From antilock brakes to full stability to collision mitigation technologies, today’s commercial vehicle driver assistance systems are engineered to help commercial vehicle drivers do their job more safely. And getting the most out of these driver assistance technologies requires a properly maintained vehicle paired with the right brakes for optimal safety, performance, and return on investment.
Let’s dig into this by beginning with a look at some of today’s leading-edge advanced driver assistance system (ADAS) origins and capabilities, starting with antilock braking systems (ABS). ABS has been around for several decades now and operates by using wheel speed sensors communicating with an electronic control unit (ECU) that helps prevent wheels from locking up when they lose grip during braking. ABS has been mandated on new tractors and trailers since the late 1990s and forms the base technology upon which full-stability systems like Bendix® ESP® are built. Full stability, in turn – mandatory on new commercial vehicles in the U.S. since 2017 – is the base for collision mitigation technologies like the Bendix® Wingman® family of products.
Now, let’s remember why we keep developing and refining these systems: Safety technologies complement safe driving practices. While it’s absolutely crucial to remember that no commercial vehicle safety technology replaces proactive, comprehensive driver training and a skilled, alert driver exercising safe driving techniques, ADAS effectiveness in helping enhance roadway safety is clear. A 2020 article by the Insurance Institute for Highway Safety (IIHS) concluded that “Forward collision warning and AEB (autonomous emergency braking) reduced rear-end crashes – the specific type of collision they’re designed to prevent – by 44% and 41%, respectively.”
And since automatic brake applications play a key role in each of these technologies – ABS, full stability, and collision mitigation – it follows that the actual stopping power at each wheel-end will directly affect their performance. At Bendix, we’ve found that properly maintained air disc brakes are best for the job.
The Real-World Difference of Air Disc Brakes
ABS, full stability, and collision mitigation systems are all fully compatible with drum brakes – but in order to maximize your investment and enhance safety most effectively, you should consider spec’ing air disc brakes. Why? Because they provide shorter stopping distances, particularly after repeated stops, and their straighter, more stable stops (compared to drum brakes) help drivers remain in control.
Take a look at the chart below. At a base level, side-by-side in a one-stop application, a tractor-trailer combination equipped with air disc brakes on all wheel ends will stop 20 feet shorter than the same vehicle combo equipped with all drum brakes. At 50 mph, this is 0.27 seconds of extra time for ADAS system to potentially react and/or driver intervention. It doesn’t sound like a lot of time, but when you consider the average car length of 14.7 feet, that could be the difference between a collision and one you potentially mitigate or avoid altogether.
Air disc brakes’ advantage becomes even more apparent over repeated braking since drum brakes experience fade as they heat up. As heat builds up during brake applications, thermal expansion occurs—the drum expands out away from the brake shoes, resulting in extended stopping distances. Over a series of 20 stops, the tractor/trailer fully equipped with ADB gains 1.64 seconds of reaction time compared to drum brakes, equating to a dramatic 120-foot difference in stopping distance. You can also see an ADB vs drum brake fade comparison in this video on our YouTube channel.
This is also a good place to emphasize the importance of selecting the right replacement components: Bendix pads and rotors are designed and tested to work in concert to achieve the best performance. This is what we call the “friction couple”. Aftermarket parts that don’t come from the OE may extend stopping distance performance or lead to excessive rotor or pad wear, resulting in more frequent brake jobs, higher replacement part costs, and more downtime.
Everything Is Connected
Bendix® Wingman® Fusion™ – our flagship advanced driver assistance system – is built on the foundational technology of the Bendix® ESP® Electronic Stability Program full-stability system. This enables it to potentially assist drivers in crash situations, including rollovers and loss-of-control scenarios.
Fusion gathers input through its radar, camera, and the Bendix ESP braking system, combining and cross-checking the data from sensors that are working together and not just in parallel. This combination helps to enable very capable active braking features, including: • Automatic emergency braking (AEB), which applies up to full tractor braking power while pulsing the trailer brakes as a result of the system recognizing a potentially threatening forward vehicle (moving or stationary) • Multi-lane AEB that may continually apply the brakes after an AEB event has started—when a driver steers into an adjacent lane, and there is another vehicle in that lane, potentially causing a threat • Highway Departure Alert & Braking, which can apply brakes if the system determines the vehicle has unintentionally left the roadway
I stated this earlier, but it bear repeating, Bendix safety technologies complement safe driving practices. No commercial vehicle safety technology replaces a skilled, alert driver exercising safe driving techniques and proactive, comprehensive driver training. Responsibility for the safe operation of the vehicle remains with the driver at all times.
In any one of these situations – or countless others – why wouldn’t you want your drivers and their assistance technologies equipped with the most effective and reliable brakes? You’ve invested a lot in your driving team, your fleet, and your advanced safety technologies – and air disc brakes are the best choice to protect them all.
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