The Holiday Checkout Line Strategy

Is there a formula for picking the fastest checkout line at a retail store?

According to a graphic from The Wall Street Journal, simple arithmetic could tell shoppers the expected wait time in every checkout line.

According to the article, average wait time equals the number of shoppers already in a line divided by the rate of new shoppers entering the line. For example, 10 customers in line divided by two new customers entering the line per minute equals a wait time of five minutes.

Where have you experienced the worst checkout lines? Tell us in the comments.