What is all that stuff anway?
An explanation on the extra stuff on the traffic signal light bars
Most drivers and pedestrians just see the lights – red, amber, green, but what are all those other items fixes on top of and hanging underneath traffic signal control arms throughout the City of Minot?
The signs, such as “left turn YIELD on green,” are easily understood but there’s also several electronic-type devices affixed to several traffic control signals in the city. Is it big brother watching or something else?
One of the smallest items fixed above traffic control arms can be vital to Minot Fire Department trucks responding to a call when a slight delay could mean the difference between life and death. It is a receiver that communicates with firetrucks to provide Emergency Vehicle Preemption, or EVP.
“The system is manufactured by Opticom,” said Dean Lennertz, Minot Fire Department. “It’s at some intersections, not all of them. We have a strobe light on the firetrucks that it picks up and, in turn, transmits to the traffic lights.”
A light mounted on the Opticom receiver activates to let the driver of the firetruck know that the strobe light signal was received. All lights at the intersection, no matter what the direction, turn red. That allows a firetruck to safely gain a temporary right of way and proceed through the intersection to its destination. EVP’s are located along Broadway, Burdick Expressway and a few other key locations in the city.
The largest extra mounted on several traffic signal arms in Minot has the appearance of a platform bird feeder. It’s not, of course, but rather a stabilizer designed to keep the traffic signal arm from moving up and down in response to wind. Underneath the bar is a pair of weights that also serve to minimize motion of the overhanging signal arm.
Minimal motion is necessary for the proper utilization of traffic control cameras, some of which are mounted on traffic signal arms. The cameras are used solely to detect traffic flow. The signal lights operate in conjunction with the cameras in order to give the green light to a line of traffic when there is no traffic attempting to enter the intersection from a crossing street.
Not all traffic lights are controlled by cameras however. Some are directed by loop detectors located underground. When a vehicle enters the magnetic field it causes a disruption that triggers detection equipment in a traffic signal cabinet located near the intersection.
There are currently 44 traffic signals in the city, 34 of which are controlled by a computerized system. The Traffic Engineering Division of Minot’s Engineering Department is responsible for the operation and maintenance of all traffic signals, signs, pavement markings and street lights.