Traffic Engineering Manual Volume 2
Chapter 5: Side Mounted Signs: Siting and Location
Traffic Engineering Manual Volume 2, Chapter 5 – Edition 4
July 2014
1
5
Heading 1
Amendment Record
Ed/Rev No
Page(s)
Issue Date
Amendment Description
Ed 1
All
July 1986
Original Manual
Ed 2
All
April 2000
Initial draft for comment (VicRoads only)
Ed 3
All
December 2001
New Edition
Ed 3 Rev 1
11
November 2004
Correction to Section reference
Ed 4
All
July 2014
Minor Amendment
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July 2014
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Contents
5.1
General ............................................................................................................. 4
5.1.1
General Principles ............................................................................................. 4
5.1.2
Sight Distance Obstruction ................................................................................ 4
5.2
Lateral Placement............................................................................................ 5
5.3
Height ............................................................................................................... 6
5.3.1
Height Selection Criteria .................................................................................... 6
5.3.2
Standard Mounting Heights ............................................................................... 6
5.4
Longitudinal Placement .................................................................................. 7
5.4.1
Position Signs.................................................................................................... 7
5.4.2
Advance Signs .................................................................................................. 7
5.4.3
Multiple Messages............................................................................................. 7
5.5
Avoidance of Specular Reflection ................................................................. 8
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5.1
General
5.1.1
General Principles
A sign should be located so that:
•
•
•
•
•
•
it is as near as practicable to the edge of carriageway consistent with safety and possible dirt
accumulation,
it can be seen by the driver in time for the appropriate response to be made, see Volume 2 Chapter 4,
Sections 4.2.1, 4.2.2 and 4.2.3 of this manual regarding sign legibility distance,
it is clear to approaching drivers as to which intersection or part of an intersection the information or
instruction on a sign pertains,
it is in the approaching driver’s field of view for the greatest possible distance, at least for sufficient time
for the sign to be noticed and read,
it is not obscured by natural or man-made features, or by other road furniture. The desirable minimum
distance over which a sign should be seen is the legibility distance of the principal legend size, plus an
additional one third of this distance to allow sufficient time for the driver to see the sign prior to reading
its text, and
it is as prominent as possible having regard to the background against which it is viewed.
Erection of signs shall conform to the requirements of VicRoads Standard Specification Section 714 - Sign
Installation (2011).
5.1.2
Sight Distance Obstruction
When locating signs at intersections, median openings, separator openings and the like, care is necessary
that the signs do not obstruct intersection sight distance to oncoming traffic for drivers about to enter or
cross the major road carriageway. As a minimum (“stop”) condition, a driver of any type of vehicle, when
stopped at a stop line or holding position, should have an unobstructed view of oncoming traffic for at least
the distance along the major road equivalent in travel time to the gap required to complete any appropriate
manoeuvre in safety. This view should be available to the entering driver from a position not less than 3 m
measured back from the stop or holding position. A detailed description of sight distance is contained in
Section 3 of Austroads Guide to Road Design Part 4A: Unsignalised and Signalised Intersections (2010).
Small signs erected parallel to the line of sight will not necessarily obstruct the view.
Where a driver may not necessarily be required to stop before entering the major road, i.e. the “give way”
condition, the driver’s view of oncoming traffic available over the last 10m (urban) or 16 m (rural) measured
back from the holding position shall be assessed to ensure that any sight obstruction due to signs or other
road furniture will not significantly affect the driver’s assessment of oncoming traffic.
Signs may be raised or lowered to improve intersection sight distance provided the needs of all road users,
including trucks, bicycles, motorcycles, and pedestrians, are taken into account.
Provisions for the minimum (“stop”) condition is also desirable at signalised intersections to provide for safe
operation in the event of signal failure.
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5.2
Lateral Placement
The lateral clearance from edge of road to inner edge of signs is illustrated in Figure 5.1. The minimum
clearances illustrated are based on minimising damage caused to signs by vehicles travelling close to, and
perhaps overhanging, the kerb. In many situations larger clearances will be necessary, e.g. where large
vehicles turn at intersections.
On freeways and roads in rural areas, any large sign which does not have breakaway supports (posts
larger than 50 mm nominal bore or equivalent), (see Volume 2 Chapter 6, Section 6.2.2 ‘Post type and
Size’ of this manual), must either be located behind guard fence, or on a cut batter 2 to 1 or steeper with no
exposed part of the support or its foundation less than 1.2 m vertically above the level of the toe of batter.
For large signs on urban roads in exposed or hazardous locations, the requirements set out in Volume 2
Chapter 7, Section 7.3.2 ‘Lateral Clearance and Shielding of Sign Supports’ of this manual regarding lateral
clearance shall apply to non-frangible sign supports.
Figure 5.1: Minimum Clear Distance Between Sign and Edge of Carriageway
Notes to Figure 5.1:
1. On freeways including section of ramps up to 30m beyond exit noses, signs exceeding 2 sq.m in area
with breakaway supports should have at least the clearances shown, but are preferably located approx.
2m clear of the outer edge of shoulder.
2. At traffic islands additional clearance may be required to allow for overhang of turning vehicles.
3. May be reduced to 300 mm where width available for sign placement is restricted, provided pavement
crossfall near kerb, or other factors are such that a high vehicle close to the kerb will not hit the sign.
