Distracted driving is one thing, but driving while you are drowsy is another matter entirely. The engineers at Mercedes have developed a new system to monitor the drowsiness of a driver and provide an alert before the driver falls asleep and causes a crash.
Since Mercedes did the tuning to the system, you shouldn't expect many false alerts. A very precise steering shaft sensor now monitors inputs to a tenth of a degree to help determine a driver's reaction time and the severity of corrections made to keep the car on course. Several other factors are monitored, but not the driver's eyes. Other attention monitoring systems focus on the eyes, but those systems do not work for people wearing glasses.
It takes 20 to 30 minutes of normal driving for the car to learn your individual driving habits and determine which inputs are normal. After that, the Mercedes will monitor your driving and give an audible and visual alert when it detects a period of no corrections and then an over-correction from the driver.
Since the attention assist system is designed to provide no false alerts, it may actually give an alert too late to be effective. The demonstration we witnessed gave an alert that was a bit too subtle to be convincing. Mercedes is clearly walking a fine line between being helpful and being annoying and the system is tuned to be minimally intrusive during normal driving. Ideally, drivers would recognize a dangerous situation and take a break before the warning kicks in.