Photo by specialkrb.
When choosing which line will be the fastest, it might surprise you to learn that the "express" lane may not always be the best choice. Meyer took a scientific look at supermarket checkout times and came to the conclusion that the number of people in line adds more to the wait time than the number of items each person has in their cart.
[W] hen you add one person to the line, you're adding 48 extra seconds to the line length (that's "tender time" added to "other time") 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!
Of course, other variables, both known (dedicated bagger) and unknown (payment type, coupons, cigarettes) affect on the speed of the line, but this is a good rule of thumb to use as a baseline. To save time and money before you get to the checkout, try shopping every other week and make an organised list before you go shopping.
If you've got your own tricks for getting through the checkout lane in a hurry, let us know in the comments.