The closure will be from 8 p.m. Friday until at least 8 p.m. Sunday.
Improvements to the Roaring Brook Railroad crossing are the reason behind the planned detours.
The state Department of Transportation will post signs redirecting Saw Mill River Parkway.
Local motorists may have limited access to points between Southview and Bedford roads, police said.
For more information, call the New Castle Police Department at 914-238-4422.
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