2011 Toyota Prius Owners Manual - Page 251

2-4. Using other driving systems Driving in vehicle-to-vehicle distance control mode This mode employs a sensor to detect the presence of vehicles up to approximately 400 ft. (120 m) ahead and to judge the distance between your vehicle and those the vehicle ahead of you. Note that vehicle-to-vehicle distance will close in when traveling on long downhill slopes. 2 When driving 225 PRIUS_U (OM47685U) DVD