State highway officials will hold a hearing in town this week to provide residents with details about its plans for replacing the Route 2 bridges over Interstate 95. The project is in an early design phase, and construction is expected to begin next year, according to Michael Verseckes, a state Department of Transportation spokesman. The work will be conducted in stages to limit traffic congestion in the busy corridor, according to a meeting notice posted on the town’s website, www.lexingtonma.gov. The hearing is slated for 7 p.m. Tuesday in the Cary Memorial Building’s Battin Hall, at 1605 Massachusetts Avenue. Two bridges carry Route 2 over I-95/Route 128, and Verseckes said they have both been deemed structurally deficient and will be replaced. The cost of the project is estimated at $33.7 million.