Traffic signals across the metro area are sporting a new hue.

Tiny blue lights are being added to semaphores to help police catch motorists who run red lights. When a traffic signal turns red, a blue light facing the opposite direction comes on. That allows an officer sitting downstream of the intersection to see that a driver ran the light.

Burnsville was one of the first metro-area cities to use the technology. It has since spread to other cities, including Crystal, Maplewood and Blaine. This fall, Ramsey County installed 120 of the blue lights at 49 intersections along thoroughfares identified as having a significant amount of red light running, said county transportation planner Joe Lux.

"Running red lights has become an epidemic in the last several years," he said. "If you sit at an intersection, it's rare that you don't see somebody sneaking through."

The impetus for installing the blue lights came after a Minnesota Department of Transportation report revealed that Ramsey County had a significant number of right-angled crashes attributed to red light running. With $133,000 in federal grant money plus about $13,000 of county money, the lights were installed at the same time the county installed countdown timers for pedestrians and made other upgrades to intersections to comply with the Americans with Disabilities Act, said county traffic engineer Erin Laberee.

On a mission to reduce crashes

County officials consulted with local police departments and the Sheriff's Office to identify roadways with chronic red light running and decide where to put the blue lights, she said.

Blue lights have been installed along Silver Lake Road from 37th Avenue NE. to Rice Creek Road, on Lexington Avenue from Larpenteur Avenue to County Road E, County Road 96 from Hamline Avenue to Hwy. 61, and on Larpenteur Avenue between Hamline and Century Avenues. Blue lights also went in at the intersection of Cleveland and Roselawn Avenues and at some intersections along White Bear Avenue. Signs alerting motorists that they are entering a red-light enforcement area will be posted, Laberee said.

"We want to raise the awareness and get people to stop running red lights," she said.

Ramsey County Deputy Sheriff Tim Entner said police don't want to be writing tickets, but the blue lights will make it easier and safer for them to spot offenders. In the past, an officer would have to be stationed at the intersection and see that the light had turned red before stopping a driver who had gone through it. The pursuing officer had to follow the vehicle through the intersection, too. Now they can park in a safe place within sight of the intersection and catch the offender as they pass by.

"You don't want to put yourself in a situation where you could get in a crash yourself," Entner said.

It's too early to tell if the blue lights will be a deterrent, but if what happened in Florida is any indication, the number of right-angled crashes should fall. When similar lights were installed there, crashes caused by people running red lights fell by 33 percent, a MnDOT study found. They are getting people's attention.

"If people know they are out there, it will make them think before going through a red light," said Sgt. Matt Smith of the Burnsville Police Department.