4. May be reduced to 300 mm in urban areas as long as sign post location is clear of guard fence post.
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5.3
Height
5.3.1
Height Selection Criteria
Selection of the appropriate mounting height for a sign is based on the following factors:
•
On rural roads, it should be low enough to lie within the headlight beam at night, but high enough to
avoid collecting excessive dirt from passing traffic,
In urban areas, it should be high enough to avoid being obscured by other traffic or parked cars, or
being a hazard to pedestrians.
•
5.3.2
Standard Mounting Heights
The minimum permissible vertical heights measured from the lower edge of the sign or group of signs on
the one mounting, to the level of the nearest edge of the road to which the sign applies, are given in Table
5.1. These heights are based on the general principles outlined in Section 5.1.1 of this manual.
(a)
Rural Roads: All signs except as in (e) to (j)
1.5 m
(b)
Urban Roads: Kerbside with no parking
2.0 m
(c)
Urban Roads: Kerbside with parking
2.2 m
(d)
All signs on medians or traffic islands except as in (e), (f) and
(h)
1.5 m
(e)
All intersection direction signs except where sight obstruction
problems dictate special mounting heights
2.0 m
Hazard marker signs (except where used as T-junction sight
boards, see (a), (b) or (c))
0.5 m to 0.7 m
(f)
(or 2.2 m, see (c))
Keep Left signs on local urban roads (mounting heights shall
be increased to 1.5 m in other locations, see Figures 13.1
and 13.2 in Volume 2 Chapter 13 of this manual)
(g)
Signs suspended above footways, i.e. substantially over the
normal pedestrian path - height above foot-way level
2.5 m
(h)
Signs mounted on breakaway posts larger than 50 mm
nominal bore pipe. Height above ground level at base of post
2.2 m
(j)
Freeway signs in excess of 2 sq m in area, except as in (h)
1.5 m
Table 5.1: Minimum Mounting Heights for Side Mounted Signs
Note to Table 5.1:
1. The maximum mounting height for signs should not significantly exceed the heights in Table 5.1 unless
required for visibility, say over a crest, i.e. signs should not be mounted too high just to alleviate the
need to cut the tops off the posts.
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5.4
Longitudinal Placement
5.4.1
Position Signs
If a sign marks the point at which a regulation has effect, or at which a decision must be made, or some
other action is required, its longitudinal position is generally fixed to within a few metres. Standard locations
are specified both in these guidelines and AS 1742:2010 for the placement of various types of signs.
However, special care is often required regarding the size of signs and their lateral placement and height to
achieve adequate legibility and reading distance. Advance warning of some regulatory signs may be
necessary, e.g. see Volume 2 Chapter 9, Section 9.4.4 ‘Advance Warning of Intersection Control Devices’
of this manual.
5.4.2
Advance Signs
If a sign is of a type which gives advance warning of a hazard etc., or advance information of a decision
point, its required minimum distance (D) in advance of that point can be calculated as follows:
D = (Reading Distance + Reaction Distance + Deceleration Distance) minus Legibility Distance
However, for simplicity, the following practice is normally adopted:
•
•
•
For signs which give advance warning of a hazard or of a single specific action required of a driver, i.e.
not involving a decision, the distances given for warning signs in Volume 2 Chapter 9, Section 9.1.6
‘Sign Location’ of this manual are appropriate,
For signs which require a simple decision to be made, e.g. a navigational decision arising from an
advance direction sign, the distances in Volume 2 Chapter 9, Section 9.1.6 ‘Sign Location’ of this
manual may be sufficient in restricted choice situations, say where only one alternative route choice is
available. For each additional choice or element of complexity in the decision, as a guide, the distance
should be increased by the equivalent of about 1 second of travel time,
For signs requiring complex decisions, such as services or tourist facility signs, a distance equivalent to
about 12 seconds of travel time is normally used.
These distances may be reduced appropriately where a larger than normal sign, with increased legibility
distance, is used.
The maximum distance at which any advance sign is located should not generally exceed the equivalent of
about 15 seconds of travel time (i.e. the “short term memory refractory period”), unless it is accompanied
by a second advance sign having the same message not more than about 15 seconds in advance of the
hazard or decision point. In such cases a distance plate (see Volume 2 Chapter 9, Section 9.11.4 of this
manual) is added to the first sign, or a distance is included on the sign, e.g. freeway advance guide signs.
5.4.3
Multiple Messages
Generally, there should not be more than one sign of a particular type on each post, except where one sign
supplements another (e.g. advisory speed signs with curve warning signs), or where route or directional
signs must be grouped. Where it becomes necessary to convey two or more different messages at the one
location, separate signs located a minimum of 0.6 V metres apart (where V is 85th percentile speed in
km/h) should be used. See also Volume 2 Chapter 9, Section 9.1.5 ‘Multiple Messages’ of this manual.
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5.5
Avoidance of Specular Reflection
Specular reflection will occur when a sign is almost exactly at right angles to the line of an approaching
vehicle, so that, at night, a bright mirror image of the vehicle headlamps will be seen in the sign by the
driver, often rendering the sign unreadable for an appreciable period.
To avoid specular reflection, side mounted signs should be rotated away from the road by approximately 5°
as illustrated in Figure 5.2.
Figure 5.2: Method of Avoiding Specular Reflection from a Sign
Notes to Figure 5.2
1. Sign is rotated away from normal approximately one tenth of the width of sign as per examples.
2. On RIGHT HAND curves the sign is placed on the normal to the road at the sign position, except for
very large curves (e.g. R>1500mm) which are treated the same as straights.
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