Anyone shopping for new or used cars likely will notice that automotive jargon seems to be chock full of ACRONYMs (Alphabetically Coded Reminders of Names You Misremember). A few may come to mind, such as EFI (Electronic Fuel Injection), ABS (Anti-lock Braking System), TPMS (Tire Pressure Monitoring System) and ESC (Electronic Stability Control), but that’s just the first spoonful of automotive letter soup.
In considering some of the latest active safety systems, FCW (Forward-Collision Warning) and PCS (Pre-Collision System) come to mind, usually in conjunction with AEB (Autonomous Emergency Braking) or APS (Automatic Panic Swerve). OK, we made that last one up, but Toyota calls their system PASA (Pedestrian-Avoidance Steer Assist).
So, how do forward-collision warning and other active systems work to keep drivers, pedestrians, cyclists and wildlife safe?
Why Do We Need Forward-Collision Warning?
Basically, the forward-collision warning system is designed to be more alert than its driver. All drivers must face the fact that, while the human brain is capable of thinking of many things at once, it’s difficult to focus on a single task. Scientifically speaking, though, there’s really no such thing as “multi-tasking” – it’s more like when multiple programs slow down your smartphone or computer – and studies have proven that drivers focused on things other than driving are more prone to get into a crash.
A University of Iowa study discovered that just talking with a passenger slowed the driver’s reaction time to new road and traffic situations by 40 ms (40/1,000ths of a second). This doesn’t seem like much time, but this “cognitive load” increases the reaction delay with every new distraction, upward of 100 ms in some cases. For comparison, it takes 300 ms to blink your eyes, around 500 ms to sneeze, about 1,000 ms to change the radio station (a whole second), and 5,000 to 8,000 ms (this sentence took about that long to read) to read a text message. At 60 MPH, a lot can happen in just a couple seconds, and a mere 40 ms delay in reaction can be the difference between a crash and successful evasion.
The National Highway Traffic Safety Administration (NHTSA) attributes at least 10 percent of traffic fatalities to distracted driving, and many states have implemented rules on distracted driving. Still, even when we’re paying attention to the road, “cognitively unloaded,” if you will, it turns out that the human brain just isn’t that great at recognizing and reacting to sudden road and traffic changes, such as a car pulling out of a parking spot into traffic, a child chasing a ball into the street, or a wild animal crossing the road. On the other hand, computers can’t be distracted, don’t tire out, and are excellent at noticing (detecting), anticipating (programming), and reacting (braking or evading).
How Does Forward-Collision Warning Work?
Equipped with sensors such as RADAR (Radio Detection and Ranging), LIDAR (Light Detection and Ranging), SONAR (Sound Navigation and Ranging) and cameras, forward-collision warning systems constantly monitor other vehicles, cyclists, pedestrians, animals and stationary objects. Sophisticated programming predicts what a moving object is bound to do once it’s entered the field of view. In just milliseconds, FCW can determine whether a collision is imminent. At that point, FCW can alert the driver, such as with an audible alarm or haptic steering buzz. The speed and focus of FCW systems give drivers the advantage of a few more milliseconds of reaction time, which can prevent a crash or at least reduce the severity of one.
Active safety systems go even further. Some will cinch up the seat belts or boost brake pressure to help the driver stay in control and maximize braking. If a crash is unavoidable, some advanced safety systems can act independently of the driver. Autonomous emergency braking can significantly reduce the speed of the vehicle, preventing a crash or reducing the severity of the impact. Recognizing that up to 40 percent of crashes would be unavoidable by AEB alone, Toyota PCS/PASA can use the electronic power steering to swerve to avoid the obstacle.
Where Can You Find Forward-Collision Warning?
Practically every automaker has developed some form of FCW system, but it’s good to note that it’s a relatively new technology. Most new technology options find their way into luxury cars and higher trim levels, but more cars every year are being equipped with them. While shopping new and used cars, expect to pay more or move to an unfamiliar make or model to find vehicles with FCW. It’s likely that such technology will trickle down to the affordable market, and it wouldn’t surprise us if NHTSA mandated it, much like TPMS and ESC, required since 2007 and 2012, respectively.
Of course, FCW and any other active safety system are absolutely no substitute for unsafe driving practices, such as driving distracted, driving drowsy or following too closely.