Work will begin Tuesday to install a cable barrier in the median of Interstate 85 north of Ga. 20.

The road improvement is designed to help prevent crossover accidents in which a vehicle traveling in one direction crosses the median and strikes a vehicle traveling in the opposite direction. Such an accident occurred almost one year ago when 17-year-old Thomas Edward Brown of Hoschton was killed near the Hamilton Mill exit on I-85.

According to police, his 1999 Dodge Dakota was traveling southbound when it left the road, crossed an unprotected, grassy median and collided with a northbound tractor-trailer truck. Brown had been en route to the Lawrenceville Methodist Campground to take part in a community service project in which teens repair homes for the needy. He died at the scene.

Cable barriers have stopped similar accidents farther north on I-85, as well as on other interstates.

A contractor for the Georgia Department of Transportation will install the cable barrier system and — in some areas — a standard guard rail as well. A barrier will be erected from Ga. 20 in Gwinnett County, north through Barrow, Jackson and Banks counties to the Franklin County line, according to the DOT. The project is expected to be completed April 30 and will cost more than $6.5 million.

During construction, no traffic lanes will be shut down, but shoulders will be closed. This week, the shoulder closures will be just north of Ga. 20 on the northbound and southbound inside shoulders.