A portion of Interstate 40 will be reduced to one lane beginning Friday night and continuing through the weekend. Tennessee Department of Transportation Crews will be repairing the Elm Hill Pike bridge that crosses over the interstate at mile marker 217 beginning at 8 p.m. Three of the four lanes on I-40 westbound will be closed during the repairs. No lanes on Elm Hill Pike will be closed. Motorists are encouraged to use State Route 840 as an alternative route. Officials said the repairs stem from an oversized vehicle that struck the bridge. The lane closures will remain in effect through the weekend. All lanes are expected to reopen before Monday morning's rush hour.