Groton — Emergency work to repair a bridge joint on the Interstate 95 south overpass over Route 184 caused delays and backed up traffic for miles on Sunday.

Kevin Nursick, Department of Transportation spokesman, said the $9 million milling project from the Gold Star Memorial Bridge to Exit 88 has been taking place for the past several weeks. The normal work hours for this project are from 10 p.m. to 7 a.m. but Sunday’s delays were not planned, he said.

The project involves doing preparatory work to the bridge joints. During the prep work to the bridge joints, he said, one of the joints became a problem, requiring the emergency work on the part of the contractors to contain the issue, he said.

“Due to the time requirements to remove material around the joint and to prep the joint as well as the time frames associated with curing concrete, two of three lanes were required to be closed,” said Nursick. “We did open the shoulder, however, to get two lanes of through traffic moving through the work area.”

The traffic delays prompted state police to issue a travel advisory, urging motorists to avoid the area and seek alternative routes. Traffic was backed up as far as Exit 90 in Mystic on Sunday afternoon.