| This City of Carrollton maintains 104 signals. Each of
these traffic signals was installed in accordance with the Texas Manual of
Uniform Traffic Control Devices (TxMUTCD). The TxMUTCD
states that "Traffic control signals should not be installed unless one or more
of the signal warrants in the MUTCD are met. Information should be obtained by
means of engineering studies and compared with the requirements set forth in
the warrants. the engineering study should indicate the installation of a
traffic signal will improve the overall safety and/or operation of the
intersection. If these requirements are not met, a traffic signal should
neither be put into operation nor continued in operation." If one or more of
the warrants are satisfied a signal is not automatically installed. If
based on an engineering study, the signal would not enhance the overall operations
and safety of the roadway, then a signal is not installed. If you have any
further questions or would like to report a problem, please call us at
972-466-9870. |
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Mounted
metal |
In 1978, the City of Carrollton began changing the
appearance of our traffic signals from a vertical mounted signal head to a
horizontal mount. By doing this we provided more clearance over the roadway and
a more pleasing look to our traffic signals. The first thing we learned by
doing this was, the arm that the signal heads were mounted to would bounce up
and down under windy conditions. The bounce in the arm would occur when there was a wind of 15 mph or
greater on the backside of the signal head. After some
research of possible solutions to this problem, we implemented
the use of wind wings. The wind wing got its name from the research of the bounce problem. We
discovered that any time the wind blew 15 mph or greater on the backside of the
arm, the arm would begin to bounce. By mounting a flat sign blank, (30"X60") at the end of the arm, we
created a wind wing that helped divert the wind evenly around the arm, reducing
the bounce. The wind wing is now a standard used on all signal arms over 25
feet long. |
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LED Lights |
Red LED (Light Emitting Diodes) signals use very little energy, just 10.5
watts. A standard signal lamp uses 135 watts and has to be replaced annually.
Light emitting diodes are semiconductors that emit electromagnetic energy,
coincident with the change of energy state, at a diode junction. Simply put,
LED's are miniature lights that use up to 90% less energy than a comparable
incandescent light. The lamp-life is extended up to 10 years, compared to 1 to
2 years for an incandescent lamp. The use of LED traffic lamps, results in
significant reduction in energy and signal maintenance.
The use of LED technology reduces the overall utility bill by reducing the
energy consumed at each signal. It also helps protect the
environment since there are fewer harmful emissions (that is, less fossil fuel
is required to produce electricity). With an average life of 10 years, bulb replacement and maintenance
costs are greatly eliminated. The City of Carrollton
standards for new or upgraded signals call for the use of Red, Green, and Pedestrian LED's. |
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Black camera-like devices |
This little black canister
is for fire pre-emption of the signal, and is called an Opticom system detector. The Opticom
system uses high energy infrared technology to grant authorized vehicles
momentary right-of-way at signalized intersections. The Opticom system gives an
authorized Fire department vehicle a green indication as it
travels, intersection
by intersection. As the vehicle approaches, sends an encoded, infrared signal that is received, decoded, and
validated to give the requesting vehicle a green light on that
approach and a red light on all other approaches. Opticom has helped to provide a quicker response for fire
equipment to arrive on the scene, a little bit sooner. |
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Overhead Street name signs |
The overhead street name
sign features the City of Carrollton logo and a block number. The sheeting is
white and green and is retroreflective. We use a sheeting called 3M Diamond
grade VIP (Visual Impact Performance). Unlike other reflective sheeting we use,
VIP features an advanced prismatic design. As a result, it provides greater
than normal reflectivity and remains highly visible to drivers in all-ambient
light conditions including nighttime conditions. The prismatic cubes on VIP sheeting are specially shaped to
return the light from a vehicle's headlights back to the motorist's eyes. This
controlled light-return makes the sign brighter and visible longer, giving motorists more
time to respond. In other areas of the city you may have noticed the
fluorescent yellow-green school zone signs and the fluorescent yellow warning
signs. We were among the first cities in the nation to use these
colors for school zone use. |
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White Light (Red Light Confirmation Light)
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White lights are used by the
Police Department to assist in the prevention of red light running. Each pole
has a white light mounted on it and is wired to the red light indication for
that pole. The Police Officers can park downstream or anywhere
where the
white light is visible and detect red light runners without parking at the intersection.
This feature allows our Police Department to enhance safety at our
signalized intersections |
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Decorative Pole Caps & Bases |
Decorative pole caps and
bases are part of the city's corridor design plan. It is hard to make a traffic
signal attractive to the eye. Decorative caps and bases have helped to not only
make traffic signals a little more attractive, but also help to identify our traffic
signals as Carrollton signals, and give Carrollton a unique
aesthetic identity. |
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| Yagi
Antenna |
This Yagi antenna is part of
the communication link between the traffic signal controller and the Advanced
Traffic Management Center. With the use of spread spectrum radios, we can
proudly boast having the first wireless traffic signal system in the world. Our
ATM center is staffed from 7:00 a.m. to 6:00 p.m., Monday through Friday. At
the ATM center we monitor all the traffic signals in Carrollton. We have the
capabilities of uploading or downloading data to any traffic signal. We also
have 8-video cameras located around the city, linked to our ATM center by
microwave antennas. All solar powered school flashers are controlled at the ATM center. The ATM center is
located in the South Service Center at 1420 Hutton, and is
open to public tours by appointment, Monday through Friday 8am-4pm call (972)
466-9870. |
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Pedestrian Signal |
Pedestrian signals are
installed to assist pedestrians in safely cross the street at signalized intersections.
The "Walk" light gets you started crossing the intersection and the flashing "
Don't Walk" gives you time to clear the crossing. The way it works is, the
"Walk" time lets you know when it's safe to begin crossing the
street and the flashing
"Don't' Walk" time allows you to get the rest of the way across the intersection.
If the flashing "Don't Walk" signal is flashing before you step off the curb,
you should wait for the next "Walk" signal before crossing. |
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Pedestrian Push
Buttons |
Pedestrian push
buttons are used to activate the pedestrian signals. You only have to push the
button one time to receive a Walk light. It will not make any difference if you
hold the button in or push it many times. All of our pedestrian push buttons are in compliance
with ADA (Americans Disability Act) standards. |
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Video Camera |
Carrollton has 8 video cameras
located at busy intersections linked to the ATM center via
microwave antennas. At the ATM center a system operator monitors the real time
video pictures. The system operator uses this information to assist in incident
management. It is very important when calling in traffic signal problems to
identify the location, the type of problem, the direction of the problem, and
the time of day the problem is occurring. |
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School Flashers |
Solar powered radio
controlled school flashers have been the standard in the City of Carrollton since
1990. The first solar flashers were installed on Peters Colony on August
1,1990. Our city staff designed and installed the first 12" double beacon solar
powered school flashers in the nation and set a national standard for solar
school flashers. From the ATM center we can turn on or off any or all the
school flasher at any time of the day. |
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Control Room |
The Advanced Traffic
Management Center is located in the South Service Center at 1420 Hutton Dr. It
is staffed from 7:00 am to 6:00 pm Monday - Friday and is open for public tours by
appointment Monday - Friday 8:00 am to 4:00 pm |