East Lyme — Town officials say they are working with the state Department of Transportation to mitigate expected traffic delays, as a Route 1 bridge replacement starts this week, and traffic backups have hit a high point near the Interstate 95 Exit 74 interchange while Costco developers rework on and off ramps.

Drivers have been taking back roads and alternate routes, including Route 1-Boston Post Road, to avoid the clogged area around Exit 74. But as a bridge between Lovers Lane and Heritage Road on Route 1 is set to be replaced, officials said they have prepared for further delays along the town’s main throughways, as well as on its series of collector roads.

The good news, according to Public Works Director Joe Bragaw, is that Exit 74 work should wind down by the end of this month in time for the bridge project to go into full swing after Labor Day.

Though the bridge project officially began Monday, according to a DOT announcement made last week warning of the replacement, planned road closures and alternating one-way traffic pattern with concrete barriers along Route 1 won’t go into full swing until after Labor Day, Bragaw said, helping alleviate expected traffic backups on the town’s busiest roads while Exit 74 changes are still underway.

The bridge will be closed completely for two weeks starting Oct. 14.

Both the Exit 74 and Route 1 road projects are not town projects.

“We were very particular with DOT and told them that they couldn't do the alternating one-way traffic until after Labor Day, until after summer traffic slows down,” said Bragaw. "They wanted to get going before that, but we said no way."

Bragaw has worked closely with the DOT employee overseeing the work, Brent Church, to help plan for the projects, as well as worst-case scenarios. Church was not immediately available for comment before Monday’s deadline.

The ongoing Exit 74 work, which include changing on- and off-ramps both southbound and northbound, come as Costco plans to open its East Lyme store in the coming months. According to Costco’s plans, Bragaw said Exit 74 on and off ramps will be extended into a T configuration on a frontage road running by Pools Etc., allowing drivers coming off the interstate to either turn left toward Costco or right toward Route 161 after a stop light. The northbound on-ramp entrance is also being altered, Bragaw said.

Costco’s roadwork changes are not part of a more extensive Route 161 widening and Exit 74 bridge replacement project also being planned by DOT. Construction for that project is anticipated to begin in summer or fall 2021, and is expected to last approximately three to four years, said DOT spokesman Kevin Nursick by email last month.

Bragaw said that besides limiting the duration of the Route 1 bridge project, DOT, in an effort to dissuade drivers from using Route 1, will set up several signs along I-95 — both in Old Lyme and throughout East Lyme — warning drivers to seek alternate routes and avoid driving on Route 1.

Route 1 will stay open for most of the project's duration with alternating one-way traffic patterns, while a total road closure will be limited to two weeks to avoid prolonged inconveniences for residents, Bragaw said.

Drivers during the road closure will need to use the town’s collector roads, including Lovers Lane, Dean Road and Society Road, to get from one side of town to the other. DOT will also provide a detour route, Bragaw said.

The Flanders Fire Department, located on Route 1 by East Lyme High School, has also worked on a coverage plan to keep its response times down while Route 1 is closed. Flanders Fire Chief Bill Rix said Monday that DOT will pay to have 24-hour fire and ambulance coverage on the western side of town where fire staff, a firetruck and an ambulance will be temporarily housed at the National Guard’s Stone Ranch Road facility to quickly respond to emergencies on that side of Route 1.

“Having fire engines and ambulances on both sides of the road closure will help us cut down on response times should an emergency happen,” Rix said. “This way, we won’t have to drive down and around I-95 to reach an emergency.”

The Flanders Fire Department will also be staffed around the clock during the two-week road closure, Rix said.

Though the roadwork is being staggered, both Rix and Bragaw acknowledged that traffic can’t ever be a perfect situation during construction — especially if an accident occurs along I-95. With that in mind, Rix said the fire department is already used to navigating bumper-to-bumper traffic along Route 1 when highway accidents do occur. He added that one-way traffic lights installed on Route 1 during construction can be controlled by oncoming firetrucks and ambulances during an emergency to turn the light red or green, as needed, allowing emergency vehicles to pass through the construction area without as much delay.

Still, Rix worried about drivers, especially truck drivers, ignoring road closure signs during anticipated traffic backups on the highway.

“It takes just one tractor trailer to ignore the road closure signs and we could have a big problem,” Rix said. “If the trailer traveled all the way down to the road closure, there would be no way for it to turn around. So there could be some big problems. We will see what happens.”

m.biekert@theday.com