Drivers Alert Systems

Drowsiness Detection: Waking Up Fatigued Drivers

A drowsy driver who could benefit from a driver alert system yawns in his car.
valentinrussanov / E+ / Getty

Driver alert systems offer a way to reduce the likelihood that a drowsy or fatigued driver will cause an accident due to sluggish reactions or dozing off. These systems are designed to detect the telltale signs of a drowsy or impaired driver, and then provide an alert or take some type of corrective action. Each system uses different methods of detection and correction, but they all share that same general purpose.

The Trouble With Drowsy and Impaired Drivers

Research has found that fatigued and drowsy drivers suffer from increased reaction times, and that a large number of both fatal and non-fatal crashes take place during the nighttime and early morning hours when drivers are less alert. With these two pieces of information, it's reasonable to assume that a general increase in driver alertness could potentially save lives.

While an NHTSA study concluded that adequate sleep and proper education on the dangers of drowsy driving are the best solutions to the problem, the reality is that drowsy and impaired drivers get behind the wheel every day. For those drivers, an effective driver alert system can easily be the difference between an uneventful drive and a catastrophic accident.

How Do Drivers Alert Systems Work?

Drivers alert systems are closely related to lane departure warning systems, in that most of them function by keeping visual track of lane markings to identify any deviations from the lane. While lane departure warning systems are designed to prevent deviation under any and all circumstances, drivers alert systems are specifically aimed at identifying signs of driver fatigue.

Rather than triggering only when a vehicle is in danger of straying from its lane, these systems look for the sort of erratic movement typically associated with an impaired driver.

Other systems take it a step further by monitoring the driver’s eyes and face for signs of drowsiness. If the system determines that the driver is having trouble staying awake, it may take corrective action.

The simplest driver alert systems are typically mounted to the driver's head, like an earpiece, and use a simple motion or tilt sensor. If the driver's head nods, the device will usually sound an alarm.

Specific Driver Alert System Implementations

Each OEM that offers a drivers alert system has its own take on this technology, but the most common configuration uses a front-facing video camera that is mounted so that it can track both the left and right hand lane markings.

Some of these systems can also function if only one lane marking is visible. By tracking the lane markings, or examining other inputs, the drivers alert system can detect signs of fatigued driving.

Some drivers alert systems use complex algorithms to differentiate between intentional movements and the sort of drifting and jerky steering typically associated with a fatigued driver. Other systems have sensitivity controls that the driver can adjust, and most can be switched of manually.

In addition to monitoring the way that a car is being driven, some drivers alert systems can also monitor the driver by looking for signs of drooping eyelids, slackened facial muscles, or other telltale signs of drowsiness.

These features aren’t as widely available, though a number of OEMs are working with advanced facial recognition technology for future implementations of their drivers alert systems.

When a drivers alert system detects signs of driver fatigue or drowsiness, a number of things can happen. Some of these systems provide a multi-tiered method, which increases in severity as time passes.

These systems will typically start off by sounding some type of buzzer or chime and illuminating a light on the dash. If the driver stops driving erratically at that point, the system will typically shut off the nag light and reset itself. However, if the signs of fatigued driving continue, the drivers alert system may sound a louder alarm that requires some sort of driver interaction to cancel.

Some drivers alert systems eventually progress to an alarm that can only be cancelled by pulling the vehicle over and either opening the driver’s door or shutting the engine off.

Who Offers Drivers Alert Systems?

Drivers alert systems are offered by a number of OEMs, and others have plans to implement their own technologies, but not every automaker offers the feature in every territory. In many cases, drivers alert systems are rolled into packages that also include various other crash avoidance technologies.

Some of the OEMs that offer some type of drivers alert system include:

  • Ford (Driver Alert)
  • Mercedes-Benz (Attention Assist)
  • Toyota (Driver Monitoring System)
  • Volkswagen (Fatigue Detection System)
  • Volvo (Driver Alert Control)

Are There Any Aftermarket Drivers Alert Systems

While there are a lot of OEMs working on drivers alert technologies, similar systems are available to the owners of older vehicles through the aftermarket. Some aftermarket drivers alert systems include:

  • Anti Sleep Pilot
  • Takata SafeTrak

There are also simpler aftermarket solutions, like the Nap Zapper, that a driver can wear on his head. These devices detect specific movements, such as when a drowsy driver’s head nods, and respond by sounding a loud alarm.

While devices like these are decidedly low tech in comparison to real drivers alert systems, and efficacy will vary from one driver to another, they are also significantly less expensive.