Calculation of the length of the braking distance of the car
Not all drivers know that, depending on
braking conditions from a speed of 60 km/h, the stopping distance can be
both 25 and 150 meters. What determines its length?
Vehicle Ability
reduce the speed to the required value (up to a stop), while
while maintaining stability and control, depends on its braking properties.
In the theory of the car, a number of indicators are used to evaluate the braking properties:
maximum deceleration, braking distances, brake response time
mechanisms, range and algorithm for changing braking forces, drop in efficiency
due to prolonged operation (heating).
These indicators are determined by the design of systems and mechanisms of the car.
The main system is the brake, or more precisely, the brakes. Yes, in fact
The car has three braking systems. The first - working (or main) -
actuated by the brake pedal. The second - parking - is used
to keep the car in the parking lot, and in case of failure of the main system
helps to slow down a moving vehicle. The third, auxiliary, is the engine.
After all, when you take your foot off the gas pedal, the car goes into braking mode.
engine.
The next "influential" elements are regulation and distribution systems
brake forces, suspension (shock absorbers + springs) and tires.
Stopping distance is the distance traveled by the vehicle from the moment
depress the brake pedal until it comes to a complete stop. What does it depend on? Naturally,
from actuation time brake system, as well as on the initial speed
movement and the maximum deceleration that the car can develop.
Pay attention to a number of points. The first term says that
after pressing the brake pedal, the car will not slow down immediately,
but after some time. For vehicles with hydraulic brakes (all
cars and part of trucks) this time is 0.1-0.3 s, and for cars
with pneumatic drive (trucks of medium and heavy duty) – 0,3-0,5
With. Some more time (0.36-0.54 s) will be needed for an increase in the braking
effort from zero to maximum. The second term includes the speed "squared".
This means that if the speed is doubled, the stopping distance will increase.
four times!
Although vehicle deceleration depends on the design and function of the brake
mechanisms, it is also affected by the condition of tires and shock absorbers (with faulty
shock absorbers, the wheel cannot maintain constant contact on bumps
with the road).
Grip coefficient depends on tires and condition
road surface. The amount of deceleration is affected by the type of tire (winter or
summer), width and tread pattern, degree of wear. During testing
different tires, it was found that the braking distance of the same cars
with tires different manufacturers may vary by several meters. About
changing the braking distance depending on the road surface and talking
nothing, just compare dry asphalt and ice.
In addition to the braking distance, there is the concept stopping way. This is the length
area, which pass the car from the moment the driver detects an obstacle
to a complete stop.
In other words, the driver, seeing any obstacle, must realize
danger, decide to stop or slow down, reschedule
foot from the gas pedal to the brake pedal and press it. It takes from 0.3
up to 1.7 s! The first number is the indicator of athletes, the second - inexperienced
driver, in some situations it can be even more - for example,
the driver got scared, got confused in the pedals, etc.
In order for the car to stop in a timely manner, you need to perform
the following rules.
1 The driving speed should be selected in such a way
in such a way that it is always possible to stop
in front of an unexpected obstacle. In other words, dangerous
the speed itself, but its inconsistency with the real conditions of movement.
Do not forget that doubling the speed will result in four times
increase in stopping distance.
2 Distance to the vehicle in front
must be able to stop if emergency braking
"leader". Pay attention to which car is ahead:
how newer model car, the shorter it can be
braking distances. Cars with ABS tend to stop
faster than without it. Old textbooks recommended keeping
a distance in meters equal to half the speed in km/h.
3
Technical condition car. Regularly
inspect the brake system (pad thickness, condition
hoses) and correct any malfunctions in a timely manner (increased
stopping distance, pull to the side during braking, etc.). Not
remember that after a series of intense braking performance
system is reduced due to the heating of the discs and pads.
4 Attention! Even on racing car
you may not have time to stop if you do not pay attention to
what is happening on the road. Can't get out of control
car, talk mobile phone etc. Watching
behind what is happening through the windows of the car in front, you can
get time to make a decision. And toned rear
windshield of your car, you increase the risk of being hit from behind.
