Weak tourism in Las Vegas is creating a snag in plans for major road construction. Nevada Department of Transportation director Susan Martinovich says part of the money from hotel room taxes was to go toward a $250 million expansion project on I-15 between Blue Diamond and Tropicana. But the Convention and Visitors Authority wants to hold off on the start of payments until at least January. The authority is mandated by law to support road bonds, but room tax revenue for the current fiscal year has been projected to take a $53 million hit.