The president is never on leave, and even when POTUS is on vacation, the demands of the office are not far off. World events can arise and require major decisions at any time, so the President is kept a short distance from communications at all times. The limo is something of a mobile extension of the Oval Office. The cars are equipped with state-of-the-art satellite communications, so contacting the Joint Chiefs of Staff, military generals, or the vice president is always an option.
Communications details, like so many other facets of the limo, are highly classified. However, there are some safe guesses along with a few details that give a good idea of what’s on board. In an episode of Comedians in Cars Getting Coffee, President Obama tells Jerry Seinfeld, “I could call a nuclear sub right here,” and adds, “That’s a cool feature. Pus seat warmers. The car is equipped with secure communication lines but is also being followed by a vehicle dubbed The Roadrunner, according to The Drive. Its responsibilities are to carry the equipment that establishes the secure satellite connections and it is also said to be equipped with other equipment such as radars to monitor the surroundings and see any possible incoming threats.