The biggest factor for speed is the competency of the cashier. Many cashiers are tired and slow and don't care much about their jobs, you need to get in the lin

The biggest factor for speed is the competency of the cashier. Many cashiers are tired and slow and don't care much about their jobs, you need to get in the line with the energetic smiling cashier who is moving things along. Also, the self checkout lines can be incredibly fast or incredibly slow. If there is a problem you have to wait for a cashier to come fix it, and if the person in front of you gets confused it can take forever.