The Beast
The presidential limo nicknamed the ‘Beast’, goes everywhere the president goes—without exception. The reason for this is that the Secret Service will be better able to maintain the safety of the POTUS during vehicular transport. When the POTUS arrives, the limo is there waiting for him when he lands at his destination, to carry him to wherever he needs. However, the limo, a Cadillac, does not actually travel with the president. In actuality, it is sent ahead of the president, transported aboard a military cargo plane. Since it is ahead of the president the limo can be waiting and ready on the tarmac when the president arrives.
Image: preslimousa.com