Winter is the time of year when even an impressive driving experience suddenly ceases to matter. The scenario is familiar to many: you drive onto a snowy road, the brake lights ahead light up, your foot reflexively presses the brake - and instead of a confident stop, the pedal starts to vibrate wildly, and the rear bumper of the car in front approaches frighteningly quickly. In the worst case, the oncoming lane looms somewhere to the side.
At this moment, a logical thought flashes through your head: "How so? ABS is supposed to help, but the car doesn't seem to brake at all."
Because of such situations, the anti-lock braking system has many opponents. It is especially criticized by old-school drivers who have switched to modern cars from classic "Zhiguli" cars, where there was no electronics. Their argument is simple: "I would have braked more efficiently myself, and this system only interferes." And the most unpleasant thing is that in loose snow or deep slush there is indeed some truth in these words.
To understand where this feeling of "betrayal" comes from, it is enough to analyze the physics of the process. Why on dry asphalt ABS is almost always an ally of the driver, and on loose snow the system is able to increase the braking distance by one and a half times? And most importantly, what to do about it: reach for the fuse box or still change the settings in your own head?
The "bulldozer" effect: what electronics take away
It is worth starting with the basic principle of braking a car without an anti-lock braking system - in a skid.
When you press the brake sharply, the wheels lock completely and stop rotating.
- On asphalt, this is bad. The rubber begins to slip, heat up and actually "float" on the surface. The braking distance increases, and the tires wear out at a catastrophic rate.
- In loose snow, sand or gravel, the situation is the opposite. The locked wheel works like a bulldozer blade: it rakes a ridge of snow or soil in front of it - the very "snow wedge". This shaft creates powerful physical resistance and helps the car stop noticeably faster.
ABS deprives the driver of this very effect. As soon as the sensors detect the start of locking, the system reduces the pressure in the brake circuit for fractions of a second. The wheel starts to rotate again - and simply rolls over the resulting snow ridge, which could have braked it.
As a result, the car does not dig into the surface, but slides along its surface. That is why on snow slush or loose snow, the braking distance with ABS on is almost always longer. Yes, it sounds unpleasant, but it's pure physics.
The main exchange: meters for life
A logical question arises: if the engineers know about this (and they, of course, know), why wasn't the anti-lock removed and each car equipped with a shutdown button?
The answer is simple: a conscious choice was made. Braking distance was exchanged for handling.
The physics of a school course explains everything quite harshly. Sliding friction is uncontrollable.
- Locked wheels mean one thing: the car flies strictly where inertia pushed it at the moment of braking. Turning the steering wheel is useless - the car will still go straight, whether it's a pole, a truck or a ditch.
- Rotating wheels maintain traction with the road surface. This means that the car responds to the steering wheel.
The logic of ABS is extremely pragmatic: "Yes, we will stop a few meters further. But during these meters, the driver will be able to drive around the obstacle and survive, instead of flying into it with fully locked wheels."
The anti-lock braking system is not designed for braking distance records. Its task is to make it possible to stop where the driver needs to, and not where inertia carried the car.
How to brake correctly: goodbye, USSR driving school
On old cars without electronics, they taught a simple technique: to press the brake intermittently, imitating the operation of ABS with your foot. On modern cars, this approach turns into a mistake.
When the driver starts to frequently release and press the pedal again, the electronic unit perceives this as a cancellation of braking and adjusts its operation.
The correct algorithm is different:
- Sudden pressure. In an emergency, the brake pedal must be pressed sharply and all the way.
- Do not release. Even if the pedal vibrates, hits your foot and there is a frightening crackling sound. This is not a breakdown - this is how the ABS pump works, making up to twenty cycles per second.
- Press and steer. The gaze should not get stuck on the bumper of the car in front. You need to work the steering wheel. It is ABS that allows you to perform an obstacle avoidance maneuver - the very "lane change" - right during intensive braking.
Exceptions to the rules: when ABS really interferes
There are situations where the "bulldozer" effect is more important than handling.
- Off-road. On steep descents on clay or loose soil, SUVs often deprive ABS of power by removing the fuse. It is critical there to rake the soil in front of the wheels, otherwise the system may "release" the brakes, and the car will simply roll down without resistance.
- Motorsport. In rallying, anti-lock is also used, but with completely different settings that allow significant wheel locking for grip on the ground.
However, on public roads, even in heavy snowfall, the ability to drive around a suddenly appearing pedestrian or obstacle is more important than an additional 0.5 meters of braking distance.
Don't be afraid of crackling
Winter crackling under the pedal is normal. It's the sound of struggle: physics tries to send the car by inertia, and electronics tries to maintain control and save the driver.
Yes, on loose snow, the distance should be increased at least twice and remember that you no longer have a "bulldozer" effect. But the main thing remains - control over the car. Which means a chance to remain a pilot, not a passenger of an uncontrollable projectile.