The Federal Highway Administration has given the green light to improvements at the Interstate 95/Route 3 interchange in Burlington that local legislators say will bring significant traffic relief to motorists who have endured bottlenecks there.

The estimated $800,000 in short-term measures call for building dedicated lanes to separate traffic entering and exiting Interstate 95/Route 128 north at exit 32 from the traffic getting on and off the Middlesex Turnpike in Burlington. The ramp also leads to a heavy retail area that includes the Burlington Mall.

The enhancements were added to a $20.4 million federally funded Interstate 95 upgrade planned by the state in the area of the busy interchange.

The traffic separation will involve the addition of signs, lane striping, and lane barriers, according to state Representative Ken Gordon, a Bedford Democrat, and state Senator Ken Donnelly, an Arlington Democrat, who jointly announced the federal decision.

The specific features of the work are being finalized by state and federal officials, but the improvements are expected to begin by the end of this year, Gordon said.

State transportation officials, responding to a request from the Federal Highway Administration to identify bottleneck locations in the region that could be eased with short-term improvements, last year included the I-95/Route 3 intersection on the list, Gordon said.

After a forum hosted last December by the two legislators, they wrote state Secretary of Transportation Stephanie Pollack in February urging the improvements be added to the larger highway project.

“The engineers from MassDOT listened to our concerns,’’ Gordon said. “One of our most challenging and dangerous bottlenecks occurs at that exit. The separation of traffic heading toward Lowell on Route 3 from the traffic bound for Burlington will address this pressure point.’’

Easing the backups at the intersection also will ease congestion on local roads in Burlington, Bedford, and Lexington, Gordon said.

“These days, most of us use the GPS in our phones or car radios to identify pockets of traffic and get around them,’’ he said. “This means that a driver coming south on Route 3, or east on Route 2, can see the traffic on I-95 ahead and leave the highway in Bedford or Burlington, jamming up town roads that were not built for the number of cars traveling on them.’’

“The real issue here is that we have to reduce the number of cars on the road,’’ Donnelly said. “We’ll be taking a good look at ways we can improve access to public transportation and find creative solutions to our transportation challenges.’’

John Laidler can be reached at laidler@globe.com.