Vehicles operating in an autonomous mode (e.g., driverless) can relieve occupants, especially the driver, from some driving-related responsibilities. When operating in an autonomous mode, the vehicle can navigate to various locations using onboard sensors, allowing the vehicle to travel with minimal human interaction or in some cases without any passengers.
Similar to human beings making various decisions while driving, an autonomous vehicle always has to make instant driving decisions according to the actual surrounding environment, which includes, but is not limited to, a stop-controlled junction or intersection, yield-controlled intersection, etc. Such environment often creates driving difficulties (e.g., a deadlock) as it may be difficult to determine which vehicle, for example, has the right-of-way. Human beings, however, can easily resolve the difficulties by communicating with each other with gestures (e.g., hand motions). Unfortunately, such may be challenging for autonomous vehicles.