For years, U.S. 61 North at Oak Ridge Road was a test of concentration and nerves for motorists, particularly at night.

Traffic signals governing westbound traffic from Oak Ridge were hung above 61 and set back from the feeder road, a situation authorities said made the junction a hotspot for car wrecks — some of them fatal. A yield-when-green sign instead of a protective green arrow governed turning onto Oak Ridge from either side of 61.

All that changed this week when

the Mississippi Department of Transportation unwrapped the final piece of a new system of traffic lights at the intersection.

A new turn lane onto Oak Ridge from northbound 61 has allowed motorists to slow down sooner before turning. Previously, motorists had to slow down to turn in front of traffic that regularly includes 18-wheelers, log trucks and other heavy vehicles that often exceed the posted 55 mph speed limit.

“We’ve added about 200 feet of additional lane there,” MDOT Central District engineer Kevin Magee said of work earlier this year to help move traffic about to turn right onto Oak Ridge at a safer pace.

Put into place Monday is a flashing yellow arrow fixed onto metal arm-style support poles positioned where drivers expect them. The yellow arrow allows drivers to turn left from southbound 61 after yielding, even when the light is red for traffic up and down the main drag. A common sight in larger cities, the additional feature is making its debut in Mississippi this year as MDOT seeks to modernize “problem intersections.”

“They’re plentiful in the Jackson area,” Magee said.

First seen in California and Oregon, the flashing yellow arrow became part of the U.S. Manual on Uniform Traffic Control Devices in 2009. The document is used by the Federal Highway Administration as a standards guide for signs, road markings, and signals.

Flashing yellow arrows reduced crashes at 16 of 17 intersections with previously unprotected turn lanes monitored in a 2007 study by the University of Wisconsin for federal highway agencies. The experiment was done in 15 states, mostly in densely populated suburbs of Portland, Ore., Charlotte, N.C., Miami, Washington, D.C., and other large cities. Conversely, the crash rates either increased or stayed the same at 16 of 18 intersections that went from full green-arrow control to flashing yellow arrows.

Vicksburg Warren E-911 records showed 40 accidents with injuries reported at 61 and Oak Ridge since August 2005. The total covers reports through September 2014, interim E-911 director Chuck Tate said, adding the addition of a new signal system at the junction is overdue.

“It’s about time,” said Tate, a volunteer firefighter in the Culkin fire district who’s responded to several wrecks on 61 outside city limits as part of the district’s response function. “It’s never had a protected turn there.”

Average daily traffic at 61 and Oak Ridge reached 6,800 in 2013, according to MDOT estimates.

Mississippi Highway Safety Patrol investigates wrecks on 61 north and south of Interstate 20 outside Vicksburg city limits. Sheriff’s deputies often arrive first to direct traffic.

Sheriff Martin Pace said he approached Magee more than a year ago to discuss ways to reconfigure the intersection for added safety. Pace hopes the added lane and flashing arrow will be an improvement, but conceded the human element will tell the tale.

“With any traffic light system, it’s only as good as the driver’s willingness to obey the traffic signal,” Pace said.