User's Manual

10
Likewise, if the detection coverage is aligned so that the sensor has a view
several feet beyond the stop bar (downstream from the stop bar into the
intersection) it is more likely to have better performance of detecting queue
dissipation. With the installation software, the presence and location of the
stop bar in each lane can be configured in order to enable advanced logic to
minimize the effects of occlusion of small vehicles by queued traffic.
 Closest roadside – It is recommended that you mount the sensor on the side
of the road closest to the lanes of primary interest. In many cases this will
be near side. However, if left turn detection is more critical than through
movement detection the closest road side may be the far side of the
approach. Always mount the sensor high enough to prevent traffic from
occluding approaching detections. If you mount the sensor on the back side
of a mast arm, mount the sensor near the end of the arm to reduce the
potential the mast arm or departing traffic to occlude approaching vehicles.
 Mounting height - Mounting the sensor higher will generally improve line-of-
sight and decrease occlusion of vehicles. A minimum height of 15 feet is
recommended. If the sensor is mounted on a vertical pole with a mast arm,
it is recommended that the sensor be mounted to avoid occlusion of the
roadway by the mast arm. This may require mounting the sensor below the
mast arm.
 Mounting offset – A minimum offset of 6 feet to the first lane of interest is
required.
 Redundant detection – It is possible to have multiple sensors monitoring the
same approach.
 Sensor proximity – When multiple sensors are mounted at the same
intersection, interference can be avoided by configuring each sensor to
operate on a unique RF channel. In cases, where zones are spread over
more than 100 feet, multiple sensors are needed.
 Departing lanes – There is usually no need to view traffic in departing lanes
or to configure departing lanes. However, if they are configured then the
stop bar should NOT be configured.
 Suspended electrical cables - The sensor is designed to work in the
presence of suspended power lines and other electrical cables, however
these cables should be mounted at least ten feet away from the front of the
sensor.
 Neighboring structures and parallel walls – For best performance, it is
preferred that the sensor be mounted without signs or other flat surfaces
mounted directly behind it. This will help reduce multiple reflection paths
from a single vehicle.
 Cable length – Ensure that you have sufficient homerun and sensor cabling.
Cable runs as long as 500 feet are achievable using 24 VDC operation and
the system’s native RS-485 communications. If you have an application
that requires a cable length longer than 500 feet, contact Wavetronix
technical services for assistance.