certainly prior to erection.

4.      General dimensions should be checked first, including pole length, base diameter, top diameter, and wall thickness. Similar mast arm dimensions should also be checked. Wall thickness is most easily measured with calipers at the end. Caps on poles may have to be removed.

5.      Orientations of the various appurtenances should be checked against the plan’s orientation diagram if such is available; otherwise, orientations may be determined from certified shop drawings and the intersection drawing.

6.      Base plate dimensions should be checked including thickness, bolt circle diameter, and bolt hole size. Base plates may be plate or cast steel according to 730.04.

7.      A handhole with ground lug is to be furnished, with a cover plate complying with 730.05 and a stainless steel chain complying with 730.10.

8.      Blind half-couplings shall be provided where required. Sharp edges shall be rounded to prevent damage to cable or wires. Blind half-couplings shall be plugged when not in use. Couplings may be for signal or interconnect cable entrance or for attaching supports for traffic control equipment and for hubs for controller cabinets. Entrance couplings shall be threaded for use with threaded weatherheads.

9.      An internal J-hook shall be furnished and located as indicated on the plans.

10.  A pole cap conforming with 730.06 shall be furnished and in place before final inspection.

11.  An arm cap conforming with 730.07 shall be furnished for chords or mast arms.

12.  All strain poles and overhead sign and signal supports shall be grounded, even if no power is available.

13.  Welding and galvanizing shall be inspected in accordance with 630.

14.  Supports are to include sign brackets, U-bolts, and clamps. When required by the plans, supports are to include luminaire support arms, bracing rods, other necessary structural members, and signal hanger clamps with clevis.

15.  The correct number and size of anchor bolts and conduit ells shall be furnished for placement in the foundation.

16.  Anchor bolt diameter and length shall be according to the plans and SCD TC-21.10 or TC- 21.20. Anchor bolt ends may have an L-bend or be fitted with a tapped steel plate. Threaded ends shall not to be damaged and shall be galvanized at least 2 inches (50 millimeters) beyond the threads. The galvanizing should be in good condition, and absent or damaged galvanizing should be repaired by the application of two coats of zinc-rich paint. Galvanizing thickness should permit the turning of nuts by a wrench without difficulty. Loose rust on anchor bolts should be removed.

17.  All anchor bolts shall be provided with standard steel hex nuts, leveling nuts, and plain washers. The nuts are to be able to develop the full strength of the anchor bolts.

Inspection of Welds

All welds of supports shall be inspected visually, as soon as possible, following support delivery. Welds should be inspected for flaws and imperfections under good lighting conditions using a magnifying glass as necessary. Evidence of any of the following faults or other imperfections, such as warping and misalignment may be cause for rejection of the support. The following features of welds should be checked:

1.      A check should be made for the actual presence of all welds called for by the certified shop drawings and standard drawings.

2.      Welds on tapered tubes, pipe, or structural shapes shall be continuous around the joint. Welds requiring terminations shall be of the correct length.

3.      Welds shall not exhibit cracks or discontinuities in base metal or weld material and shall not show evidence of porosity, which shows up as pitting or pinholes. The galvanizing layer may cover such flaws, but their existence should be checked.

4.      Welds shall be full cross-sections without excessive concavity or convexity. Required weld terminations shall be filled to full section without depressions or craters.

5.      There should be no evidence of undercut, a condition where a shallow groove is melted into the base metal adjacent to a weld and left unfilled by weld metal.

6.      Base plates shall be welded to two ply poles with AWS prequalified welds in conformance with 730.04.

7.      Arm attachment plates shall be welded inside and outside with fillet welds. Each fillet weld shall be equal to the wall thickness of the respective tubing.

Inspection of Galvanizing

The galvanizing cover of supports shall be inspected visually, as soon as possible, following delivery. The galvanizing should be inspected externally and internally for flaws and imperfections in daylight or strong artificial light. In accordance with 513.26, supports shall be loaded, transported, unloaded, stored, and erected in a manner to avoid damage to any feature including the galvanizing. Supports stored in the field should be kept off the ground to prevent the galvanizing from contacting water, which may result in a premature oxidation condition. The galvanizing should have the appearance of a uniform application. Supports should be checked for assurance that the following flaws or imperfections do not exist:

1.      Loose or bare spots in the galvanizing where improper preparation has prevented metal adherence in the molten zinc bath. Poles should be rejected if the point of a penknife can flake off the galvanizing layer.

