A.A. Klyasova, Yu.I. Magaras - Sinop LLC, Moscow, Russia
A.V. Dobrinsky - OJSC Moscow Roads, Moscow, Russia
Building an intelligent transport system imposes certain obligations associated with the use of high technology to improve the quality of services at all stages of the creation and operation of road transport infrastructure. The construction and operation of roads, tunnels, bridges in many regions of Russia needs the most modern systems meteorological support, since weather conditions, especially in areas with an unstable climate, directly affect the condition of the road surface, which means convenience and, most importantly, safety traffic. Road administrations today are concerned about the rational and, at the same time, efficient spending Money and anti-icing reagents used in the winter maintenance of roads.
Thus, in recent years, weather forecasting has become a real reserve for reducing the negative consequences of the impact of adverse weather conditions on the road transport infrastructure. The advent of new technologies and technical means make it possible to integrate meteorological information into the operational activities of motor transport companies and the process of making managerial decisions with a significant economic effect.
Today, the meteorological system must provide not only accurate current weather data, but also the most correct weather forecast, adapted to a specific area and including not only general meteorological parameters, but also specialized data for the automotive industry, such as temperature and road surface conditions, including on bridges. , overpasses, in tunnels, etc. The next generation of meteorological systems goes even further - here we can already talk about predicting the likelihood of a risk situation caused by dangerous weather events, and on the assessment of possible damage to ground infrastructure.
In European countries and North America Weather forecasting systems have been used to manage transport infrastructure for more than 20 years. So in Germany, back in the early 90s of the last century, a centralized implementation of an information system for warning about the state of roads and predicted weather conditions based on National Weather Service forecasts and road sensor readings. Similar or similar meteorological systems are now used in the USA, Canada, Finland, Austria, and some other European countries.
In Russia today whole line highways are also equipped with road meteorological stations and sensors for the condition and temperature of the road surface, while the further development of the use of these systems directly depends on the development of data processing systems and decision support systems.
Only a systematic approach makes it possible to turn the quantity of installed meteorological equipment into the quality of management and decision-making by road management bodies and operating organizations.
The most famous international project for building ITS, including a weather forecasting system, is the intelligent transport corridor Helsinki - St. Petersburg - Moscow, which was launched by the governments of Russia and Finland. The automated meteorological support system to be created within the framework of the project will allow receiving current data from installed road meteorological stations, processing them in the situation center and informing road users about actual weather conditions different ways, including alerts on mobile devices, radio messages and data output to roadside information boards.
This approach largely solves the problem of the availability of up-to-date weather data for all road users, but the lack of accurate predictive information about weather and road conditions in any section of the transport corridor greatly complicates the decision-making process for drivers when choosing the optimal traffic schedule. Detailed detailed and localized forecast information is also essential for road services to implement operational and planned activities. Thus, the first steps to create an intelligent transport infrastructure are already being implemented, but this is only the beginning of the journey.
To better meet the needs of road users and road services in specialized hydrometeorological information (SHMI), it seems promising to create a specialized website with real-time publication of information about the actual weather conditions, weather forecasts and other types of SHMI in a form adapted for a non-specialist in the field. meteorology. Similar specialized site/portal that generates and integrates different kinds SHMI with the ability to localize data for a custom list of objects or a specific part of the road infrastructure based on an interactive software interface is given in this paper.
To create a product that satisfies modern requirements to the quality of the weather forecast and convenient for use by non-specialists in the field of meteorology, it is necessary to solve several fundamentally important tasks. Figure 1 shows the main problems in hydrometeorological support, typical for weather-dependent sectors of the economy.
Fig.1 Existing problems in the meteorological support of economic activity and ways to solve them
The first two are associated with insufficient detail of both measured and predicted parameters. By the necessary detail, we mean a fairly specific set of indicators with the appropriate temporal and spatial resolution. Such indicators include, in particular, the density of the observing meteorological network, the frequency of measurements, the measured parameters, the availability of specialized sensors, the information of which is necessary in a particular area of economic and economic activity. The spatial and temporal resolution of prognostic information, the frequency of its update, the list of predicted parameters also have a significant impact on assessing the development of the situation and making a balanced and informed decision. To serve the motor transport industry, a sufficient number of automatic road weather stations have been installed, which measure, in addition to the standard set of meteorological parameters, also the temperature and condition of the road surface. However, the practical use of data from road weather stations is at an extremely low level; if information about the current meteorological and road situation is used, it is rather due to the experience and intuition of the road transport industry workers.
Forecast information, as a rule, has a short lead time (4-6 hours), which allows, as a rule, to quickly respond to an unfavorable situation, but such lead time is insufficient for large-scale preventive measures that will minimize the effects of bad weather, as well as make planning realistic repair and maintenance work under the most favorable weather conditions.
The issue of rational and efficient use of meteorological information includes our proposals formulated in paragraphs 3 and 4 of the above figure. It is necessary to move from weather forecasting to forecasting weather risks, namely, to predicting certain consequences of the influence of adverse and dangerous hydrometeorological conditions on specific infrastructure facilities and reporting this information to the decision maker in a form that is convenient and understandable to a non-specialist meteorologist.
