Major construction projects along several stretches of Route 128 and Interstate 95 will be shut down during the heart of the July 4 holiday season, but motorists should still expect traffic to be slow going this week.

State transportation officials said that with all work on state highways suspended from noon Tuesday until Thursday morning, any delays caused by the projects then should be minimal.

But AAA Southern New England was projecting heavy traffic in New England during the holiday period that extends through next Sunday. The organization predicted automobile traffic would be up 3.9 percent over last year, citing declining fuel prices and other factors, and that motorists as a result would face delays.

“We always advise people to leave earlier,” said Mary Maguire, Massachusetts spokeswoman for AAA New England. “And we always advise them to check weather forecasts.”

Michael Verseckes, a spokesman for the state Department of Transportation, said drivers who want to stay on top of traffic conditions can sign up for the state’s 511 traveler information service to receive alerts, or log into its Traffic Cameras web page.

Roadwork along portions of the shared highway of Route 128 and I95, and on I95 north of where it splits from 128 in Peabody will remain a fact of life for motorists well beyond the holiday period.

The state has projects on Route 128/I95 in Waltham, and from South Bedford Street in Burlington into Woburn; and along I95 in Peabody, Danvers, Topsfield, Middleton, and Boxford.

Begun in April 2010, the $22.7 million project in Waltham involves the resurfacing of a 4.1-mile stretch of the highway and ramps from the Weston line to the Lexington line. The work, which is being carried out by J.H. Lynch and Sons, also involves guardrail upgrades, construction of a new median, drainage improvements, and the building of a few detention ponds along the highway.

The project, 50 percent complete, is expected to be finished in the spring of 2013, according to Verseckes.

The $14 million project in Burlington and Woburn involves resurfacing about two miles of roadway, as well as replacing guardrails, cleaning and rebuilding drainage structures, and resetting granite edging where needed.

There will also be resurfacing and improvements to two bridges in Burlington.

The project, which is being undertaken by Aggregate Industries, is about 15 percent done, with the work targeted for completion in the fall of 2013.

“Route 128 is such a major arterial roadway,” Verseckes said by e-mail.

He said the two projects are undertaken to bring the road in those areas “up to a standard that drivers expect it to be, but also a standard that can accommodate the heavy volume as best as it can.”

Most of the construction work for both projects occurs between 9 p.m. and 5 a.m., with no work scheduled from Friday night to Monday morning during summer.

While neither project has been the source of unusual delays, Verseckes said “speeding through work zones . . . has been a problem.”

He said his agency is reminding drivers to slow down and travel safely through those construction areas, whether or not work is active at the time.

The projects are both being funded with 80 percent federal dollars and 20 percent state money.

The recently begun I95 project in Peabody, Danvers, Topsfield, Middleton, and Boxford is a $5 million job that involves resurfacing the road and installing guardrails and pavement markers.

Construction is scheduled 9 p.m. to 5 a.m.

The work, which is being carried out by Brox Industries, is expected to be completed next summer.

As early as the next few weeks, meanwhile, the Department of Transportation, is to begin replacing highway signs on Route 128 from Wellesley to Lexington.

Road Safe Traffic Systems, of Avon, will undertake the $4.5 million project, which is being funded with 80 percent federal and 20 percent state money.

And the state is preparing to undertake the construction of an additional lane on each side of Route 128 in Needham and Wellesley, the final leg of its overall Add-A-Lane project along the southwestern end of Route 128.

Design work is 75 percent complete, with construction to begin by late summer 2013.

The work will extend for 3.5 miles from north of the commuter rail line in Needham through the Route 9 interchange in Wellesley.