Traffic Engineering Manual Volume 2
Chapter 6: Side Mounted Signs - Installation
Traffic Engineering Manual Volume 2, Chapter 6 – Edition 4
May 2014
1
Amendment Record
Ed/Rev No
Page(s)
Issue Date
Amendment Description
Ed 1
All
July 1986
Original Manual
Ed 2
(VicRoads only)
All
April 2000
Initial draft for comment
Ed 3
All
December 2001
New Edition
May 2014
Minor update including the discontinuation of slip base
strutted aluminium sign post system
Ed 4
(Document reference no. 2474753)
Traffic Engineering Manual Volume 2, Chapter 6 – Edition 4
May 2014
2
Contents
6.1 Procedure for Determining Post and Fittings Requirements ........................................................................ 4 6.2 Post Selection.................................................................................................................................................... 5 6.2.1 Number and Spacing of posts ........................................................................................................................ 5 6.2.2 Post Type and Size ............................................................................................................................................ 5 6.2.3 Determination of Post Length .......................................................................................................................... 9 6.3 Fitting Selection ............................................................................................................................................... 10 6.4 Special Procedures ......................................................................................................................................... 12 6.4.1 Posts in Sockets .............................................................................................................................................. 12 6.4.2 Single Post Mounting for Large Signs ........................................................................................................... 12 6.4.3 Joint-use Supports for Side Mounted Signs ................................................................................................. 13 6.5 Colour of Sign Supports ................................................................................................................................. 14 Appendix 6A Design Standards for Single Post Mounting of Large Signs ........................................................ 15 6A.1 General ............................................................................................................................................................. 15 6A.2 Post Size Selection Procedure ....................................................................................................................... 15 6A.3 Channel Size Selection Procedure ................................................................................................................. 15 6A.4 Maximum Sign Area and Typical Drawing..................................................................................................... 15 Traffic Engineering Manual Volume 2, Chapter 6 – Edition 4
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6.1 Procedure for Determining Post and Fittings Requirements
To determine the required posts and fittings for a side-mounted sign, proceed as follows:
•
Locate the sign precisely, both laterally and longitudinally, see Sections 5.2 and 5.4, and obtain ground levels under
the sign relative to the nearest edge of carriageway,
•
Determine the mounting height relative to the carriageway edge, see Section 5.3, and calculate the height of sign
above ground level,
•
Determine the number of posts required; see Section 6.2.1, noting that up to four posts may be used for very wide
signs,
•
Determine the post type and size required, see Section 6.2.2,
•
Calculate the overall length of post required, see Section 6.2.3, also Section 2.5,
•
Determine the type and number of fittings required, see Section 6.3.
Note also that special procedures (see Section 6.4) are applicable in certain cases.
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6.2 Post Selection
6.2.1
Number and Spacing of posts
The number of posts used to mount signs is as follows:
•
Single Post Mounting
o
square or rectangular signs up to 900 mm wide,
o
diamond signs with side dimension up to 900 mm (i.e. C size).
See also Section 6.4.2 regarding single post supports for large signs.
•
Two Post Mounting
o
all signs wider than 900 mm or a C size diamond sign, except as noted below, or in Section 6.4.2.
The spacing of posts is desirably 0.6 times the sign width.
•
Three Post Mounting
o
acceptable alternative to two posts mounting for signs 3.65 or wider.
The spacing is 0.45 times the sign width (1.6 m minimum).
Note that for wide signs it will frequently be more economical and less hazardous to use three posts of smaller
cross-section than two larger posts.
•
Four Post Mounting
o
6.2.2
applicable only to very wide signs, 4.5 m or wider. The minimum post spacing should be 1.3 m.
Post Type and Size
Details of standard post types and sizes, and the purposes, for which each is used, are given in Table 6.1.
To determine the size and type of post required, refer to Figure 6.1. Post types shown to the left of the graph
may be used wherever the sign is in a protected position, i.e. behind guard fence, on a cut batter where
permitted in Section 5.2, or elsewhere where it is unlikely to be struck by an out-of-control vehicle. For signs in
exposed positions, the types shown to the right of the graph should be used.
Frangible hardwood posts are illustrated in Figures 6.2.
Slip base strutted aluminium sign post system has been discontinued for use in Victoria. VicRoads is currently
investigating alternative options to the use of the slip base strutted aluminium sign post system. For interim options,
please contact Manager Network Standards on (03) 9854 2417.
