The Red Line between Harvard Square and Alewife stations will be shut down on Saturdays and Sundays for four straight weekends, starting on Nov. 17, according to the MBTA's website.
The last weekend of the closure will be Dec. 8 and 9.
During those weekends, bus service will replace trains between Harvard and Alewife.
The MBTA says the closures are taking place so the transportation authority can work on the Floating Slab Project. The Tufts Daily reports that floating concrete slabs rest on rubber disks and are designed to minimize vibrations and wear and tear in the tunnel.
This same section of Red Line experienced four months of weekend closures in late 2011 and early 2012 so the MBTA could begin substantial repair work in the tunnel, which opened in 1985.
At the time, the MBTA said it would be conducting a $35 million capital improvements program in the tunnel between 2012 and 2016, which includes replacing the third rail. So, expect more weekend closures over the next three years.
During the last round of weekend closures, some businesses in Davis Square were annoyed that the subway line, which brings visitors to the area's restaurants, bars and cafes, closed down over the holiday season. In response, the MBTA offered an advertising discount to Somerville businesses.
This time around, the four weeks of weekend closures will overlap with the beginning of the holiday season, but not the entire season.
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MBTA Offers Ad Discount to Somerville Businesses
MBTA Offers Advertising Discount to Somerville Businesses
Weekend Red Line Service Resumes This Weekend