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Required elements
45.3.4
Graphical overview
Description
Required elements
45.3.5
Description
762
For 2D, at least a 2D line and a 2D centreline are required.
•
•
For 3D, a 3D line and a 2D or 3D centreline are required.
Measuring Local Lines without Centrelines
Stake road
c
b
d
e
a
Road_085
Stakeout of Roundabout
a
Position to stake out
b
Line to stake out
c
Centreline of the layer- is not
used for the local line
d
Chainage
e
Difference in chainage
f
Difference in offset
g
Difference in height
This process is different to lines, where the stake/check is always relative to
the centreline defined for the layer. Local lines no longer have a relationship to
an overall centreline. Local lines are used to check roundabouts, parking bays,
subdivision works and any other type of lines. The different lines to stake/
check can be stored within one layer, which does not require a defined centre-
line. This ability is different to the stake/check of any other type which always
require a centreline.
A 2D or 3D design of the line to stake/check is required.
Indefinite Triangle
In almost all situations, a measured position is shown relative to the local line
by the line chainage and a square offset to the line. However, situations can
arise where a road design has extreme changes in the deflection angle of tan-
gent points. In these cases, it is not always possible to show a measured posi-
tion by the nominal chainage and offset. An indefinite triangle is a region in
which these situations arise. Points measured within an indefinite triangle are
shown relative to the tangent point.
Check road
f
g
Road_084
Checking a Roundabout
a
Line to check
b
Chainage
c
Centreline of the layer- is not
used for the local line
d
Difference in offset
e
Difference in height
c
a
b
d
e
Roads - Road
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