CONCORD, N.H. (AP) – Highway planners got to work Friday to compile new estimates of how expanding Interstate 93 would affect the region, after a federal judge ruled their initial planning did not go far enough.

The additional study, with public hearings and comment period, could add as much as a year to the project planning, further pushing up its costs and jeopardizing work on bridges that need maintenance, Transportation Department spokesman Bill Boynton said.

“We are taking the judge’s decision and trying to make every effort to comply with it as quickly as possible,” Boynton said.

On Thursday, U.S. District Judge Paul Barbadoro ruled that state and federal highway officials must consider the impact of population growth that would be prompted by widening Interstate 93 in southern New Hampshire as part of their planning.

In an 86-page ruling, he ordered the state and Federal Highway Administration to complete a Supplemental Environmental Impact Statement that specifically considers the growth and whether the widening actually would relieve congestion on the highway. The new study also must consider the effects the additional residents would have on secondary roads and air quality.

Boynton said state officials met with their federal counterparts Friday morning to map out a plan.

“It’s still tough to put a time period on it,” Boynton said of the potential 8- to 12-month delay. “Any project in the 2008 (construction) season probably will not be able to go forward,” he said.

That work includes about $75 million in contracts, including bridge work that is about to be put out to bid.

Work already has begun at Park and Ride lots at Exits 5 and 2, he said, and will continue.

Boynton said planners are concerned the delay will jeopardize safety improvements to 10 deficient bridges along the project corridor.

Work would continue on eight bridges around Exit 1 in Salem, which are not part of the widening project.

He said the new review will include public hearings and at least a 45-day public comment period.

The ruling was a significant victory for environmentalists who argue that widening the road to four lanes between Manchester and the Massachusetts border would itself cause population growth that will affect the usefulness of the widening, congest secondary roads and cause air pollution.

The Conservation Law Foundation argued that a study that was not considered by officials in their initial planning, and never presented for public comment, estimates that the widening would be responsible for drawing 35,000 new residents, above any unrelated population growth, to towns along the highway by 2020.

The 20-mile, $700 million, project runs between Salem on the Massachusetts line and the junction of I-93, I-293 and Route 101 in Manchester.

AP-ES-08-31-07 1603EDT