RALEIGH — The oldest part of Raleigh’s Beltline was constructed in 1960, and is due for an overhaul.

This 3.5-mile stretch of Interstate 440, from Wade Avenue in West Raleigh to Walnut Street in Cary, is a quaint time capsule of cramped freeway design. It’s the only part of the Beltline still in its original package – and still just four lanes wide.

But it won’t be that way for much longer. The state Department of Transportation is working up plans for a $92 million upgrade that will widen I-440 with a third lane in each direction. Interchanges will be redesigned with easier on- and off-ramps.

Construction starts in 2018. Many details have not been worked out yet.

DOT engineers will discuss the project and solicit public comment at a citizens’ informational workshop from 4 to 7 p.m. today at the Method Community Center, 514 Method Road.

The state owns only a narrow-right strip along this part of the Beltline, no wider in some places than 80 to 120 feet. Adding two lanes will require more land on one or both sides of a freeway now lined closely with residential neighborhoods, parks, lakes and N.C. State University property.

Drivers have six lanes on I-440 north of Wade Avenue and on U.S. 1 / 64 south of Walnut Street, so the plan to widen the intervening four-lane Beltline section will get rid of a bottleneck.

Other problems to be tackled include the abrupt on- and off-ramps at several interchanges, which give drivers only a little time to hit the brakes for an exit – or hit the gas to enter the freeway. Drivers entering from one exit must watch carefully for drivers exiting at the next one.

“You’ve got a lot of closely spaced, substandard interchanges – Wade Avenue, Hillsborough Street, Western Boulevard,” said Ed Johnson, director of CAMPO, a regional planning agency. “There’s a lot of things that need fixing, but very little right-of-way to do the fixing in. So that’s going to be a challenge.”

The Western interchange probably will be redesigned to eliminate problems caused when drivers from Western merge into the left lane of southbound I-440. That’s the fast lane, where I-440 drivers usually aren’t expecting company.

“Slower traffic tends to keep right, and traditionally that’s where the driver expects merging traffic,” said Eric Lamb, Raleigh’s transportation planning director.

The Method neighborhood will feel the impact when DOT begins acquiring land for the project in 2016. Monday’s meeting takes place in a community building 200 feet from the freeway.

“It’s a very developed corridor, so we need to minimize impacts as best we can,” said Leza Wright Mundt, a DOT engineer developing the plans. “It’s a tight one.”

Siceloff: 919-829-4527 or blogs.newsobserver.com/crosstown or twitter.com/Road_Worrier/