Human emotion metrics for navigation plans and maps: Imagine choosing not just the quickest path to your destination but the one that is most likely to lift your mood. Patent no. 8,364,395 fuses advances in mapping and traffic data with those in mood detection to form an emotionally intelligent navigation system.

Route-planning devices and maps already allow users to choose a path that avoids tolls or traffic jams. And some technologies can gauge mood: microphones detect vocal stress in drivers asking for directions or screaming expletives; sensors detect a driver's pulse and sweaty palms on the steering wheel; and software mines social-media streams for users' emotions and locations.

A new device, designed by IBM researchers, could help tourists navigate unfamiliar cities, avoiding protests and road-rage incidents but taking in buzz-generating restaurants or tranquil scenery. Emoticons displayed along the routes would serve as guides.

The device factors in recent history. “You can choose a destination where people are happiest now or where people over the last week” have been happy, says co-inventor Paul B. French, a systems architect at IBM. If an area cheered visitors up, the system would classify the route as mood-enhancing. “The change of mood,” he says, “is key.”