2.      General overall roughness, a symptom of over-pickling or of excess zinc bath temperature and/or immersion time.

3.      Pimples, due to entrapped bath scum particles.

4.      Blisters, due to hydrogen gas absorbed during pickling and coming out at the time of galvanizing.

5.      Flux inclusions, picked up from the top of the bath when dipping and burnt-on during immersion.

6.      Ash, usually in course lumps picked up from the top of the bath.

7.      Patches of dull gray coating due to the slow cooling of heavier cross-sections of supports after immersion.

8.      Excess zinc lumps or runs due to delayed molten metal run-off from surface discontinuities, such as joints, seams, or holes.

9.      Rust stains due to the weeping of impurities from the pickling process at seams and folds.

Excessive galvanizing faults and imperfections combined with general poor workmanship may be cause for rejection of the support. Gross imperfections may lead to the suspicion of inadequate protective cover which may require inspection with a magnetic instrument. Items 1 through 6 may be cause for rejection. Items 7 through 9, if extreme, may be cause for rejection because of poor appearance, even if the protection of the support is not affected.

After erection, supports should be given a final inspection for any damage to the galvanizing due to improper handling in the erection process. Damage due to slings, etc., which is more serious than superficial brightening, is to be repaired by the Contractor with the application of two coats of zinc-rich paint.

Weight of Supports

TEM Tables 297-8a through 297-8f provide information on the weight of various overhead sign supports. For all structures, the weight of the pipe support has been given where pipe has been frequently used in place of tapered tubes. In general, the tapered tube support will be lighter than the pipe support. The support numbers listed may be preceded by I-129, 815, 844, or other designation instead of TC.

For estimating purposes, a 10 x 10 foot (3.0 x 3.0 meter) sign, excluding the sign lighting, weighs approximately 250 pounds (113 kilograms).

Assembly and Erection Procedure

Erection procedures pertaining to specific pole or support types will be found in the sections of this manual devoted exclusively to those poles or supports. In general, the following assembly and erection procedure applies:

1.      To minimize erection time and the hazard to workers and road users where traffic is maintained, supports should be erected with mast arms attached, and horizontal sign support members (over the roadway) should be prewired for lighted signs or other traffic control devices. See the notes in plans for traffic maintenance requirements when span-type sign support members are erected.

2.      Support components shall be assembled with their threaded fasteners tightened in accordance with 630.06. Fasteners 1/2 inch (13 millimeters) or greater shall have anaerobic adhesive applied to the threads according to the manufacturer’s recommendations. Nuts shall be tightened by the turn-of-the-nut method.

3.      The turn-of-the-nut method shall be in accordance with 513.20. Nuts shall be made snug tight by the effort of a person using an ordinary spud wrench followed by an additional 1/12 to 1/6 turn.

4.      Leveling nuts shall be placed on the anchor bolts, initially clearing the foundation surface by at least 1/4 inch (6 millimeters) and forming a horizontal plane.

Figure 630.B

5.      Poles or supports shall be raised into position with equipment of adequate lifting capacity and used in a manner preventing damage to attached appurtenances (signs, brackets, luminaries, etc.) and to the galvanizing. The weight of poles or supports is given in TEM Tables 297-8a through 297-8f for the use of the Contractor in the erection procedure.

6.      With the pole or support’s base plate resting on the leveling nuts, the plain washers and anchor nuts shall be placed on the anchor bolts, the support plumbed in a vertical position or raked, and anchor nuts given a preliminary tightening.

7.      After any necessary leveling, nut adjustments are made to ensure that supports are essentially vertical after attachment of signs, sign lighting equipment, or signals. The anchor nuts shall have anaerobic adhesive applied and be tightened in accordance with the instructions for assembling fasteners given in the foregoing paragraphs, 2 and 3.

8.      Anchor nuts are not to be covered with bolt covers or a cover base regardless of support location (Item 630.06B).

9.      Poles or supports which are prewired before erection should be checked to determine if the erection procedure has disturbed the wiring. Wire for lighted signs should be supported by looping wire over the J-hook in the vertical support member (Item 631.05). Cable supported by cable support assemblies should be checked to determine if the sling is over the J-hook and if the adjustment is proper to eliminate strain on the cable jacket.

Overhead Sign Supports by Type

General

The previous section addressed general assembly and erection guidelines for strain poles and supports. The following sections provide additional information specific to various types of supports. For the most part, the information is provided in checklist format.

Ground-Mounted Sign Supports (630.06.A)
General

This section provides additional information, generally in the form of checklists, about various ground-mounted supports. TEM Section 221 addresses general guidelines about sign supports and TEM Section 240-5 provides additional design information about ground-mounted supports.

Posts

1.      Ground-mounted sign supports of the post type shall be U-channels or square posts of the number specified and shown on SCD TC-41.20.