5 Maneuvering. Don't Change Directly
in front of trucks and buses. If you have to
brake hard, the driver of the car with less efficiency
braking will stop in the trunk of your car. Besides
you may be accused of violating paragraph 10.1 of the traffic rules, which states,
that before moving, rebuilding and any change
direction of travel, the driver must ensure that this is not
creates obstacles or dangers to other road users.
Even if the truck driver is found guilty, you
it won't be much easier, as the car will have to be repaired.
Viktorious. Krivoy Rog
Let us compare a collision with a fixed obstacle with a fall with a certain
height. The formulas have been known since school (mgh = mV^2/2, potential
energy at the end of the fall is completely converted into kinetic energy). That.,
you can make sure that a sharp impact on an obstacle at a speed of 30 km / h
equivalent to a fall from a height of 3 meters, at a speed of 60 km / h - from 14
meters, 90 km / h - 31 meters, 120 km / h - 55 meters.
14 meters is
height 5-6 floors. That is, a sharp blow at a speed of 60 km / h is equivalent to
fall from the 6th floor. Unpleasant, but very good chance survive,
especially if you take into account airbags, etc…
31
meters - this is already more than the height of a nine-story building. I don't think I need to explain
that the chances of surviving such a collision are very small ... There are even pillows
security is unlikely to help (and you would jump from the roof of a nine-story building,
laying down two inflatable pillows?). Not to mention falling from
55 meters high (here, as they say, no chance).
It's on
the case of a sharp collision with an immovable obstacle. Now consider,
if the driver notices an obstacle. The reaction time is usually
say, 1 second (really from 0.5 to 1 second, correct me if I'm wrong).
During this time, the car will travel at a speed of 60 km / h - 17 meters, at
speed of 90 km/h - 25 meters, at a speed of 120 km/h - 33 meters.
The braking distance on a normal road is at a speed of 60 km / h -
23-30 meters, 90 km/h - 50-60 meters, 120 km/h - over 90 meters
(http://www.autocentre.ua/.
What
we have? In order to have time to completely slow down from a speed of 120 km / h, you need to
see an obstacle from a distance of more than 120 meters! And finally a question
to a driver who thinks it's okay to drive at 120 km/h:
Are you really SURE that under any circumstances, eg. at night,
in the light of oncoming headlights, you can see ANY obstacle (sharply
an animal that jumped onto the road, a car on the side of the road with the
dimensions, etc.) on your way from a distance of 120 meters? Issue price
- life…
The diagrams are built on the basis of the data " Automobile directory Bosch,
ed. 1999
help with speed Daewoo car sens. braking distance to collision 24.1m dry asphalt
how long will it take for an emergency stop of an onboard Gazelle car moving at a speed of 20 km / h on wet asphalt concrete (using average data), including the reaction time of the driver and the response time of the brake actuator?
I found a program in the field of auto technology and auto commodity science, developed by the staff of the PALE expert research laboratory. These programs will help you quickly and accurately determine the speed of vehicles (Vehicles) on the trail of their braking, calculate the stopping distance of the vehicle, their distance from a given point at various points in time, determine the permissible speed of the vehicle according to visibility conditions, traffic on the curvature of the carriageway, solve tasks of analyzing road accidents by graphical and graph-analytical methods, to determine residual value Vehicle. http://www.mobitech.net.ua/soft/7834 …-
16-light.html
hello, please tell me the speed of the car with a stopping distance of 16 meters and a mass of 2235 kg
I do not understand anything
I was standing on the side of the road, I was hit by a car - it flew off 150m, is it possible to roughly calculate the speed of this car.
Best regards, Sergei
Please describe all the laws in the decision. The car is braked on the mountain slope with a slope of no more than 0.9 (tga=0.9). what is the braking distance of this car on a horizontal surface at a speed of 45 km.h.
The accident happened not on deer, but on a car. I was driving in an empty lane. Night. A convoy of transport (not deer) is coming to the meeting. Suddenly, at a distance of about 200 m from me, a Schumacher on a KIA flies out of the column of oncoming traffic and rushes towards me. Thought it would turn. And hell there. There were 30-40 meters left, I turned off the speed, and at 10-15 m I realized - p..c, pressed the brake. Hit. You are in the hospital. carried on oncoming lane. Got to the hospital. Then the investigator pinned down and said that I was to blame, because I didn’t slow down in time and didn’t stop.
