JENNIFER GUSTAVSON PHOTO | A new study suggests a traffic light should be installed on Route 58 in Riverhead where a Costco and other stores have been proposed.

Another traffic light could be coming to Route 58 in Riverhead.

The final environmental impact study for Shops at Riverhead — where a Costco and other stores have been proposed for a 270,000-square-foot shopping center on the north side of Route 58 — is suggesting that a traffic signal be placed at the entrance to the planned retail complex, town officials said.

The traffic signal would link the entrance to Shops at Riverhead with that of another shopping center proposed for the other side of Route 58, said Riverhead Town planning director Rick Hanley.

That second shopping center, from an applicant named Saber-Riverhead LLC, calls for a 114,700-square-foot retail building on the south part of the property and a 3,900-square-foot retail pad fronting Route 58. The 14-acre site, which was tied up in litigation for seven years under its previous owner, is located just east of Riverhead Raceway.

Since Route 58 is a county road, it would be up to the county Department of Public Works to decide if a traffic light is warranted at this location, Mr. Hanley said.

There are now nine traffic signals along Route 58 between the Roanoke Avenue traffic circle and the end of the Long Island Expressway, five of them between Kroemer Avenue and the large Riverhead Centre shopping center. The county is already planning to change the Kroemer Avenue intersection once a super Walmart is built across from Tanger Outlet Center. That project has already received town approval.

The newest traffic light, which became operational late last year, is at the intersection connecting the new Lowe’s store with the easternmost entrance of Riverhead Centre. Town Board members and county Legislator Ed Romaine (R-Center Moriches) lobbied for that light after the county Department of Public Works initially rejected the idea. Lowe’s threatened to abandon its Riverhead project if the traffic signal wasn’t approved, but Mr. Romaine saw to it that the public works ruling was overturned.

“I would think we’re going to get a light there,” Mr. Hanley said of the proposed Costco light during a discussion during Tuesday’s planning department work session.

“Just because they are showing it on the site plan doesn’t mean DPW is going to give them one,” said Councilwoman Jodi Giglio, who sat in on the session.

tgannon@timesreview.com