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5
POST TY PE
NORMAL U S AG ES
ST AND AR D
LEN G T H
DEP TH I N G R OU ND (1)
BREA KA WA Y
32 NB gal tube
(2.0 wall)
Note (2) & (5)
Low mounted hazard
marker, Section
22.2.1
1625 mm
500 - 700 mm
Note (3)
32 NB gal tube
(2.0 wall)
Note (2) & (5)
Kilometre plate
marker
Section 24.2.1
2165 mm
550 - 650 mm
Note (3)
50 NB gal tube
(3.2 wall)
Note (2) & (5)
General use for side
mounted signs, except
where larger or
special post required.
1, 2, or 3 post mounting
2800 mm
3200 mm
3700 mm
4600 mm
600 mm (min)
1000 mm (min)
Note (3)
80 NB gal tube
(3.2 wall)
Note (2) & (5)
Medium-large signs in
protected locations.
2 or 3 post mounting
Length to order
900 to 1200 mm
No
Note (4)
100, 125 and 150 NB gal
tube (3.5 wall) Note (2) and
(5)
Large signs in protected
location (2, 3 or 4 post
mounting). Single post
mounting in urban areas
where V85 ≤ 60 km/h
(Section
6.4.2)
Length to order
1200 to 1400 mm
No
Note (4)
180 x 100 mm frangible
hardwood Fig 6.2
Medium-large signs in
exposed locations,
generally freeways and
rural areas only.
2 or 3 post mounting.
Length to order
1200 mm
Yes
Note (4)
Table 6.1: Standard Sign Post Types and Uses
Notes to Table 6.1:
1.
Depths may need to be increased in soft ground to ensure post stability.
2.
Galvanised steel tube used for sign posts is to be made from C350 grade steel. Tube sizes are specified by nominal bore (NB) and wall
thickness, both in mm. Figure 6.1 assumes tube wall thickness as noted in the above table. However, lighter gauge 50 NB tube, with 2.3 mm
wall thickness, may be used to support signs of area up to 0.8 sq.m per post at sign centroid heights of up to 2.2 m. This tube will thus be
suitable for single post mounting of small signs, and for multiple post mounting of wider but relatively shallow signs such as intersection
direction signs.
3.
Posts of 50 mm nom. bore or less are not breakaway types, but are considered light enough to present minimal hazard to out-of-
control vehicles.
4.
Timber or frangible posts are generally not appropriate for use in urban areas (freeway main carriageways and ramps excepted)
where roadside space is restrictive and pedestrian activity exists. As far as practicable, steel posts up to 100 mm nom. bore should be used in
lieu. In especially vulnerable locations post size is desirably limited to 80 mm.
5.
Galvanised square tube, of equivalent strength to the circular tube sizes shown in the above table, may be used as an alternative type of
sign post.
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Figure 6.1: Sign Post Selection Guide (All dimensions in millimetres otherwise shown)
Notes to Figure 6.1:
1. Dimension H and H1 relate to ground surface below sign. On uneven ground, H = height of the longest post.
2. For 3 post mounting conditions, see Section 6.2.1.
3. See Note (4) to Table 6.1 regarding use of frangible posts in urban areas.
4. Use of Slip Base Strutted Aluminium Posts has been discontinued, see Clause 6.2.2.
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Figure 6.2: 1800 X 100 mm Frangible Hardwood Sign Post (All dimensions in millimetres unless
otherwise shown)
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6.2.3
Determination of Post Length
The length of post required comprises the sum of:
•
the signboard depth less 50 mm (clearance at top of sign),
•
the mounting height, adjusted for difference between pavement level and ground level at base of post,
and
•
depth of post into the ground, Table 6.1.
Where applicable, a standard length should be selected from Table 6.1, which retains the above
dimensions within their permissible ranges. If this is not practicable a special length may need to be
ordered. Timber posts and the larger sizes of steel and aluminium posts are ordered to the exact
desired length.
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6.3
Fitting Selection
Examples of sign post fittings and their uses are shown in Figure 6.4.
Some of the fittings illustrated in Figure 6.4 are proprietary designs. Other fittings that have the same
performance may be substituted for them.
