Drivers should brace for weekday traffic behind the MGM Grand and Tropicana casino-resorts on the Las Vegas Strip through Nov. 20 and again in January for sewer line work. A spokeswoman for the Clark County Water Reclamation District said work that started Monday will affect the Tropicana Avenue and Koval Lane intersections with the closure of an inside northbound lane on Koval to about 300 feet north of Tropicana and two left turn-lanes on southbound Koval squeezed down to a single turn lane.