Sub-system 4: Road geometrics measuring
RADIS uses an android smartphone based GPS
module to determine the radius of every 100m
road section (see Plate 3). A GPS application
running inside the android smartphone is
configured to stream both the GPS coordinates
and bearings (calculated based on the movement
of the GPS module) to the RADIS data logger via
an opened TCP socket. Three readings of radius
are estimated using: the bearings at the beginning
of a section and at 50m; the bearings at 50m and
at the end of the section; as well as the bearings
at the beginning and at the end of a section.
According to the definition of arc, the formula to
determine the curvature road radius is as shown
by Equation 4.0 [9].
From arc definition,
Plate 2: Lane width measurement using RADIS
software
[4.0]
Where R = radius of curvature
L = Length of curve
D = degree of curvature
(change in bearing)
An inclinometer (RIEREK INC, model: RDD20-
30-09) is securely mounted in middle of the
road survey vehicle to obtain the X and Y axis
orientation of the vehicle. Using the acquired
orientation representing the axis perpendicular to
the axle of the vehicle, the road gradient is directly
obtained. The acquired orientation (in degree) is
multiplied with 1.745 to convert into percentage (1
degree is equivalent to 0.017 radian).
Advantages of RADIS
The RADIS data collection system of road
attributes is accurate, fast, mobile and portable.
RADIS also has the ability to capture high definition
images that are geo-tagged as reference points.
Technological advancement in data acquisition
is rendered incompetent if it requires complex
installation and start up, thus RADIS easy-to-
install and calibrate mobile (camera weight:
2kg/camera) hardware system gives the user
Plate 3: Three readings of radius are displayed
for every image
an advantage in conducting surveys in different
localities without the need of specific survey
vehicles. The calibration process is guided by a
simple step-by-step procedure that can be carried
out by survey personnel. The use of sensors during
the road survey allows for an objective analysis of
the radius and gradient. These measurements
feed into the auto-fill function available during the
coding process (i.e. identification of road features),
which further eliminates coding errors arising from
a subjective analysis of coders with respect to the
road environmental features such as curvature.
The development of a drive through data
recording system is not a new or a breakthrough
technology, especially in developed countries.
However, the experience provided by these
countries allows for in-house development
of a similar system suited to specific country
conditions and requirements. The commanding
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