Tell me what to do.
I am clarifying. The accident happened not on deer, but on a car. I was driving in an empty lane. Night. A convoy of transport (not deer) is coming to the meeting. Suddenly, at a distance of about 200 m from me, a Schumacher on a KIA flies out of the column of oncoming traffic and rushes towards me. Thought it would turn. And hell there. There were 30-40 meters left, I turned off the speed, and at 10-15 m I realized - p..c, pressed the brake. Hit. Carried out into the opposite lane. Got to the hospital. Then the investigator pinned down and said that I was to blame, because I didn’t slow down in time and didn’t stop.
Tell me what to do.
help determine the speed of the Daewoo Leganza. braking distance before collision 11.3 meters asphalt pavement dry
Help determine the speed of the viburnum car with abs. From the moment of collision to a complete stop, 5.2 m. brake track
The question is interesting. Who has the longest stopping distance?
Case 1: Passenger car without ABS or unloaded KAMAZ.
Case 2: Passenger car without ABS or loaded KAMAZ.
here the question is this. Weight truck many times more than the mass of a passenger car, but the coefficient of adhesion of a truck is many times greater. What decides anyway?
PLEASE DISCOVER THE SPEED OF THE AUTO VAZ-2106 IF ONLY THE BRAKING DISTANCE OF 14 METERS IS KNOWN. ASPHALT IS DRY.
Please help determine the speed of Subaru Forester auto weight 1440kg stopping distance 49 meters! On dry pavement!
Please help me determine the speed of a Vaz2109 car that was driving downhill somewhere with a 7-8 percent slope .... The braking path is 15.5 meters ...
Help people plz. What was the speed of the VAZ-2114 car if the braking distance was 72 meters. (pads are new)
http://lg.vgorode.ua/news/76504/ Hello, I'm a rider of the nine. found me guilty. The driver of the Mitsubishi Lancer did not even slow down before the accident. i.e. there is no braking distance. I was thrown 38 meters away from the Sudar point. the motor block is broken. how to approximately calculate for yourself the speed of mitubishi. Mitsubishi driver said that he was driving 60 km per hour. thank you in advance
I will send a manual for calculating the braking distance, collision, collision with pedestrians to everyone who writes to the mail sneg-chudodogramblerpointkar
and why my braking distance from 120km/h does not exceed 60 meters?
Here, many people ask to calculate the speed from the stopping distance, mass, etc. but this is not enough in cases where the collision did occur!
In this case, it is necessary to take into account the damage to the car, because if there were no obstacles on the way, then the braking distance, for sure, would be much longer! How stronger damage- the more you need to add to the length of the tire track. Here's how to determine how much to add. After all, the design and rigidity of the car are different!
Very important. Shevolle Avita slowed down 25 meters on DRY asphalt, having the opportunity to bypass KAMAZ turning to the gas station on the RIGHT. As a result - a powerful blow to the KAMAZ tank. Braking EMERGENCY - a trace from the brakes - like black paint on asphalt. The cops arrived bought and say that the speed was 40 km and KAMAZ is to blame for not giving way. KAPETS what to do What speed. PRISON shines. help me good people ...... I have not seen a Chevrolet .... she wasn't on the left...
I have such a situation ... one-way traffic two lanes I move along right side on the left side, the car makes a maneuver without turn signals and did not make sure it was safe before turning. my braking distance was 13-15 meters.
http://in-drive.ru
Any motorist knows that often we are separated from an accident in just a fraction of a second. A car moving at a certain speed cannot freeze in place after depressing the brake pedal, even if you have Continental tires, which traditionally rank high in the ratings, and brake pads with high brake pressure.
After pressing the brake, the car still overcomes a certain distance, which is called the brake or stopping way. So stopping distance is the distance traveled vehicle from the moment the brake system is applied to a complete stop. The driver must at least approximately be able to calculate the stopping distance, otherwise one of the basic rules of safe movement will not be observed:
- the stopping distance must be less than the distance to the obstacle.
