Changes on Interstate 395 will soon be evident now that the state has begun installing milepost-based exit signs, a project that's set for completion by the end of 2015.

Motorists from New London County to the Massachusetts line can expect to see the first new exit numbers this winter, according to state Department of Transportation supervising engineer Michael W. LaLone. He said sign support foundations are currently being installed by Danbury-based A.M. Rizzo Electrical Contractors Inc., the winning bidder on two sign replacement projects covering the upper and lower sections of the interstate.

LaLone said the new system is based on mileage. Exit 77 in Waterford, located two miles from the start of the highway in East Lyme, will become exit 2; exit 100 in Thompson will become exit 53 because it is 53 miles from the start.

The change is a response to federal mandates that require exit numbering to match mile markers, according to DOT spokesman Kevin Nursick. The guidelines are contained in the Manual of Uniform Traffic Control Devices, 2009 Edition.

DOT also plans to implement the new system on Route 2A.

Because signage along the entire length of the interstate was at the end of its useful life, Nursick said, the state was forced to comply with federal exit numbering requirements in order to get approval and funding for the large-scale replacement project.

The new signs will carry the former exit numbers for a minimum of two years, Nursick said.

“Including the old exit number signs doesn’t just allow motorists to get acclimated; it also allows businesses time to update their brochures, etc.,” he said.

John Filchak, executive director of the Northeastern Connecticut Council of Governments, said those he’s heard from in the region’s business and tourism community support the new numbering system.

“It may be easier for the visitor to comprehend and therefore be beneficial to the businesses that are dependent on people who will get off the highway,” he said.

He cited approximately 7.7 million cars traveling from the Massachusetts border into Connecticut on Interstate 395 in 2012, according to state traffic logs.

“We don’t grasp a decent percentage of those getting off,” Filchak said. “Tourism is on the minds of a lot of these towns, whether they’re trying to promote a restaurant, the new race track in Thompson or antiques on (Route) 169.”

But he’s also heard from people who question the use of federal funds for the highway project when they believe there are many more pressing needs.

According to Nursick, the change is about consistency and logic not only across the state, but also nationwide. Just as a stop sign means the same thing no matter where you go, he said, consistency in exit numbering contributes to a smoother, safer ride.

The federal Interstate Highway System, also known as the Eisenhower Interstate System, which includes 395, was created by the U.S. government and is managed by the U.S. Department of Transportation and its Federal Highway Administration arm.