Why the Queen doesn't need a passport or driving license

At this point, it's almost common knowledge that the Queen is not required to own a passport or driving licence, but the reason why has rarely come to light. 

The reason is pretty straight forward. According to the official royal website, 

"As a British passport is issued in the name of Her Majesty, it is unnecessary for The Queen to possess one. All other members of the Royal Family, including The Duke of Edinburgh and The Prince of Wales, have passports.

In realms (Commonwealth countries where The Queen is Sovereign), a similar formula is used, except that the request to all whom it may concern is made in the name of the realm's Governor-General, as The Queen's representative in that realm. In Canada, the request is made in the name of Her Majesty by the Minister of Foreign Affairs." 

This reason also applies to her lack of drivers licence, but don't worry, Her Majesty is trained as not only a driver, but a mechanic too!