Well, here such an ability as the driver’s reaction speed comes into play - the sooner he notices an obstacle and presses the pedal, the earlier car will stop.
The length of the braking distance depends on such factors:
- movement speed;
- quality and type of road surface - wet or dry asphalt, ice, snow;
- the condition of the tires and braking system of the vehicle.
Please note that such a parameter as the weight of the car does not affect the length of the braking distance.
The braking method is also of great importance:
- sharp pressing to the stop leads to uncontrolled skidding;
- gradual increase in pressure - used in a calm environment and with good visibility, in emergency situations does not apply;
- intermittent pressing - the driver presses the pedal several times to the stop, the car may lose control, but stops quickly enough;
- step pressing - works on the same principle ABS system, the driver completely locks and releases the wheels without losing contact with the pedal.
There are several formulas that determine the length of the stopping distance, and we will apply them for different conditions.
dry asphalt
The braking distance is determined by a simple formula:
From the course of physics, we remember that μ is the coefficient of friction, g is the acceleration of free fall, and v is the speed of the car in meters per second.
Imagine the situation: we are driving a VAZ-2101 at a speed of 60 km / h. At 60-70 meters we see a pensioner who, forgetting about any safety rules, rushed across the road after a minibus.
We substitute the data in the formula:
- 60 km/h = 16.7 m/s;
- the coefficient of friction for dry asphalt and rubber is 0.5-0.8 (usually 0.7 is taken);
- g = 9.8 m/s.
We get the result - 20.25 meters.
It is clear that such a value can only be for ideal conditions: good quality tires and brakes everything is fine, you braked with one sharp press and all the wheels, while not going into a skid and not losing control.
You can double-check the result using another formula:
S \u003d Ke * V * V / (254 * Fc) (Ke - braking coefficient, for passenger cars it equals one; Фс - adhesion coefficient with coating - 0.7 for asphalt).
IN this formula put the speed in kilometers per hour.
We get:
- (1*60*60)/(254*0.7) = 20.25 meters.
Thus, the length of the braking distance on dry pavement for passenger cars moving at a speed of 60 km / h, under ideal conditions, is at least 20 meters. And that's with hard braking.
Wet asphalt, ice, packed snow
Knowing the adhesion coefficients with pavement, you can easily determine the braking distance under various conditions.
Odds:
- 0.7 - dry asphalt;
- 0.4 - wet asphalt;
- 0.2 - packed snow;
- 0.1 - ice.
Substituting these data into the formulas, we obtain the following values for the length of the stopping distance when braking at 60 km/h:
- 35.4 meters on wet pavement;
- 70.8 - on packed snow;
- 141.6 - on ice.
That is, on ice, the length of the braking distance increases by 7 times. By the way, on our website Vodi.su there are articles on how to properly drive a car and brake in winter time. Also, safety during this period depends on right choice winter tires.
If you are not a fan of formulas, then on the net you can find simple calculators stopping distance, whose algorithms are based on these formulas.
Stopping distance with ABS
The main task of ABS is to prevent the car from going into an uncontrolled skid. The principle of operation of this system is similar to the principle of stepped braking - the wheels are not completely blocked and thus the driver retains the ability to drive the car.
Numerous tests show that with ABS brake shorter way to:
- dry asphalt;
- wet asphalt;
- rolled gravel;
- on the plastic sheet.
On snow, ice, or muddy soil and clay, braking performance with ABS is somewhat reduced. But at the same time, the driver manages to maintain control. It is also worth noting that the length of the braking distance largely depends on the settings of the ABS and the presence of EBD (brake force distribution system).
In short, the fact that you have ABS does not give you an advantage in the winter. The length of the braking distance can be 15-30 meters longer, but then you do not lose control of the car and it does not deviate from its route. And on the ice, this fact means a lot.
Motorcycle stopping distance
Learning how to properly brake or slow down on a motorcycle is not an easy task. You can brake front, rear or both wheels at the same time, engine braking or skidding is also used. If you brake incorrectly high speed you can very easily lose your balance.