2.      Post lengths appearing on the plans are approximate and the Contractor is responsible for determining the exact length of required posts before cutting to length (630.06.A).

3.      No. 4 U-channel posts consist of two No. 2 posts bolted back-to-back. No. 6 U-channel posts consist of two No. 3 posts bolted back-to-back. Back-to-back posts are assembled by 5/16-inch (8 millimeters) steel bolts, lock-washers, and nuts on 4-inch (100 millimeters) centers below the ground line and 16 inch (400 millimeters) centers above the ground line.  No. 4 and No. 6 U-channel posts cannot be installed in exposed locations.

4.      Posts should have a line of paint 48 inches (1.20 meters) from the end, which will be in the earth. The mark when driven to a distance of 6 inches (150 millimeters) above the ground indicates a post driven to the proper depth.

5.      If it is necessary to cut posts to correct length in the field, the cut end should be covered with two coats of zinc-rich paint and the cut end driven in the earth or embedded when required (except for back-to-back posts).

6.      Posts shall yield when hit and shall be driven to a depth of 42 inches (1.05 meters). Posts are typically not to be embedded in concrete unless specified in the plans or ordered by the Project Engineer to overcome problems, such as adverse soil conditions or prevalent bedrock close to the surface. The driven depth has been established to ensure best yielding characteristics. Deeper depths are not beneficial in this regard.

7.      Caution shall be used when driving posts in areas of buried cable.

8.      Posts shall not to be driven in drainage ditches.

9.      Posts shall be installed vertically and at right angles to the edge of pavement, unless otherwise required. Exceptions may be NO PARKING signs and STOP signs located at intersections with curved approaches. In this situation, STOP signs should be placed perpendicular to a line from the viewing point where they are normally recognized and stopping action would begin.

10.  Posts shall be driven without bending, distortion, or end mutilation. Mutilation may be prevented by the use of a driving cap. Posts should be checked to see if the paint mark is 6 inches (150 millimeters) out of the ground after driving.

11.  Posts located in paved areas shall be driven through a hole provided by sleeving or core drilling. After driving, the hole shall be patched with asphalt concrete or approved bituminous material.

12.  At locations where posts cannot be driven, the post may be moved at no additional cost to ODOT, when approved by the Project Engineer.

13.  Typical vertical and horizontal clearances of signs are shown on SCDs TC-42.10 and TC- 42.20.

“One Way” Sign Supports

Square posts, which are capable of supporting signs at right angles to other signs on the post, are designated as “One-Way” sign supports for the most common application. This is shown on SCD TC-41.50.

Standard Beams

1.      Ground-mounted sign supports of the non-breakaway beam type shall be rolled steel, wide flange sections of the size, and weight specified (from the list on SCD TC-41.10). Non-breakaway beams shall be protected by guardrail or concrete barrier installed for another purpose. Inspection of beams of the breakaway type is covered in 630.

2.      Beam lengths appearing on the plans are approximate and the Contractor is responsible for determining the exact length of required beams before fabrication (630.06 A).

3.      Galvanizing shall be inspected in accordance with 630.

4.      Beams shall be embedded in a concrete foundation in accordance with SCD TC-41.10.

5.      Beams shall be raised into position with equipment of adequate lifting capacity and in such a manner as to prevent damage to the galvanizing. The beams shall be braced in a plumb and square position until the concrete has cured. The age of the concrete before it is considered cured and before signs are permitted to be erected is to be in accordance with 630.

Breakaway Beams and Connections

1.      Ground-mounted sign supports of the breakaway beam type shall be rolled steel, wide flange sections of the size, and weight specified (from the list on SCD TC-41.10).

2.      Beam lengths appearing on the plans are approximate and the Contractor is responsible for determining the exact length of required beams before fabrication (630.06 A).

3.      Beams shall use a slip base design. Alternate designs of breakaway connections are permitted.

4.      Base plates shall be fabricated to standard details and welded-on with a bead equal to the beam flange and web thickness respectively, but not less than 1/4 inch (6.4 millimeters).

5.      Welding and Galvanizing shall be inspected in accordance with 630.

6.      All portions of beams should be shop assembled in accordance with SCD TC-41.10.

7.      The beam upper portions shall be joined by the bolts attaching the fuse and hinge plates. The plates shall be fabricated to standard details with the fuse plate having notched holes at the bottom and the hinge plate having unnotched holes. The steel hex head bolts, with washers under both head and nut, shall be tensioned in the shop to the final specified value.  For S4x7.7 (S100x11.5) beams only, malleable iron beveled washers are used under bolt head and nuts.

