For the practiced user, a marking menu makes for a very powerful, and quick means of accessing specific commands, without following a typical click path. This ancillary menu system is accessed by a three finger tap and hold gesture. Activating this menu completely takes over the screen, and divides it into quadrants, each representing one of the four main content areas of the interface. The driver may then swipe into one of the quadrants, revealing submenu items for that section. A directional swipe then activates the submenu item. This all sounds complex, but with a bit of repetition, gestures soon become ingrained in muscle memory. For example, to access the phone book from anywhere in the application, the driver need only tap with three fingers, swipe up, and swipe back down, keeping their eyes on the road.