The braking distance for a motorcycle is also calculated using the above formulas and is for 60 km / h:
- dry asphalt - 23-32 meters;
- wet - 35-47;
- snow, mud - 70-94;
- black ice - 94-128 meters.
The second digit is the skid braking distance.
Any driver or motorcyclist should know the approximate stopping distance of their vehicle at different speeds. When registering an accident, traffic police officers can determine the speed at which the car was moving along the length of the skid.
In addition to the conclusion in the name, in fact, the movement implies a stop. You slow down at a traffic light pedestrian crossing, in front of another car and the like many times per trip. Sometimes (usually more often than you would like) you have to stop very quickly and abruptly. There are 2 terms to be distinguished in this regard: stopping distance and stopping distance. They mean different things, although they are connected by a common purpose: to show the driver that the laws of inertia apply to any car.
What is the difference
The braking distance for each car is a static indicator. It is measured by engineers on tests, indicated in extended specifications. Of course, we are still talking about ideal conditions. Such indicators will not take into account wet asphalt, worn pads and. Therefore, you should not take these numbers as something magical that will make your car slow down equally on dry new asphalt and on wet ice. You just need to focus on them, nothing more.
Much more significant indicator for the driver (and much more subjective, no matter how paradoxical it may sound) there will be a stopping path. What is meant by stopping distance can only be measured once. Most likely, each time the numbers will be different, this is determined by the very essence of the indicator. So, this is the distance that the car travels from the moment the driver notices the obstacle to the moment it comes to a complete stop. That is, this indicator depends on the speed of your reaction, on your concentration on road conditions, on the force with which you press on the brake pedal ... Naturally, all this is very individual. You can say that the numbers should not differ too much, and we would agree with you if it were not for one “but”: the time between “notice” and “realize” depends very much on your condition. An outside observer can at least somehow appreciate it, but you yourself are not capable of it. In particular, this is why it is forbidden to drive drunk. Your reaction slows down, but you yourself do not realize it; therefore, a drunk driver poses a huge danger to all road users, including himself.
How to count
Formulas for calculating the stopping distance, respectively, do not exist. Our mathematical apparatus is not capable of processing such a number of variables. So please don't take your eyes off the road while driving.
The braking distance is often identified with the length of the brake track. Although these indicators do not mean the same thing, they follow one from the other. Therefore, we will not deviate from the generally accepted practice. In this sense, the stopping distance is widely used in parsing traffic situations; for example, knowing the mass of the car and measuring the stopping distance, you can determine the speed at which the car was moving. If we talk about the finished formula, then this is how it looks:
V a - in fact, the speed that we need to calculate;
t c - time of braking amplification;
j - set braking time (taken from the table);
S u - the length of the brake track.
Note that the units of measurement in this equation are seconds and meters. Accordingly, you will receive the answer in meters per second; we warn not to confuse you. At first glance, the formula is not so complicated. However, the calculations can confuse you due to the rather large number of parameters and their opacity. For example, the braking boost time somehow doesn't intuitively appear in your head when you look at the trail. Determining the speed along the stopping distance still remains the lot of experts. Now imagine that in addition to this, you need to take into account a dozen more parameters related to you and your condition. Represented? This is difficult for a person unprepared for mathematics, physics and ballistics, so we will also leave the calculations to the experts. They need to do something.
And then what
It is possible to calculate the braking distance of the car, but we believe that this is meaningless. It is somehow hard to imagine that a driver, especially an inexperienced one, at the moment when you need to make a decision, begins to substitute numbers in the formula. There are averages, and you should focus on them. Let them be approximate, but they can tell you the order of the numbers, the "fork" of values. There are tables of stopping distances of a car depending on its class, because, of course, a heavy SUV slows down in a completely different way than a minicar. These tables are compiled for a speed of 60 km/h. But be careful, the proportion for the calculation is insidious, it multiplies the values by the square of the "delta", that is, if the speed is increased by 2 times, the braking distance will increase by 4 times!
