Flagstaff, AZ installs AC traffic system
TEMPE, AZ - 05/01/2008 - The city of Flagstaff recently added two additional school flasher systems from Solar Traffic Controls. Despite an abundance of
sun, the city chose AC-powered systems. The city's traffic engineering department also opted to try a new approach using an LED changeable speed limit sign in conjunction with the flashers to control speed in one of their school zones.
During non-school access hours, the system flashers are dark by the LED
speed limit sign showing a posted speed of 35 mph. During school access
hours-morning drop off, midday release and afternoon release-the flashers
are activated and the LED speed limit sign drops to 25 mph. The systems were
tested and commissioned in April.
Since the city already has been equipped with solar-powered school flashers
for several years, STC opted to design the systems with all DC components to
match the existing systems and minimize the learning curve. AC line power is
brought into each pole and run into an AC-to-DC converter unit.
Time-based operation of the units is accomplished using the STC-01 time
clock used by the city in their other systems. Eight-inch amber DC LED lamps
are located at the top and bottom of the sign, and at the rear of the units
to remind drivers of the school zone's reduced speed and to act as
confirmation lamps for police officers monitoring speeding in the zone.
The DC lamps were furnished by STC using a design by Precision Solar
Controls. The changeable speed limit sign is a product of Information
Display Company and is similar to the VSC-1520 radar speed display with one
exception: there is no radar in the unit. The auxiliary dry contact output
from the STC-01 changes the speed limit on the sign whenever the lights are
Solar Traffic Controls (STC) provides solar-powered traffic control systems
to city, state and federal DOTs; police, firefighting, industrial facilities
and public works departments. Primary products are solar-powered flashing
beacon systems used for school zones and 24-hour applications. For more
information, please call 480-449-0222.
Further information about Information Display's changeable speed limit sign: