City eyes new traffic light system
For the 37 street lights that are in the city of Marietta, an upgrade is coming for a few and the rest could soon follow.
City officials are hoping to obtain funding for a new system that would keep lights green in times of heavy traffic and recognize what type of vehicle is approaching the intersection.
Almost all of the lights are currently on the loop sensor system, which is buried in the ground. A timer is activated three times during the day to keep the lights green a little longer and account for times of heavy traffic. Lights are also able to run on free mode from time to time where they run only on the timer.
The exception within the city is the light on the hill leading to Marietta Middle School. It has a camera sensor to determine if a vehicle is there because the property is private, not city property.
The old sensor system may be making way for a newer, fresher one first at the intersections of Pike and Acme, and Pike, Seventh and Greene, and later on other roadways.
City Engineer Joe Tucker said the current system for making light changes is outdated and comparable to old TVs where one must manually click through the channels to get to the right one. He added that the new system is very technologically advanced.
“It looks not only immediately at the intersection, but also 600 feet away from the intersection,” he said. “If there is a large group of traffic (approaching the light) it’s smart; it knows what speed you’re going and so forth. In that area before the light, (when it changes to yellow) you have to decide at that point, should I hit the brakes or coast on through. We call that the dilemma zone…(This new light) can extend green time.”
The system can also discern whether the vehicle coming is a car, which can stop more quickly, or a large truck that may need more time.
Tucker said there are a few problems with current lights not turning green when drivers think they should.
“(The sensor might) wait until there are two or three vehicles there (to change),” he said. “Some people might think if they pull up and it doesn’t change it might be broken. Another challenge is (the sensors) sometimes have trouble picking up bicycles or a motorcycle.”
Dale Pierce, utility maintenance foreman for the city of Marietta, is one of the men who regularly does maintenance on the lights and makes sure they are working properly. Input is taken from him by Tucker to determine what upgrade will be made to lights.
He said there’s almost a guarantee the lights aren’t working correctly when there is road construction because each light’s sensors are buried in the ground and can often be damaged by road work.
“When they do construction, they cut the sensors, so (the lights) don’t operate as well,” said Pierce. “A magnetic field is all it is. When you cut it, the magnetic field operates no more.
Tucker said the cost of fixing cut sensors is about $2,000.
Pierce said when construction is done, the sensors are fixed, but until that time, traffic patterns can be chaotic and frustrating for drivers.
“Until they get the road back together, they can’t really (fix them),” he said.
Pierce said there are three zones the city covers, around Putnam Street, Pike Street and Greene Street. Lights on Muskingum Drive and Davis Avenue are not maintained by the city.
The lights are currently set up to automatically adjust the amount of time a light stays green during specific times of day.
“There are three different traffic patterns,” said Pierce. “They determine more or less time (the light stays green) overall. Most of the time it goes on time of day (like rush hour).”
Pierce said the new system is going to make driving much smoother.
“(It will) just go on the amount of vehicles going through the intersection,” he said. “It knows when cars are coming at it, and (sees) cars farther back…It’ll automatically make the switch.”
Tucker added that the new system is going to be great for drivers on the road, especially semi truck drivers, which can be recognized with the new technology.
“It’s very intelligent technology,” he said. “It’s been proven to reduce rear end collisions. It has definite safety benefits.”
The new technology costs about $30,000 per intersection.
Pierce said that though the systems are going to cost “hundreds of thousands of dollars” to install in the future, the city is working on a possible grant to get some funding.
Tucker said the city is attempting to go through the Washington, Wood, Wirt (WWW) Interstate Planning Commission to get funding for an initial traffic safety study through the Congestion Mitigation Air Quality fund. The study has to be done before funds can be obtained for actually putting the signals up. It costs nearly $30,000 and the city would most likely have to pay less than $10,000 because the grant will pay 80 percent.
“(The new lights could come) relatively soon, or it could be the next couple years,” he said.