seconds for raising or lowering. Override stops shall be provided to limit
the gate arm travel in vertical or horizontal position and shall operate
through 90 degrees. The assembly shall be capable of a minimum of 500 duty
cycles per hour. A motor of at least 1/3 HP shall be used to power the
system. The traffic arm assembly shall consist of a hollow aluminum
assembly, wood, steel or fiberglass material with a length of
2.74 m
9 feet
.
Provide a spare arm for each traffic arm assembly. The traffic arm shall
be covered with retroreflective red and white sheeting. See
MUTCD
for
proper orientation of sheeting. Each traffic arm shall be equipped with an
obstruction detector that will automatically reverse the traffic arm motor
when an obstruction is detected.
2.14.2 Presence Detection Safety System Only
The traffic arm shall have a minimum of three red warning lights a minimum
of
100 mm
4 inch
in diameter evenly spaced on the arm. Provide interlocks
and appurtenances to [illuminate][flash] the lights when the arm is
deployed.
2.15 TRAFFIC SIGNALS
Provide traffic signals with light emitting diode (LED) signal modules as
shown on the drawings. The term "LED signal module" in this text shall
refer to an array of LEDs and lens that are capable of providing a circular
signal indication as specified herein and shown on the drawings. All LED
signal modules shall conform to the Equipment Standards of the Institute of
Transportation Engineers (ITE), chapter 2a. The arrangement and size of
signal indications for each LED signal module shall be as shown on the
drawings and shall be in conformance with
MUTCD
.
2.16 WARNING BEACONS
The warning beacon shall include two alternately flashing signal sections.
Each signal section shall have a standard traffic signal face with a
flashing CIRCULAR YELLOW signal indication. Signal sections shall be
mounted horizontally on the warning beacon. The visible diameter of each
signal section shall not be less than
200 mm
8 inch
. When illuminated, the
beacon shall be clearly visible, to all drivers it faces, for a distance of
at least
1.6 km
1 mile
under normal atmospheric conditions unless otherwise
physically obstructed. The yellow lens colors shall be in accordance with
the requirements of
MUTCD
. All flashing contacts shall be equipped with
filters for suppression of radio interference. Beacons shall be flashed at
a rate of not less than 50 nor more than 60 times per minute. The
illuminated period of each flash shall be 1/2 of the total cycle for each
signal section. Operation should be programmable and permit continuous
non-flashing operation through a supervisory signal from the Traffic
Controller Unit (TCU). Provide day-light sensor and an automatic dimming
system to reduce the brilliance of the beacon.
2.17 TRAFFIC SIGNAL SUPPORTS
The design and installation of all traffic control supports shall be in
accordance with
AASHTO LTS-5
and applicable local and state standard
specifications. Traffic signal supports consist of tubular members, mast
arms, pole shaft, base plates, anchor bolts assemblies, foundations as well
as associated connections and appurtenances. Loading evaluations shall be
consistent with local and state guidelines. Ice and wind loads shall be
determined based on the geographic location of the installation in
accordance with AASHTO guidelines. Group loading analysis shall be
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