WASHINGTON – The National Restaurant Association’s Restaurant Performance Index (RPI) fell 0.6 percent to 100.5 in December due to softer same-store sales and customer traffic levels.

“The December decline in the RPI was due to a dip in the current situation indicators, which in turn was partly caused by inclement weather in large parts of the country,” said Hudson Riehle, senior vice president of the research and knowledge group for the association. “Despite the softer December results, restaurant operators remain generally optimistic about business conditions in the months ahead.”

The RPI is made up of two components, the current situation index and the expectations index. In December the current situation index stood at 99.5, down 1.7 percent from November and the lowest level in 10 months.

Forty-one percent of restaurant operators said they experienced a decline in same-store sales in December, up from 29 percent in November. Restaurant operators also said softer customer traffic levels in December. Thirty percent of restaurant operators reported customer traffic growth between December 2012 and December 2013, down from 47 percent who reported a traffic gain in November. In comparison, 46 percent of operators reported a decline in customer traffic in December, up from 35 percent in November.

The RPI’s expectation index, on the other hand, rose 0.4 percent in December to 101.5. Restaurant operators are generally positive about sales expectations in the coming months. Thirty-eight percent of restaurant operators expect to have higher sales in six months (compared to the same period in the previous year), unchanged from the proportion who reported similarly last month. Meanwhile, 13 percent expect their sales volume in six months to be lower than it was during the same period in the previous year, while 49 percent expect their sales to remain about the same.

In comparison, restaurant operators are somewhat less optimistic about the direction of the economy. Twenty-eight percent said they expect economic conditions to improve in six months, while 16 percent expect the economy to worsen. The remaining 56 percent expect economic conditions to remain generally unchanged in the next six months.