This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
A LinkedList implements the Queue interface as well as the List interface (ArrayList doesn't), but to get it to behave like a queue you've got to use the methods in that interface. You're just using the List interface - adding values and then iterating through them in order. All classes implementing List ought to behave the same way doing that.