8.      Torque limiting nuts may be used instead of conventional nuts on the fuse and hinge plates (SCD TC-41.10, Note 5).

9.      The beam lower portions should be joined by steel hex head bolts inserted with their nuts uppermost. A galvanized bolt retainer plate shall be sandwiched between the base plates. Flat washers shall be used under both bolt head and nut as well as under the bolt retainer plate. Bolts shall be snug tightened for delivery to the site with final torqueing to be done after erection.

10.  Torque limiting nuts may be used instead of conventional nuts on the base plates (SCD TC-41.10, Note 5). The nuts shall be snug tightened, but not to the point where the upper area shears away.

11.  Base plate skewed notches should point toward the roadway along the path of typical vehicle collision. The skewed notches of both base plates should match.

Figure 630.C

12.  For beams located in medians, the base plates should be welded-on upside down as compared with those of beams located on the right side of the roadway, so the base plate skewed notches will point toward each roadway along the path of vehicle collision from either direction of traffic.

13.  For beams located in medians, fuse plates shall be used on both sides of the beam.

14.  For beams located on the right side of the roadway, fuse plates shall be on the side of the beam facing traffic.

Figure 630.D

15.  For the alternate design, special foot brackets shall be bolted to the upper beam portion, and four couplings incorporating a breakable reduced section are connected between the foot brackets and threaded anchor inserts embedded in the foundation. The couplings permit use of the design in medians where collision can occur in either direction of traffic.

16.  The alternate design uses four hinge/fuse plates incorporating a thinned section and bolted where the beam is cut through just under the sign. The pair of plates on the impact side of the beam and a pair on the opposite side bend severs upon impact to allow the beam to swing upward out of the path of the impacting vehicle.

17.  Beams should be erected in a single unit because they are easier to plum, square, and brace when the entire assembly is raised and set in concrete.

18.  Beams shall be erected in accordance with the procedure given for non-breakaway beams in 630.

19.  A sloping concrete foundation top surface is required on the high ground side to prevent a water pooling pocket and permit drainage as per SCD TC-41.10. For the alternate design, the foundation top shall be level in the area of the breakable couplings.

Figure 630.E

20.  When a supplemental panel is required below an extrusheet sign, the panel is fastened by sign backing assemblies to the parent sign. The panel shall be separated from the sign by the width of the fuse plate, plus 1 inch (25 millimeters). This is to permit unhindered hinge plate bending in the event of a vehicle collision.

21.  After the foundation concrete is cured, base plate nuts shall be loosened in turn and retightened with a torque wrench in a systematic manner to the specified maximum torque shown in the table on SCD TC-41.10, also shown in TEM Table 297-9. Torque wrenches used should be calibrated daily.

22.  When torque limiting nuts are used on base plates, the nuts shall be loosened in turn, and tightened in a systematic manner until the upper area shears away and ensures that the correct torque has been applied.

23.  At least 4 weeks following the erection of signs on breakaway beams, the breakaway feature shall be inspected by the Contractor for evidence of shifting or loose fasteners.

24.  All loose fasteners shall be re-torqued to specified values. Base plate fasteners shall be loosened and re-torqued even if no shifting or looseness is detected. If the base plate connection was made with torque limiting nuts, re-torqueing will only be required if looseness can be detected. Re-torqued conventional nuts shall have anaerobic adhesive applied, or as an alternate, new torque limiting nuts of the proper range may be used.

Rigid Overhead Supports (630.06.B)
Single Arm Support

1.      Single arm supports shall comply with certified shop drawings, SCD TC-16.20, and the plans.

2.      Welds, galvanizing, and general features of the support shall be inspected in accordance with 630.

3.      For arms of two telescoping pieces, a 15 inch (400 millimeters) overlap is required. The overlapped arms shall be secured with a stainless or galvanized steel hex head through bolt with nut.

4.      Arm caps shall cover at least 50 percent of the end area (Item 730.07).

5.      A minimum of two brackets shall be provided for each sign, each attached to the arm by steel clamps with carriage bolts. The clamps should be able to be tightened in a manner to firmly grasp the arm so as to prevent sign rotation.

6.      If signs are lighted, disconnect switch enclosure mounting brackets may be required on the support.

7.      Erection shall be in accordance with the general procedure given in 630, except as hereafter noted.

a.       The Contractor may choose to attach the signs and any sign lighting items before erection.

b.      Signs are installed at the same elevation. For this purpose, adjustment is provided by two pairs of slotted holes in the sign bracket for attachment of the arm clamp.

c.       Contact between galvanized clamp flanges and aluminum sign brackets shall be prevented by the use of chloroprene gaskets.

d.      Initial rake shall be adjusted so that under the load of signs, the pole will assume an essentially vertical position and the arm rise will be within the limits specified on the standard drawing, 3 inches (75 millimeters) minimum and 12 inches (300 millimeters) maximum.

