WASHINGTON — Improving same store sales and customer traffic levels were both cited as reasons why the National Restaurant Association’s Restaurant Performance Index climbed to 100.7 in February, a 0.4% increase compared with the January R.P.I.

“Restaurant operators reported positive same-store sales and customer traffic results in February, after January’s results were dampened by extreme weather conditions in many parts of the country,” said Hudson Riehle, vice-president of the Research and Knowledge Group for the Association. “In addition to improving sales and traffic indicators, restaurant operators’ outlook for capital spending hit a 40-month high, while their expectations for staffing growth rose to the highest level in nearly four years.”

The R.P.I.’s current situation index, which covers same-store sales, traffic, capital expenditures and labor, stood at 99.4 in February, a 0.9% increase compared with January. Restaurant operators reported improvement in same-store sales in February. Forty-nine per cent reported a same-store sales gain between February 2010 and February 2011, up from 39% of operators who reported higher same-store sales in January. In comparison, 37% of operators reported a same-store sales decline in February, down from 44% who reported lower sales in January.

The R.P.I.’s expectations index, which includes same-store sales, business conditions, employees and capital expenditures, rose to 101.9 in February, a slight increase compared with the January level of 101.8. The expectations index showed that restaurant operators remain optimistic that sales levels will improve in the months ahead. Forty-eight per cent expect to have higher sales in six months (compared with the same period in the previous year), up slightly from 47% who reported similarly last month. In comparison, 12% of restaurant operators expect their sales volume in six months to be lower than it was during the same period in the previous year, down from 14% who reported similarly last month.