Choosing the Fastest Checkout Counter - The Intrepid

Tuesday, September 29, 2009

Choosing the Fastest Checkout Counter

Simpsons Express Lane Marge and Apu

From The Simpsons episode "Homer and Apu:"

Apu: Mrs. Simpson, the express line is the fastest line not always. That old man up front, he is starved for attention. He will talk the cashier's head off...
Apu: Let's go to...that line.
Marge: But that's the longest.
Apu: Yes, but look: all pathetic single men. Only cash, no chitchat.

It turns out that Apu was only partially right; yes, the express lane isn't always the fastest, but the longest, regardless of who's in it, is usually the slowest.

According to a new mathematical study by Dan Meyer, a math teacher from Santa Cruz, California, on average, the number of people in line adds more to the wait time than the number of items each person has in their cart. "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," explains Meyer. "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!" So, it looks like it's always best to avoid the longest line, even when it's full of "pathetic single men."

Originally spotted at Lifehacker.