 Cantilever Support

1.      Cantilever supports shall comply with certified shop drawings, SCD TC-12.30, and the plans.

2.      Welds, galvanizing, and general features of the support shall be inspected in accordance with 630.

3.      Supports with arm lengths 18 feet (5.5 meters) and over shall have truss members. Truss members may be angles or pipe.

Figure 630.F

4.      One blind half coupling shall be welded to the top chord approximately 12 inches (300 millimeters) beyond or outside of the first sign bracket for a sign less than 20 feet (6.1 meters) long. A second blind half coupling shall be welded near the second sign bracket for signs 20 feet (6.1 meters) or longer.

5.      Erection shall be in accordance with the general procedure given in 630, except as hereafter noted.

a.       The Contractor may choose to attach the signs and any sign lighting items before erection.

b.      Signs are centered vertically on the chords.

Center-Mount Support

1.      Center-mount supports shall comply with certified shop drawings, SCD TC-9.30, and the plans.

2.      Welds, galvanizing, and general features of the support shall be inspected in accordance with 630.

3.      Sign clearance above the roadway shall be a minimum of 17 feet (5.2 meters).

4.      Arms may be either square or round tube. The arm attachment design shall be in accordance with standard details for either square arms or round arms with separate cradle.

5.      A blind half coupling shall be located on the pole.

6.      Erection shall be in accordance with the general procedure given in 630, except as hereafter noted.

a.       Signs are centered vertically on the arms.

b.      Signs may be mounted laterally on the support in an eccentric position. However, a minimum of 2 feet (0.6 meter) of sign length shall remain to one side of the pole centerline.

c.       The Contractor may choose to attach the sign and any sign lighting items before erection.

 Semi-Overhead Support

1.      Semi-overhead supports shall comply with certified shop drawings, SCD TC-9.10, and the plans.

2.      Welds, galvanizing, and general features of the support shall be inspected in accordance with 630.

3.      Sign clearance above the ground shall be at least 10 feet (3.0 meters) unless a lower height is approved by the Project Engineer to provide sign visibility through preceding overpass structures.

4.      Arms may be either square or round tube. The arm attachment design shall be in accordance with standard details for either square arms or round arms with separate cradle.

5.      A blind half coupling shall be located on the pole.

6.      Erection shall be in accordance with the general procedure given in 630, except as hereafter noted.

a.       Signs are centered vertically on the arms.

b.      Signs may be mounted laterally on the support in an eccentric position. However, a minimum of 2 feet (0.6 meter) of sign length shall remain to one side of the pole centerline.

c.       The edge of the sign shall be back at least 2 feet (0.6 meter) from the edge of the curb.

d.      The Contractor may choose to attach the sign and any sign lighting items before erection.

 Span Truss Support

1.      End frames for span truss supports shall comply with certified shop drawings, the plans, and SCD TC-7.65 for aluminum trusses and SCD TC-15.115 for steel trusses.

2.      Welds, galvanizing, and general features of the support shall be inspected in accordance with 630.

3.      Handholes shall be oriented on the end frame downstream vertical member on the side away from the direction of traffic.

4.      The size of truss members shall be in accordance with standard details. Truss member joints may be of two different designs.

5.      Switch enclosure mounting brackets shall be in place and a chase nipple installed on both end frame vertical members, which are away from the direction of traffic.

6.      An angle shall be furnished and welded onto the end frame, near the top, to support the lower chords of the span box. Stainless steel U-bolts shall be used with aluminum trusses and galvanized steel U-bolts with steel trusses.

7.      End frame vertical members shall be furnished with steel clamps and a separate tee or angle (alternate) for supporting the upper chords of the span box. Stainless steel U-bolts shall be used with aluminum trusses and galvanized steel U-bolts with steel trusses.

