Lexington, Ky. — A&W Restaurants posted double-digit, year-over-year sales in May, with some franchise locations doubling their sales. Other burger chains, on average, managed only a 2% increase, according to Black Box Intelligence. The iconic brand’s performance comes as it reduces royalties for new franchisees. The incentive program lowers royalties in the first year of all new development agreements from the standard 5% to 3%. Second year royalties are 4%. Initial fees on multi-unit agreements also are being discounted. “The incentives give franchisees extra cushion in their first few years …