WASHINGTON — Despite softer sales and a net decline in customer traffic during the month of April, the National Restaurant Association’s Restaurant Performance Index (R.P.I.) stood above 100 for the second consecutive month. Standing at 100.4 in April, the R.P.I. was virtually unchanged compared with March when it was 100.5. Index levels above 100 indicate expansion of key industry indicators, according to the N.R.A.

“Although the sales and traffic indicators softened somewhat from their March performance, restaurant operators remain optimistic that business conditions will improve in the months ahead,” said Hudson Riehle, senior vice-president of the Research and Knowledge Group for the Association. “In addition, restaurant operators reported a positive outlook for staffing gains, as well as continued plans for capital expenditures in the coming months.”

The R.P.I. features two components: the current situation index (C.S.I.) and the expectations index (E.I.). The C.S.I. stood at 99 in April, unchanged from the March level. After reporting net positive same-store sales in March for the first time in 22 months, restaurant operators reported softer sales results in April.

Thirty-nine per cent of restaurant operators reported a same-store sales gain between April 2009 and April 2010, down from 43% of operators who reported higher sales in March.

The E.I. stood at 101.8 in April, a slight decline from 101.9 in March. The N.R.A. said restaurant operators remain optimistic about sales improvements in the months ahead. Forty-seven per cent expect to have higher sales in six months, down from 50% who reported similarly in March.