2008 Volvo V70 Owner's Manual - Page 162

173 04 Comfort and driving pleasure Driver Alert System-option Introduction The Driver Alert System is designed to help a driver who may be becoming fatigued or who is inadvertently leaving the lane. The Driver Alert System consists of two different functions that can be switched on together or separately. Driver Alert Control (DAC) Lane Departure Warning (LDW) When one or both of the functions has been switched on, it is in standby mode and is activated when the vehicle exceeds a speed of 40 mph (65 km/h). The function deactivates if speed goes under 37 mph (60 km/h). Both functions use a camera that is dependent on the road/lane being clearly marked by painted lines on each side. WARNING The Driver Alert system does not function in all situations and is designed to be a supplementary aid. It is not, however, intended to replace the driver's attention and judgement. Driver Alert Control (DAC)-general information This function is intended to alert the driver if his/her driving becomes erratic, such as if the driver is distracted or fatigued. A camera monitors the painted lines marking the lane in which the vehicle is traveling and compares the direction of the road with the driver's movements of the steering wheel. The driver is alerted if the vehicle does not follow the lane smoothly.