Helpful Hints from joeeze: Why the grocery express lane may not be your fastest checkout option

High school math teacher Dan Meyer wrote in a September 8, 2009 blog post, "[At express checkout] You attract more people holding fewer total items, but as the data shows... when you add one person to the line, you're adding 48 extra seconds to the line length... without even considering the items in her cart. Meanwhile, an extra item only costs you an extra 2.8 seconds. Therefore, you'd rather add 17 more items to the line than one extra person!"

Video here.