Your trucks need EBS and ESC: Here's why
This year’s National Truck Accident Research Centre (NTARC) Major Accident Investigation 2021 Report has just been released, and its findings are sobering.
While there has been improvement in some areas, there are still too many crashes and incidents in Australia every year. These include single and multiple vehicle crashes.
Inappropriate speed and driver error accounted for more than half (54.5%) of all large loss crashes, while inadequate following distance accounted for nearly one in ten (9.3%). Regardless of which driver is at fault – and in nearly eight out of ten (78.3%) fatal crashes involving a truck and a car, the car driver was at fault.
Technology plays a significant role in making our roads and the vehicles that use them safer. While autonomous trucks remain some way off, fleets can deploy systems to alert and assist truck drivers about the road conditions and hazards they face.
Among these are Electronic Braking System (EBS) and Electronic Stability Control (ESC) technologies. Without impacting the driver’s autonomy, they can play a critical role in avoiding collisions and rollovers.
EBS: braking faster and better
EBS and ESC are complementary technologies, with ESC systems relying on EBS as a foundational component.
Braking systems in the majority of heavy vehicles use air in two ways. First, as both the control signal between the pedal and the rest of the braking system. Second, as the source of energy to apply the physical braking components.
The first – the pneumatic control signal – results in a significant lag in brakes activating, particularly on the rear trailers in longer combinations.
“Electronic braking systems augment the pneumatic control signals that activate brakes,” says NTARC report author and NTI Transport and Logistics Risk Engineer Adam Gibson.
“They activate all of the brakes on a heavy vehicle combination at once so they can respond near instantly.
“They’re particularly valuable in Australia, as we are the home of the largest combinations in the world. Although the technology was developed in Europe, it’s actually been of the greatest benefit to us here.”
ESC: keeping combos right-side up
ESC systems work alongside EBSes to avoid rollovers. Sensors track wheel speed and lateral acceleration or cornering force. Where the system detects a truck entering a corner with too much speed or force it can very lightly apply some brakes to add drag at each wheel, taking up any free-play in the system and keeping the combination stable.
The system then monitors wheel speed. If the speed of a wheel drops to zero or is rapidly dropping towards zero, it’s likely to be off the ground.
“At that moment, it knows you’re tantalisingly close to laying it on its side,” says Adam. “That’s when it applies more brakes, particularly on the other (loaded) side of the combination, because, obviously, the ones in the air aren’t doing anything.”
One of the challenges is that most rollovers occur from the back to the front. The last trailer in a combination isn’t held down by a trailer behind it, so it can tip – or start to tip – without the driver feeling a thing.
“The system can save you,” says Adam, “because the brakes can react faster and in situations the driver can’t detect.”
There is a perverse risk, however: that drivers can become too reliant on the systems, especially for managing cornering speed. But no technology, no matter how sophisticated, is foolproof. Driver vigilance and skill are always required.
Alert drivers are more important than driver alerts
That’s why driver’s concerns about such systems taking away their control and autonomy are misplaced. Complacency can be as much a killer as inattention or speed. For the best safety outcomes, trucks need skilled drivers more than they need automated and electronic systems.
Because the most important safety system in any truck is the one that’s located between the seat and the steering wheel.