Should some radio button of a shipping method be pre-selected on checkout page?

1. Should radio buttons be pre selected?
2. What is a radio button selection?

Should radio buttons be pre selected?

Always Offer a Default Selection

One of the 10 heuristics of UI design says that users should be able to undo (and redo) their actions. This means enabling people to set a UI control back to its original state. In case of radio buttons this means that radio buttons should always have exactly one option pre-selected.

What is a radio button selection?

Radio buttons are used when there is a list of two or more options that are mutually exclusive and the user must select exactly one choice. In other words, clicking a non-selected radio button will deselect whatever other button was previously selected in the list.