There are certain standards for the weight of a car of a certain class. It is unlikely that, say, a huge pickup truck will weigh less than one and a half tons (we would put, in fact, 2 tons). But a sports car or supercar, the body of which is made almost entirely of carbon fiber or some other hyper-innovative material, is a completely different matter. It does not fit into any table, and it does not belong there. That is why the values in the table are averaged and they are given for owners of production cars.
These values, as we have already written, should not be taken by you as the ultimate truth. These are ideal figures, only professional racers on completely new cars can repeat them. This table can show the stopping distance for wet road, but we all know that "wet" is not the same. Downpour or rain? Plus on the street, zero or minus? Day or night? So the table is not a panacea. Yes, it's useful for letting you know how far your car will roughly travel after you've pressed , but no more. Anyway, you need to be careful and keep your distance on the road.
No calculator needed
To somehow calculate the stopping distance of your car, you need knowledge, perseverance and a lot of data. So this, as we said above, is not very useful. Instead, it is better to take steps to reduce this value, even if you do not know it to the nearest centimeter. Regularly check the condition of the brake system, top up brake fluid change pads. And carefully look behind the road, it can save not only yours, but also someone else's life.
However, don't overdo it. Of course, but if you figured out that your stopping distance will be approximately, say, 20 meters, this does not mean that you need to keep exactly this distance between your cars. Be a sane person. The car in front is moving at a speed comparable to yours, and it also has mass, so it won't be able to brake instantly. Therefore, a few meters between you will be enough.
Another important point for you: is your ABS machine? If yes, then this system will protect you from locked wheels during any braking, especially during hard braking. So, you will not be carried into an uncontrolled skid. If this system is not on your car, then do not press the pedal with all your might. Raise your leg periodically, just a little. This will loosen the pressure of the brake pads, allow the wheel to spend at least a small part of the braking inertia on scrolling, and again, will not let it go off track.
In general, our recommendations are banal to the point of impossibility: monitor the state of your car's systems, watch the road, do not drive drunk or sleepy, and remember that the road is dangerous. Don't relax and it will save your life.
It may happen that the integrity of the car body and the safety of its passengers will depend on the length of the braking distance. A car at speed simply cannot freeze abruptly after pressing the brake, even if it has high-quality tires and efficient system braking. After the brake pedal is pressed, the car in any case overcomes a certain distance, and this distance is called the braking distance.
The driver must constantly calculate the length of the braking distance in accordance with one of the rules for traffic safety, which says that the braking distance must be less than the distance to the obstacle.
In this situation, it all depends on the reaction and skill of the driver, the sooner he presses the brake and correctly calculates the length of the braking distance, the sooner, and more successful than a car slow down.
Braking distance of the car at a speed of 60 km / h
Deformation of the body in a collision at a speed of 60 km / h
Stopping distance also depends not only on the driver, but also on other related factors: on the quality of the road, speed, weather conditions, the state of the brake system, the design of the brake system, car tires, and many others.
note that weight passenger car does not affect the length of the braking distance. This is due to the fact that the weight of the car increases the inertia of the car when braking, while preventing braking, but increases the grip of the tires due to the increased mass of the car.
These physical properties compensate each other, while practically not affecting the length of the braking distance.
The speed of braking directly depends on the method of braking. sharp brake to the stop, will cause the machine to skid or skid (if the machine is not equipped with an ABS system).
Gradual pressing on the pedal applied when on the road good visibility and calm environment, it is not suitable for emergency situations. When pressed intermittently you can lose control, but then stop quickly. Also possible stepped pressing(similar in effect to ABS system).
There are special formulas that allow you to determine the length of the braking distance. We will try to calculate the formula for different conditions, depending on the type of road surface.
Formula for determining the stopping distance
Braking distance on dry pavement
We remember the lessons of physics, where ? is the coefficient of friction, g is the free fall acceleration, and v is the speed of the vehicle in meters per second.
The situation is as follows: the driver is driving car Lada whose speed is 60 km/h. Literally 70 meters away is an elderly woman who, forgetting about safety rules, hastily catches up with fixed-route taxi(standard situation for Russia).
Let's use this very formula: 60 km/h = 16.7 m/sec. Dry asphalt has a friction coefficient of 0.7, g - 9.8 m/s. In fact, depending on the composition of the asphalt, it is from 0.5 to 0.8, but still take the average value.
