RICHMOND — The main road into town, Route 197, will be closed for about a week starting next Monday.

A contractor working for the state Department of Transportation must close both lanes of the busy road to replace a large culvert where Route 197 passes over Baker Brook, just before the Richmond Business and Manufacturing Center.

The work will essentially split downtown Richmond from Interstate 295, at least via the road most motorists usually take between the two.

A detour will be established around the site. Motorists coming off Interstate 295 who want to get to downtown Richmond will have to head in the opposite direction they would normally go, about a mile to U.S. Route 201. The roughly three- to four-mile detour goes right onto Langdon Road, and right onto Alexander Reed Road, which leads back to Route 197, below the construction site and Main Street.

“It is a fairly heavily traveled corridor, but we don’t expect major traffic delays because of this,” said Ted Talbot, spokesman for the state Department of Transportation. “It shouldn’t prohibit folks from getting where they need to go.”

Talbot said there’s a good chance the work could finish early, depending on the weather, but for now the road is scheduled to be closed from Monday, Aug. 6 to Friday, Aug. 10.

The $211,000 project will be done by Richmond-based contractor Wyman & Simpson.

The project was initially scheduled for last summer, but was halted by the department, in part because town officials complained that locals had not been given enough warning that the closure was coming.

So this summer, transportation officials informed the town two weeks before the work was to begin of the coming start date. Message boards were activated at the site last week, informing motorists the road will be closed to traffic.

“The project manager has been in contact with the town all summer,” Talbot said. “Signs are up now, and will remain up, with additional detour signs to follow.”

Talbot said officials’ reaction to the apparent lack of prior notice last summer was not the only reason the project was delayed. He said the work also had to be coordinated with the Richmond Utility District, which has sewer and water lines on top of the culvert that is being replaced.

Talbot said both lanes of the road will be shut down and the road closed, rather than have the work done one lane at a time while the other lane remains open. That’s because of the tight confines of the site and the amount and size of equipment needed to do the work, he said. The work will take place during the daytime.