Figure 6.4: Sign Post Fittings
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To select the type and number of fittings required:
•
Determine whether the sign will be stiffened on the back with “Unistrut” channel or similar. In
general, the following permanent sign blanks are stiffened:
o
Rectangular, square and octagonal signs wider than 700 mm,
o
Diamond warning signs 750 x 750 mm and larger,
o
Triangular signs wider than 750 mm,
However, 1800 x 300 mm hazard markers are not stiffened,
•
Determine whether back to back mounting of two signs is required,
•
Taking account of the type and size of post to be used, select an appropriate fitting from
Figure 6.4,
•
Taking into account that for stiffened signs, one fitting is required at each intercept point of
post and horizontal stiffening section, determine the number of fittings required for each
separate sign on the basis of:
o
One fitting per post for signs up to 200 mm in depth,
o
Two fittings per post for signs 201 to 900 mm in depth,
o
Three fittings per post for signs 901 to 1200 mm in depth,
o
One extra fitting per post for each 400 mm increment or part thereof above 1200
mm.
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6.4 Special Procedures
6.4.1
Posts in Sockets
Where a sign is to be erected in paved areas or in a location where it could be expected to be struck
from time to time by vehicles, e.g. on an urban median end; or where it may need to be removed
occasionally to accommodate the swept path of over-dimensional vehicles when turning, the post
should be inserted into a socket cast into the ground. Suitable socket sizes for posts are as follows.
Post Size
Socket Size
32 mm nom. bore pipe (hazard markers)
50 mm nom. bore pipe
50 mm nom. bore pipe
65 mm nom. bore pipe
The socket should be set into the ground to the same depth as the post would otherwise have
been set and should protrude approximately 50 mm above an earth surface, or 25 mm above a
concrete or bitumen surface.
The socket may be blocked off so that the sign post penetrates a minimum of 450 mm into the
socket. The sign post should be securely fixed into the socket by an approved vandal proof method.
6.4.2
Single Post Mounting for Large Signs
The mounting of large signs on two posts in some locations in urban areas, for example, above
a footpath, may present a problem in that the structure may be aesthetically displeasing, or one of
the posts may be an obstruction to pedestrians or otherwise difficult to site.
Designs for standardised single post, side mounted sign structures utilising 114 mm, 140 mm or
165 mm OD galvanised steel posts are provided in Appendix 6A. The designs are suitable for
mounting heights (ground to lower edge of sign) up to about 2.6 m, and subject to certain signboard
shape limitations (width/ depth ratio) the post may be offset by up to 400 mm from the edge of the
sign. Typical maximum signboard sizes which may be mounted this way on a 165 mm post can be
estimated from Figure 6.5 for post offsets of 0 and 1 m.
Such supports will, however, be more costly than conventional two-post mounting, and are not to be
made as breakaway supports.
Figure 6.5: Maximum Sign Board Sizes on Standard Single Post Support
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6.4.3
Joint-use Supports for Side Mounted Signs
Wherever practicable in urban areas, existing roadside poles, lighting columns, traffic signal pedestals,
etc. should be used for the mounting of signs to reduce as much as possible any unsightly proliferation of
poles in the environment.
Small signs, generally not more than 0.3 sq.m in area, may be attached to electricity distribution poles,
tramway poles, lighting columns and signal pedestals or mast arms by banding to steel or concrete
columns.
Larger signs may require that the pole be checked structurally for the added loading of the sign, or may
require the design of special joint-use supports. The latter will normally apply where traffic signal
pedestals are to be used. Large signs will rarely be permitted on electricity distribution poles. In most
cases, larger signs will need specially designed attachments for fitting the sign to the pole. The
assistance of an experienced traffic engineer should be sought in locating signs most advantageously in
such cases, and a structural engineer should be consulted where special structures or attachments, or
checks on existing structures, are required.
Typical maximum signboard areas which may be attached to joint-use structures are as follows:
Standard 114 mm OD signal pedestal
-
1.0 sq.m
Special 165 mm OD signal pedestals
-
2.7 sq.m
(Installed only by special arrangement with VicRoads' Signal Installation & Maintenance Section)
Joint use traffic signal/lighting column or traffic signal mast arm - 1.6 sq.m less the area of any
traffic signal target boards facing in the same direction.
When contemplating the use of joint-use supports for signs it is necessary to ensure that:
•
the function of the sign is not adversely affected by relocating it on a joint-use support,
•
all required lateral and vertical clearances are provided, see Sections 5.2 and 5.3,
•
permission is obtained for use of structures which are not VicRoads property.
See also Section 7.4.8 regarding joint-use structures for overhead signs.