The result obtained by the formula is 20.25 meters. Naturally, this value is only relevant for ideal conditions when the machine is equipped with quality rubber and brake pads, the brake system is in good condition, when braking you do not skid and do not lose control, from many other idealized factors that are not found in nature.
Also, to double-check the result, there is one more braking distance formula:
S = Ke * V * V / (254 * Fs), where Ke is the braking coefficient, for passenger cars it is equal to one; Фс - coefficient of adhesion with a coating of 0.7 (for asphalt).
Substitute the speed of the vehicle in km/h.
It turns out that the braking distance is 20 meters for a speed of 60 km / h, (for ideal conditions), if the braking is sharp and without skidding.
Braking distance on the surface: snow, ice, wet asphalt
BMW cars on trial
The friction coefficient helps to indicate the length of the stopping distance at different road conditions. Odds for different road surfaces:
- Dry asphalt - 0.7
- Wet asphalt - 0.4
- Rolled snow - 0.2
Let's try to substitute these values into the formulas, and find the values of the braking distance for the road surface at different times of the year and under different weather conditions:
- Wet asphalt - 35.4 meters
- Rolled snow - 70.8 meters
- Ice - 141.6 meters
It turns out that on ice the length of the braking distance is practically seven times higher relative to dry asphalt (as well as the substituted factor). The length of the braking distance is affected by the quality of winter tires, physical properties.
Testing has shown that with the ABS system, the stopping distance is significantly reduced, but still, on ice and snow, ABS does not affect, but rather worsens braking performance when compared with a braking system without ABS. However, in ABS, to a large extent, everything depends on the settings and the presence of a brake force distribution system (EBD).
The advantage of ABS in winter- full control over the control of the car, which minimizes the occurrence of uncontrolled skidding when braking. The principle of operation of ABS is similar to the performance of stepped braking on vehicles without ABS.
The ABS system reduces the stopping distance by: dry and wet asphalt, rolled gravel, road marking.
On ice and packed snow, the use of ABS increases the braking distance by 15 - 30 meters, but allows you to maintain control over the car, without taking the car into a skid. This fact should be taken into account.
How to brake on a motorcycle?
Correctly braking on a motorcycle is a rather difficult task. Can be braked rear wheel, front, or two, skid or engine. At improper braking on high speeds you can lose your balance. In order to calculate the braking distance of a motorcycle at 60 km / h, the data is also substituted into the formula. Considering at the same time a different braking coefficient and coefficient of friction.
Braking distance of motorcycles
- Dry asphalt: 23 - 33 meters
- Wet asphalt: 35 - 46 meters
- Mud and snow: 70 - 95 meters
- Ice: 95 - 128 meters
The second indicator is the braking distance when the motorcycle is skidding.
Any vehicle owner should know and be able to calculate the length of the braking distance, and it is better to do this visually.
It should be remembered that in the event of a traffic accident along the length of the skid, which will remain on the road surface, you can determine the speed of the vehicle before colliding with an obstacle, which may indicate an excess allowable speed driver and make him the culprit of the accident.
Any motorist knows that often we are separated from an accident in just a fraction of a second. A car moving at a certain speed can't stop dead in its tracks after depressing the brake pedal, even if you have traditionally high-ranking Continental tires and brake pads with a high brake pressure ratio.
After pressing the brake, the car still overcomes a certain distance, which is called the braking or stopping distance. Thus, the stopping distance is the distance that the vehicle travels from the moment the brake system is activated to a complete stop. The driver must at least approximately be able to calculate the stopping distance, otherwise one of the basic rules of safe movement will not be observed:
- the stopping distance must be less than the distance to the obstacle.
Well, here such an ability as the speed of the driver's reaction comes into play - the sooner he notices the obstacle and presses the pedal, the sooner the car will stop.
The length of the braking distance depends on such factors:
- movement speed;
- quality and type of road surface - wet or dry asphalt, ice, snow;
- the condition of the tires and braking system of the vehicle.
Please note that such a parameter as the weight of the car does not affect the length of the braking distance.
