COEUR d’ALENE — It’s maddening for a driver to approach a green light at an intersection, with no other traffic in sight, and the signal light, for no apparent reason, changes to yellow, then red.

That should be happening less in Coeur d’Alene, and traffic flow should improve on one of Coeur d’Alene's main roads.

The city spent about $40,000 on video detection systems for the Seventh and 11th street intersections on Sherman Avenue.

Todd Feusier, director of the Streets and Engineering Department, said the overhead “present detection” system alerts on vehicles and the traffic lights will change accordingly.

The asphalt sensors at both intersections have not been operating properly for years, and the signal lights have changed per a time-based program, not when there are cars.

“It’s been on our maintenance list,” Feusier said Thursday.

City crews were installing the new detector at 15th and Sherman on Thursday and are scheduled to install one at 11th Street soon. Both must be programmed and are expected to work by mid-August.

“They make the signal lights operate more efficiently,” which will improve traffic flow, Feusier said.

He said it only detects and counts vehicles. It doesn’t record them or take pictures of license plates, as some fear that could be the case.

Feusier said it’s less expensive for the city to switch to above-ground detection systems rather than tear up roads to install new sensors.

He said the city has long been using video detection systems, and has them at about 70% of its traffic lights.

The city plans to replace the remaining asphalt sensors as they fail.

"It's a maintenance thing at this point,” Feusier said.