The state Department of Transportation is warning of travel delays on the northbound side of the Gold Star Memorial Bridge starting at 7 p.m. Thursday as crews replace a loose expansion joint panel and inspect other panels.

DOT spokesman Josh Morgan said three lanes will remain closed through 3 a.m. Friday.

He said a DOT staff member who happened to be driving over the bridge alerted the agency to what appeared to be a loose panel. The expansion joints are placed where the highway meets the bridge to allow for movement caused by temperature changes and other factors.

It’s unclear at this time what caused the four-foot metal or composite panel on the New London end of the bridge to become loose, Morgan said. Repairs involve removing the panel, replacing and securing it.

He said the problem is likely due to “wear and tear.”

The problem does not affect the structural steel or anything supporting the bridge, according to the spokesman.

“It’s still structurally sound,” he said. “It’s still safe for motorists.”

The DOT is currently working on a large-scale project to repair and strengthen the northbound span, which 60,000 vehicles drive across each day. The first phase is focused underneath the bridge, with rehabilitation of the bridge deck – including the expansion joints – expected in the next phase.

Morgan estimated phase two will begin in 2025, immediately following the truss work.

One lane was already closed as part of the rehabilitation project as crews work beneath the bridge to knock out old rivets and replace them with high-strength bolts, Morgan said. The intent is to keep vehicles off the bridge, which has weight restrictions, in the area the work is being done.

According to a 2021 inspection, the northbound side's deck and superstructure were rated as “poor” and its foundation was rated as "fair," but the DOT has said the bridge is safe to drive on.

A different type of repair related to an expansion joint on the Groton end of the northbound span was made on Nov. 10 when traffic was snarled for hours on the bridge and surrounding areas while crews fixed a patch of deteriorated concrete that had resulted in multiple flat tires.

The span was built in 1943 and underwent its last major rehabilitation project in the 1970s, with additional maintenance performed over the years. Morgan said about half of the $316 million project is covered by federal funds.

e.regan@theday.com