The braking method is also of great importance:
- sharp pressing to the stop leads to uncontrolled skidding;
- gradual increase in pressure - used in a calm environment and with good visibility, not used in emergency situations;
- intermittent pressing - the driver presses the pedal several times to the stop, the car may lose control, but stops quickly enough;
- stepped pressing - works according to the same principle, the driver completely blocks and releases the wheels without losing contact with the pedal.
There are several formulas that determine the length of the stopping distance, and we will apply them for different conditions.
dry asphalt
The braking distance is determined by a simple formula:
From the course of physics, we remember that μ is the coefficient of friction, g is the acceleration of free fall, and v is the speed of the car in meters per second.
Imagine the situation: we are driving a VAZ-2101 at a speed of 60 km / h. At 60-70 meters we see a pensioner who, forgetting about any safety rules, rushed across the road after a minibus.
We substitute the data in the formula:
- 60 km/h = 16.7 m/s;
- the coefficient of friction for dry asphalt and rubber is 0.5-0.8 (usually 0.7 is taken);
- g = 9.8 m/s.
We get the result - 20.25 meters.
It is clear that such a value can only be for ideal conditions: good quality rubber and everything is fine with the brakes, you braked with one sharp press and all the wheels, while not going into a skid and not losing control.
You can double-check the result using another formula:
S \u003d Ke * V * V / (254 * Fc) (Ke is the braking coefficient, for passenger cars it is equal to one; Fs is the coefficient of adhesion with the coating - 0.7 for asphalt).
Substitute the speed in kilometers per hour into this formula.
We get:
- (1*60*60)/(254*0.7) = 20.25 meters.
Thus, the length of the braking distance on dry pavement for passenger cars moving at a speed of 60 km / h, under ideal conditions, is at least 20 meters. And that's with hard braking.
Wet asphalt, ice, rolled snow
Knowing the coefficients of adhesion to the road surface, you can easily determine the length of the braking distance under various conditions.
Odds:
- 0.7 - dry asphalt;
- 0.4 - wet asphalt;
- 0.2 - packed snow;
- 0.1 - ice.
Substituting these data into the formulas, we obtain the following values for the length of the stopping distance when braking at 60 km/h:
- 35.4 meters on wet pavement;
- 70.8 - on packed snow;
- 141.6 - on ice.
That is, on ice, the length of the braking distance increases by 7 times. By the way, on our website there are articles about that, and. Also, safety during this period depends on the correct choice of winter tires.
If you are not a fan of formulas, then on the net you can find simple stopping distance calculators, the algorithms of which are built on these formulas.
Stopping distance with ABS
The main task of ABS is to prevent the car from going into an uncontrolled skid. The principle of operation of this system is similar to the principle of stepped braking - the wheels are not completely blocked and thus the driver retains the ability to drive the car.
Numerous tests show that braking distances are shorter with ABS by:
- dry asphalt;
- wet asphalt;
- rolled gravel;
- on the plastic sheet.
On snow, ice, or muddy soil and clay, braking performance with ABS is somewhat reduced. But at the same time, the driver manages to maintain control. It is also worth noting that the length of the braking distance largely depends on the settings of the ABS and the presence of EBD (brake force distribution system).
In short, the fact that you have ABS does not give you an advantage in the winter. The length of the braking distance can be 15-30 meters longer, but then you do not lose control of the car and it does not deviate from its route. And on the ice, this fact means a lot.
Motorcycle stopping distance
Learning how to properly brake or slow down on a motorcycle is not an easy task. You can brake front, rear or both wheels at the same time, engine braking or skidding is also used. If you slow down incorrectly at high speed, you can very easily lose balance.
The braking distance for a motorcycle is also calculated using the above formulas and is for 60 km / h:
- dry asphalt - 23-32 meters;
- wet - 35-47;
- snow, mud - 70-94;
- black ice - 94-128 meters.
The second digit is the skid braking distance.
Any driver or motorcyclist should know the approximate stopping distance of their vehicle at different speeds. When registering an accident, traffic police officers can determine the speed at which the car was moving along the length of the skid.
