Buoyed by stronger same-store sales and customer traffic levels, the National Restaurant Association's Restaurant Performance Index (RPI) hit a 14-month high in May. The RPI – a monthly composite index that tracks the health of and outlook for the U.S. restaurant industry – stood at 101.8 in May, up 0.9 percent from April and the third consecutive monthly gain. May also represented the third straight month that the RPI surpassed the 100 level, which signifies expansion in the index of key industry indicators.

"The May increase in the Restaurant Performance Index was driven by broad-based gains in the current situation indicators, most notably positive same-store sales and customer traffic results," said Hudson Riehle, senior vice president of the Research and Knowledge Group for the National Restaurant Association. "In addition, restaurant operators remain optimistic about continued sales growth and a majority plan to make a capital expenditure in the next six months."