8.      An internal J-hook shall be in each end frame in the downstream vertical member.

9.      When using an aluminum truss, the following shall apply:

a.       Aluminum trusses shall comply with certified shop drawings, SCD TC-7.65, and the plans.

b.      Welds shall be inspected according to 630.

c.       End caps shall be on each end of chords. The top front end caps shall be tapped for wiring.

d.      A blind half coupling shall be welded to the front top chord of the truss approximately 12 inches (300 millimeters) beyond or outside of the first sign bracket for each sign. Sharp edges shall be rounded to prevent damage to wires.

e.       Span length shall be in accordance with shop drawings and the plans.

f.       Span box camber shall be in accordance with standard details.

g.      Flanges between span box sections may be cast or fabricated with forged flanges as an alternate.

h.      Flange attachment hardware shall be stainless steel bolts and nuts.

i.        Supports shall be furnished with necessary sign brackets, U-bolts, luminaire support arms, bracing rods and other necessary structural members

10.  When using a steel truss, the following shall apply:

a.       Steel trusses shall comply with certified shop drawings, SCD TC-15.115, and the plans.

b.      Steel truss checking instructions are the same as those for aluminum trusses, except as hereafter listed.

                                                              i.      The galvanizing shall be inspected according to 630.

                                                            ii.      Flanges between span box sections shall be forged.

                                                          iii.      Flange attachment hardware shall be galvanized steel bolts and nuts.

11.  See the notes in the plan for traffic maintenance requirements when span type sign support members are erected.

12.  The base plates of end frames shall be placed on anchor bolt leveling nuts, plain washers and anchor nuts placed, the frames plumbed into a vertical position in both longitudinal and lateral directions, and nuts made tight in accordance with 630.

13.  Truss camber shall be correct. The various truss sections shall be assembled in the arrangement and sequence shown on the shop drawing.

14.  Trusses may be assembled into a total span while lying on blocks with wedges. Flanges on truss section ends may be aligned by driving in the wedges as necessary. All flange bolts are then assembled and made tight.

15.  Two cranes may be necessary when lifting very long trusses or the heavier steel trusses. For reference, truss weights are given in 630.

16.  Care should be taken in the attachment of slings. Trusses should be lifted at positions of a quarter to a third of the total span. Slings should be attached to the top chords and the horizontal diagonals.

Figure 630.G

17.  Trusses may be easily overstressed by poor handling, and care should be taken when moving assembled trusses for temporary storage, during transportation to the erection location, and in the erection procedure.

18.  Trusses shall not be erected unless at least one sign is in place within 8 hours or the trusses are fitted within the same period with damping devices approved by the Project Engineer (630.06 B).

19.  Attachment of the box truss to the end frames shall be by four U-bolts. Aluminum trusses shall be attached by 5/8-inch (16 millimeters) stainless steel bolts according to SCD TC-7.65 and steel trusses shall be attached by 3/4-inch (19 millimeters) galvanized steel bolts according to SCD TC-15.115.

20.  The Contractor may choose to attach the signs and any sign lighting items before erection.

21.  Signs are centered vertically on the chords (not considering the height of Exit Panels).

Span Wire Support (630.06.C)

Span Wire sign supports shall comply with SCD TC-17.10 and the plans. These sign supports consist of strain poles, messenger wire with accessories, and sign hangers. Strain pole size and type, anchor base, or embedded shall be as specified.

1.      Strain poles shall be inspected in accordance with 632 and general features of the poles shall be inspected in accordance with 630. Welds shall be inspected according to 630 and the galvanizing shall be inspected according to 630.

2.      Erection shall be in accordance with the general procedure given in 630, except as hereafter noted.

a.       For the initial rake of strain poles of the anchor base type or embedded type poles, see 632.

b.      The upper messenger wire shall be assembled with its accessories according to the standard drawing. Preformed guy grips are not permitted because wind loads on the signs can cause failure of the grips. Alternate methods of attaching messenger wire to strain poles may be used.

                                                              i.      Span wire clamp with clevis, anchor shackle and thimbles on the messenger wire, or

                                                            ii.      Messenger wire wrapped twice around the strain pole and secured with a 3 bolt clamp of the proper size.

c.       The upper messenger wire shall be fitted with its signs, furnished under other items of work, and the vertical clearance to sign bottoms adjusted within clearance limits over the roadway. The sag of the upper messenger wire shall be between 4 and 5 percent.

d.      It is essential that the lower messenger wire have more slack than the upper wire. The sag should be approximately 3 inches (75 millimeters) greater than the upper wire. This sag adjustment shall be made before the sign hangers are attached to the lower wire.

e.       Sign hangers shall be clamped snugly to the lower wire by U or J bolts. In the case of back-to-back signs, the lower messenger wire running in between the sign hangers is clamped between bolted spacers that are slightly thinner than the messenger wire (see SCD TC-17.10).

Overpass Structure Mounted Support (630.06.D)

1.      Overpass structure-mounted supports shall comply with the plans and SCD TC-18.24 for flush type supports and SCD TC-18.26 for skewed type supports.

