Cameras replace traffic loops
June 28, 2007
CNJ staff photo: Andy DeLisle
What it is: A computerized control system that uses sensor cameras to control traffic at intersections.
How it works: The light stays green on the main throughway until vehicles approach from side streets. When vehicles from the side streets approach, the light turns green for them and remains green for about 7 seconds. If more time is needed, the system is programmed to allow for it.
What was the system before: Before the camera sensors were installed, the city had a loop system underneath the pavement that could sense metallic objects and convey that to the signals. Over several years, the pavement can shift and cause the system to malfunction. There are still loop systems in the city in use.
Drawbacks: The cameras can malfunction in bad weather or in direct sunlight. Only two cameras have had to be replaced since they were installed, one because a vehicle hit a pole and caused the camera to snap and the other because of lightning damage.
Cost: In the last eight years, approximately $455,000 has been spent on the new traffic control system, including $250,000 from the city and the rest from state and federal funding. Each intersection costs about $30,000 for all four directions plus a $15,000 control cabinet that can house the system. Individual cameras cost about $2,500 to replace.
Where they are located: Out of 34 intersections in the city with traffic signals, nine have camera sensors:
21st and Martin Luther King Jr.
21st and Norris
14th and Norris
Prince and 14th
Prince and 10th
Prince and Manana
Prince and Llano Estacado
Prince and Cotton Patch
Grand and Hull
Other: During rush-hour times (7-9 a.m., 11 a.m. to 1 p.m. and 4-6 p.m.) the lights are on a timed system.
Outlook: “If the city has enough money, or an opportunity to get money, we will need to upgrade all the signal systems in the city,” said Harry Wang, Clovis public works director. “It’s an upgrading process as the money’s available.”
— Compiled by CNJ staff writer Tony Gutierrez