Overnight demolition of the Bath Viaduct is scheduled to wrap up next week, much to the relief of residents who have endured nighttime disruptions for almost a month.

People have lost sleep and adjusted their schedules as workers tear apart the massive concrete and steel overpass that runs through the middle of downtown Bath. The two-lane elevated highway carries Route 1 over the city center and Bath Iron Works shipyard and onto the Sagadohoc Bridge across the Kennebec River.

Work on the $12 million replacement started this spring and won’t be completed until Memorial Day 2017.

“It is very frustrating, it is annoying to lose sleep,” said Chelsea Hinds, who lives in an apartment on Middle Street, near the viaduct project. Work crews typically start at 7 p.m. and use giant jackhammers to loosen up parts of the bridge before pounding it with a wrecking ball. More jackhammers break apart the debris.

The demolition continues until crews start clearing the site in time for the morning rush hour. Hinds said the noise wakes her up several times a night, and she is lucky to have a job with flexible hours so she can catch up on sleep.

When demolition started, Hinds said she went outside for the first few nights to watch the spectacle. Some people park nearby to watch the construction zone at night, but the novelty wore off for Hinds long ago.

“It is not terribly interesting anymore, just loud,” she said. “I am just holding onto the fact that the constant vibration, noise and dust should be over soon.”

Hinds is far from the only person affected by the project. The Maine Department of Transportation hasn’t kept a record, but it is fair to say there have been “numerous” complaints to the department, city of Bath and Bath Police Department, said transportation department spokesman Ted Talbot.

“Obviously we regret the inconvenience this has caused, but we believe in the end this is a better schedule for everyone,” Talbot said.

Demolition of the 58-year-old overpass started Oct. 11. Crews had to work at night so they did not disrupt daytime traffic, said Glenn Philbrook, a Maine DOT project engineer. Construction is at least a week ahead of schedule and regular nighttime work should be completed by Nov. 13, Philbrook said. The project started in May and the viaduct was closed last month.

“The original viaduct took 729 days to build, we are giving the contractor 229 days to tear it down and build a new one,” Philbrook said. “This accelerated project was due in part to minimize impact on businesses, residents and tourism. As a result, we had to give contractors latitude to work weekends and nights,” he said. The department warned residents early on about noise and disruption that would result from the construction, he said.

The Bath Viaduct was built in 1958 and resurfaced in 2006. City and state officials planned to replace the span for years because its structure was deteriorating. About 18,000 vehicles use the viaduct daily, according to the Department of Transportation. In April, the overpass was briefly closed to repair missing and broken bolts and damage to a guardrail. The work became necessary after a driver lost control in icy conditions and broke through the guardrail on the overpass and fell onto a pickup truck on the road below.

The project was expected to create traffic disruptions, but so far serious back-ups have been limited to westbound lanes during the morning rush hour, Bath Public Works Director Peter Owen said. Some of those tangles have caused traffic to back up over the Sagadahoc Bridge and almost into Woolwich on occasion.

Westbound traffic is rerouted along Vine Street and Leeman Highway and eastbound vehicles take Commercial Street while the viaduct is closed. During nighttime construction, additional detours take westbound vehicles onto Vine and Washington streets.

“Like any construction project there are bumps and hurdles in the process,” Owen said. “Overall, we have been happy with the way the state has been managing it.”