Wavetronix SmartSensor Advance Extended Range (SS-200E) - User Guide - Manual (Page 8)

INTRODUCTION • SMARTSENSOR ADVANCE USER GUIDE 7
Note
For queue management the SmartSensor Advance Extended Range is recommended
because it allows you to see a greater range and also provides a view of the stop
bar. The SmartSensor Advance Extended Range is also recommended for wrong-way
detection applications. Contact Wavetronix Technical Services for more information.
If your application is dilemma zone protection and/or truck signal priority, SafeArrival™
technology is recommended because it provides significant safety and efficiency advan-
tages when compared with traditional point-based protection. Configuring SafeArrival
technology for dilemma zone protection is as simple as selecting the arrival times, ranges
and speeds that are unsafe and warrant protection. Configuration SafeArrival technology
for truck signal priority requires the additional configuration of the truck discovery range
threshold available with SmartSensor Advance Extended Range.
For green extension, arrival times between 2.5 and 5.5 seconds, ranges from 100 to 500 ft.
(30.5 to 152.4 m) and speeds above 35 mph (56 kph) are generally considered unsafe for
passenger vehicles. For truck signal priority, arrival times between 2.5 and 7.5 seconds,
ranges from 100 to 900 ft. (30.5 to 274.3 m) and speeds above 35 mph (56 kph) are generally
considered unsafe for trucks, buses and other large vehicles.
However, engineering judgment needs to be used in selecting these parameters. For ex-
ample, 2.5 to 5.5 second arrival times are nominal values based upon general 10% and 90%
stopping probabilities. Your agency may suggest protection of slightly different arrival times
for a particular type of high-speed approach.
It may be helpful to consult your agency’s guidelines to verify which traffic conditions war-
rant protection at your intersections. Location of point-detection zones, passage time and
design speed can often be used to discover the arrival times and ranges that warrant protec-
tion. In addition, the minimum speed that would warrant installation of a dilemma zone
protection system may be used as a guideline for the lowest speed to be protected.
If you elect not to use SafeArrival technology, you can also configure SmartSensor Advance
to match your agency’s loop-based dilemma zone protection guidelines. Before doing so, it
is recommended that you explore the benefits provided by SafeArrival technology in detail.
Selecting a Mounting Location
Consider the following guidelines when selecting a mounting location:
˽ Detection coverage – Position the sensor so that it will be able to reach all the speci-
fied advanced detection zones. Also consider that the sensor will track vehicles as they
enter and exit desired detection zones. Accordingly, the sensor will often work better if