2.      Overpass structure-mounted supports include sign brackets and two different kinds of steel Z-bars which are fastened to bridge concrete. For steel beam bridge mounting, aluminum angles at the bottom are to extend between sign brackets and short galvanized steel angles bolted to the bridge steel. For overpass structures essentially perpendicular to the roadway underneath, sign brackets are flush mounted to Z-bars for direct sign viewing. For overpass structures skewed to the roadway underneath, a wedge-shaped box structure is inserted between the sign brackets and Z-bars to provide for direct sign viewing.

3.      The number of sign brackets will vary according to the bracket spacing as required by SCD TC-22.20. Bracket details are also shown on the standard drawing.

4.      The number of aluminum frames in skewed supports shall equal the number of sign brackets. Frame details shall be in accordance with standard details and are to include two angles placed diagonally.

5.      Front upper and lower members of skewed supports shall be aluminum angles with a length equal to the sign length.

6.      The skewed support structure shall be internally braced by two aluminum angles extending diagonally and horizontally through the interior.

7.      For bridge clearance above a roadway of less than 17 feet (5.2 millimeters), the sign clearance above the bottom of the bridge shall be 3 inches (75 millimeters) minimum without or 15 inches (400 millimeters) minimum with sign lighting fixtures on the lower edge of the sign.

8.      Supports shall be mounted on the overpass structure so the sign is horizontal regardless of bridge slope (630.06 D).

9.      Expansion double wedge steel anchor bolts shall be used to fasten the support’s Z-bars to the overpass structure concrete parapet. Intended locations of anchor bolts are to be approved by the Project Engineer before any field drilling. Z-bars “A” are used at the top and Z-bars “B” at the bottom of parapet concrete.

Figure 630.H

10.  For a steel beam bridge mounting, aluminum angles at the bottom shall be fastened to short galvanized steel angles bolted to the bridge steel.

11.  Chloroprene gaskets shall be used to prevent contact between aluminum sign brackets or support frames and steel Z-bars or bolted-on angles.

12.  If the sign extends more than 4 feet (1.2 meters) above or below the attaching Z-bars, intermediate sign brackets shall be provided.

13.  For precast beam bridges, aluminum angles at the bottom shall be fastened to short steel angles and two expansion double wedge steel anchor bolts shall be used.

14.  After sign erection, the sturdiness of the support to bridge attachment should be checked.

 

Sign Erection (630.07)

General

This section provides information on erection of the signs. Assembly and erection of various types of overhead sign supports are addressed in 630.04 and 630.05 and ground-mounted supports are addressed in Section 630.06.

Ground-Mounted Flatsheet Signs

When erecting ground-mounted flatsheet signs, the following provisions apply:

1.      Typical vertical and lateral clearances of ground-mounted flatsheet signs are shown on SCD TC-42.20.

2.      Flatsheet signs shall be fastened to posts by 5/16-inch (8 millimeters) hex head steel bolts with a 3/8-inch (10 millimeters) ID x 1-1/4-inch (32 millimeters) OD wide washer under the bolt head and using a lock washer and hex nut. For U-channel posts, at each bolt, a bearing plate shall be used behind the sign to reinforce the sign, as indicated on SCD TC-41.20. The hardware and bearing plates are furnished with the signs.

3.      Posts supporting groupings of flatsheet signs in multiple arrangements will require the use of sign backing assemblies made up of bolted together short sections of posts. Sign backing assemblies are furnished with the signs unless separately itemized.

4.      Flatsheet signs mounted so as to be read by motorists using bridges shall be erected on special steel posts in accordance with SCD TC-41.40.

5.      Street Name signs shall be erected on square supports in accordance with SCD TC- 41.40.

Ground-Mounted Extrusheet Signs

When erecting ground-mounted extrusheet signs, the following provisions apply:

1.      Typical vertical and lateral clearances of ground-mounted extrusheet signs are shown on SCD TC-42.10.

2.      Mounting clips and other attachment hardware shall conform with SCD TC-51.11.

3.      Supplemental panels erected underground-mounted extrusheet signs mounted on non-breakaway beams shall be fastened directly to the beams. The panel shall be separated from the parent sign by 1 inch (25 millimeters) to conform with SCD TC-42.10. When the panel is too short to reach between the beams, the panel may be fastened to the parent sign by sign backing assemblies.

4.      Supplemental panels erected underground-mounted extrusheet signs mounted on breakaway beams shall be fastened to the parent sign by sign backing assemblies. The panel shall be separated from the parent sign by the width of the fuse plate plus 1 inch (25 millimeters).

5.      Exit Panels erected above extrusheet signs shall be attached by sign backing assemblies furnished with the Exit Panel.

