CHICAGO - Drive-thru options at restaurants continue to deliver convenience to time-strapped customers, according to new data released by The NPD Group, a market research company.

According to NPD??s CREST service, which tracks how consumers use restaurants and other foodservice outlets, 12.4 billion visits were tallied at QSR drive-thrus in 2011, a 2% increase over the prior year.

While carry-out represents the majority of QSR visits across all restaurant segments, drive-thru is the ordering method of choice at hamburger (57%), Mexican (40%), and chicken QSRs (38%).

"Drive-thru customers?? expectations are straightforward - take down my order accurately and give me my food fast," said Bonnie Riggs, restaurant industry analyst at NPD. "To address consumer needs by having a drive-thru operation requires ample real estate and a complex mix of technology, logistics, and time management principles. It is really a very well-orchestrated dance."

Riggs said most drive-thru complaints concern taking too much time, with getting the wrong order, not understanding the speaker voice, and waiting in line other reasons that detract from the drive-thru experience. She said some QSRs have been addressing those concerns, adding multiple lanes, improved ordering systems, staff training, and other advances.

"In addition to offering speed and convenience to customers, the drive-thru operation is important to fast food restaurants?? bottom line, which is why fast casual and other quick service categories are planning drive-thrus," Riggs said. "A successful drive-thru operation translates to higher customer satisfaction, repeat business, and more profit. "