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6.5 Colour of Sign Supports
Sign supports are normally left unpainted, except as follows:
•
Sign supports on declared roads (along with traffic signal pedestals) may be painted where
requested by Councils or developers provided that they agree to meet all associated costs,
including maintenance. This is conditional upon the Council/developer entering into an
agreement to reinstate the poles to their original condition in the event that the
Council/developer discontinues its own colour scheme,
•
In isolated situations (i.e. where painting of sign supports has not been initiated), posts may
need to be painted in order to reduce any undesirable aesthetic effects using an approved
neutral colour (e.g. at channelised intersections),
•
Unless galvanised, large diameter steel posts and all overhead or high mounted sign
structures are either painted an approved neutral colour or finished with a zinc-in-silicate
coating,
•
If it is necessary to use timber posts for large direction or similar signs in urban areas, they
may be painted an approved neutral colour on aesthetic grounds.
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Appendix 6A Design Standards for Single Post Mounting of
Large Signs
6A.1 General
The following charts are used to determine whether a sign can be mounted on a single post utilising 114 mm, 140
mm or 165 mm OD galvanised steel posts.
6A.2 Post Size Selection Procedure
With reference to Figure 6B.1:
1. Determine the area of the sign (A x B) and mounting height "H1".
2. Determine offset "S" and select the appropriate Figure 6B.2, 6B.3, or 6B.4, rounding up to the next whole
number offset.
3. Determine the post size by projecting horizontal and vertical lines knowing mounting height and sign area.
The post size required is the one above the intercept point.
Figure 6B.1: Typical Single Post Mounting Arrangement
6A.3 Channel Size Selection Procedure
Single post mounted signs require larger horizontal sign stiffening sections as these signs are cantilevered.
1. Determine the outreach, which is the horizontal distance from the centre of the post to the furthest edge of the
sign.
2. Knowing the sign depth "B", determine from Figure 6B.5 the number and size of stiffening sections required.
Upon erection of the sign, the 41 mm x 41 mm channel section transport bracing shall be retained, but cut to provide
50 mm clearance inside the top and bottom edges of the sign.
6A.4 Maximum Sign Area and Typical Drawing
Table 6B.1 tabulates the maximum sign areas that can be supported for various post sizes taking into account the
mounting height and offset mounting arrangement.
Figures 6B.6-6B.9 show typical sign manufacturing drawings that include details of horizontal stiffening sections and
transport bracing. Also included are standard drawings for General Arrangement, Sign Mounting Brackets and Post
and Footing details.
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Figure 6A.2 - Post Size Selection
Figure 6A.2 – Post Size Selection
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Figure 6A.3 - Post Size Selection
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Figure 6A.4 - Post Size Selection
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Figure 6A.5 - Channel Size Selection
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Post:
165 CHS
140 CHS
114 CHS
Offset:
0.0
1.0
2.0
0.0
1.0
2.0
0.0
1.0
2.0
Height:
m
m
m
m
m
m
m
m
m
1.5
11.36
10.36
6.94
8.57
7.50
5.03
5.51
4.56
3.06
2.0
9.51
8.86
6.35
7.05
6.37
4.57
4.43
3.85
2.77
2.5
8.09
7.65
5.79
5.92
5.48
4.16
3.66
3.29
2.50
3.0
6.98
6.68
5.28
5.06
4.76
3.78
3.08
2.84
2.26
3.5
6.10
5.88
4.82
4.39
4.17
3.44
2.64
2.47
2.04
4.0
5.38
5.22
4.41
3.84
3.69
3.13
2.28
2.17
1.85
4.5
4.78
4.66
4.04
3.39
3.28
2.85
1.99
1.91
1.67
Table 6A.1 - Maximum Sign Area For Single Post Support Signs (M 2)
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Figure 6A.6 - Typical Sign Face Design Detail For Single Post Mounted Support
FIGURE 6B.6 - TYPICAL SIGN FACE DESIGN DETAIL FOR
SINGLE POST MOUNTED SUPPORT
6-33
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Manual Vol 2, Chapter
6 - Edition 3, December 2001
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Figure 6A.7 - Standard Single Post Sign Support General Arrangement
FIGURE 6B.7 - STANDARD SINGLE POST SIGN SUPPORT
GENERAL ARRANGEMENT
6-34
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Figure 6A.8 - Standard Single Post Sign Support Sign Mounting Brackets
FIGURE 6B.8 - STANDARD SINGLE POST SIGN SUPPORT
SIGN MOUNTING BRACKETS
6-35
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Manual Vol 2, Chapter 6 - Edition 3, December 2001
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Figure 6A.9 - Standard Single Post Sign Support Post and Footings
FIGURE 6B.9 - STANDARD SINGLE POST SIGN SUPPORT
POST AND FOOTINGS
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