6.      The signs should be checked after erection to verify that the beams extend to the top of the signs and that the signs are horizontal and the clearances satisfactory.

Overhead Signs

When erecting overhead signs the following provisions apply:

1.      The clearance above the roadway for the bottom of overhead signs shall be a minimum of 17 feet (5.2 meters) or as shown on the plans.

2.      Overhead signs shall be vertical or horizontal regardless of the sag of supporting messenger wire, mast arm rise, chord camber, or overpass slope.

3.      Signs erected on span wire supports shall be attached in accordance with SCD TC- 17.10.

4.      Signs erected on single arm supports (SCD TC-16.20) shall be installed so their bottom edge is at the same elevation. Sufficient adjustment for this purpose is provided by the two pair of slotted holes in the sign brackets for the attachment of the arm clamps. The clamps shall be tightened sufficiently to prevent sign rotation about the arm.

5.      Signs mounted on semi-overhead supports (SCD TC-9.10) shall be erected so that their edge clearance from the curb line is at least 2 feet (0.6 meter).

6.      Extrusheet signs over 8 feet (2.4 meters) in height may be delivered in two pieces for assembly in the field (630.08).

7.      Extrusheet signs erected on supports with two arms shall be centered vertically.

8.      Mounting clips and other attachment hardware for extrusheet signs shall conform to SCD TC-51.11.

9.      Signs mounted on center-mount supports (SCD TC-9.30) may be mounted laterally on the support in an eccentric position when required by the plans. However, a minimum of 2 feet (0.6 meter) of sign length shall remain to one side or the other of the vertical member centerline.

10.  Overlay signs erected in the field over existing extrusheet signs shall be attached by blind rivets at spacings as required in 630.04.

11.  Flatsheet signs used in connection with signals supported by span wire shall be fastened to the messenger wire by special attachments in accordance with SCD TC-41.41.

12.  Flatsheet signs used in connection with signals supported in a swinging condition on mast arm supports shall be fastened to the arm by a special attachment in accordance with SCD TC-41.41.

13.  Exit Panels erected above extrusheet signs shall be attached by sign backing assemblies furnished with the Exit Panel.

14.  Extrusheet signs shall be attached to rigid overhead supports using sign brackets in accordance with SCD TC-22.20.  Signs extending more than 4 feet (1.2 meters) above or below an attachment point require the use of intermediate sign brackets.

 

Sign Shipment and Storage (630.08)

Signs shall be suitably protected and identified for shipment and storage. Extrusheet signs shall be kept rigid by backbracing or crating and the sign face covered with protective material. The backbracing shall extend sufficiently below the sign lower edge to keep the sign off the ground.

Extrusheet and flatsheet signs shall be stored in a vertical position.

Signs must be stored in such a manner that the packaging paper or cardboard material does not get wet. If the packaging material or slip sheeting should become wet, the paper should be removed immediately from contact with sign faces to prevent damage to reflective sheeting on the faces.

In the case of signs furnished by ODOT for erection by the Contractor, the Contractor shall be responsible for the storage and care of the signs after their transfer (630.08).

 

Sign Inspection (630.13)

After sign erection, the Contractor shall inspect all signs under both day and night conditions. Any necessary adjustments in lateral position or orientation to correct visibility deficiencies shall be made to the satisfaction of the Project Engineer (630.13).

Overhead Guide Signs should typically be centered over the lane(s) to which they apply. Down arrows on the signs should normally be centered over the proper lane as viewed by the road user.

The maximum displacement of a down arrow from the center of a lane should not be more than 2 feet (0.6 meter).

Overhead Guide Signs situated on curved roadways and incorporating down arrows may have the arrow(s) adjusted within the sign and/or the entire sign moved laterally so the arrows, when seen from a typical viewing distance on the curve, will appear to be over the proper lane(s).

Night conditions inspection is to assure that each sign has visible and uniform reflectivity. Any signs not having proper reflectivity should be noted and cleaned or replaced by the Contractor.

 

Documentation Requirements – 630 Traffic Signs and Sign Supports

1.      Ensure signs and supports are in compliance with plans and approved catalog sheets.

2.      Document depth, diameter, or foundations.

3.      Document steel and clearance maintained (if used).

4.      Document support stubs (if placed).

5.      Document anchors: diameter and depth (if used).

6.      Document size and depth driven of drive post used.

7.      Document curing used on concrete.

8.      Measure appropriate units for foundations and/or supports used and turn in for pay.

9.      Document type, size, background sheeting, and legend sheeting for signs.

10.  Measure signs and turn in for pay as per 630.14.