The vast majority of private meteorological providers, both in Russia and abroad, when preparing a forecast, use the results of those model calculations that are open to access. different providers in different countries they also prefer different models, which they consider either more accurate for a particular region or more convenient to use the results. However, any model calculations need to be "calibrated", i.e. in eliminating systematic error. This process must be constant and continuous and is based on the use of information about the actual weather, i.e. on weather station data. Accordingly, only the largest and most well-equipped providers, both technically and intellectually, can “calibrate” one model of their choice and only for settlements, from where they receive data on changes in the actual weather. This explains the possible diversity of forecasts for the same locality from different providers: the results were taken as a basis different models and different methods of eliminating systematic error were applied. It is fundamentally important to develop such a forecasting algorithm that would not rely on a single model, but would allow combining and combining the available forecasts of various forecasting systems. Essential additional and necessary conditions are the analysis of the spatial structure of prognostic and actual meteorological data and the generalization of algorithms for constructing "synthesized" forecasts for points of an arbitrary computational grid, in which there are no observational data. A similar problem is solved in the prognostic technology used in the system proposed below. Almost none of the providers provides the consumer with a service that takes into account possible Negative consequences complex joint impact of forecasted weather conditions directly on the activity of the industry with an assessment of the likelihood of such consequences. The decision maker does not have a tool for assessing possible risks caused by hydrometeorological events. Similar situation does not allow to effectively carry out the necessary measures aimed at the preliminary mobilization of forces and means to minimize possible losses and ensure normal operation the entire infrastructure. In our work, we also proposed a solution to this problem.
SINOP system today is a fundamentally new solution for Russia, which allows you to automatically make forecasts of the meteorological situation and weather risks in real time. The system consists of four main blocks, including weather forecasting, information and analytical tools, hydrometeorological risk forecasting and risk management.
Weather forecasting block. To monitor current weather conditions, data from almost all existing meteorological stations in Russia and Europe, as well as data from the customer's own automatic weather stations, are used. With the participation of the Hydrometeorological Center of the Russian Federation, a unique technology, which has no analogues in Russia, has been created for the automatic generation of a multi-model synthesized forecast of the main meteorological characteristics with a high degree detailing for an arbitrary geographic area. The system provides hourly weather forecast for 72 hours with hourly automatic updates. Today in Russia this is the most accurate local meteorological forecast, which is also used in forecasting special parameters - in the road industry, this is usually the temperature and condition of the road surface, the coefficient of adhesion (slipperiness).
All data is displayed on a geographical (transport) map, where zones are allocated heightened danger depending on the actual state of the weather or forecast conditions: black ice, ice, sticking wet snow or the formation of ice-frost deposits on the wires contact network urban transport and power lines, prolonged or intense precipitation, abnormally low or high temperatures and others (Fig. 2 and 3).
Fig. 2.3 Displaying the forecast of meteorological elements and areas of increased danger on a geographical map. All information in one window.
Information-analytical block. This block is responsible for the identification and formalization of weather risks for a certain industry infrastructure and the subsequent formation of a weather risk matrix that reflects the possible consequences (Fig. 4). Based on data on the causes, nature and parameters of newly occurred events caused by adverse meteorological conditions, the risk and damage matrix is adjusted.
Fig.4 Example of a simplified weather risk matrix
The flat matrix given above is rather conditional. In fact, such a matrix is multidimensional, since usually takes into account not one, but several qualitative factors that affect the derived event, and each of these factors may also have a quantitative characteristic or range of values. Moreover, with a well-formalized description of specific infrastructure facilities, a quantitative forecast of damage, expressed in financial terms, is also possible. As an example of a multidimensional approach to the formation of the concept of "event forecast", we will cite such a well-known phenomenon for motorists as "black ice". "Black ice" - a type of winter slipperiness that occurs on a dry surface highway in the form of an ice film due to the sublimation of water vapor from the air at a road surface temperature below 0°C and below the dew point temperature. This definition is given from ODM 218.8.001-2009 " Guidelines for specialized hydrometeorological support road infrastructure". Even from this short definition, it can be concluded that black ice forms under certain combinations of air temperature and humidity, pavement temperature and in the absence of precipitation. These conditions are necessary, but not always sufficient. Local features, previous weather, time of day, cloudiness, etc. As a first approximation, the conditions for the formation of black ice can be written as follows, which is shown in Fig.5.
Fig.5 A simplified example of the formation of the conditions for the occurrence of black ice according to the given meteorological parameters.
A map showing areas where black ice formation is predicted, automatically built based on the forecast of meteorological parameters and specified conditions, is shown in Fig.6.
Fig.6 Territory subject to black ice formation according to weather forecast and risk matrix.
Forecasting weather risks. To solve this problem, within the framework of the SINOP system, a technology has been created for automatically generating a specialized forecast of the place and time of occurrence and further development risky situation. The forecast is made in real time based on the interaction of weather forecasting and analytics blocks. Based on the forecast of the hydrometeorological situation and the weather risk matrix in automatic mode possible consequences of the impact of adverse weather conditions on infrastructure facilities are predicted. A flexible interface allows you to set specialized criteria for adverse conditions, forms of presentation of meteorological data, definition of algorithms for notification of occurred and predicted events. At the same time, the user can independently determine and adjust the criteria for the level of danger for each of the significant meteorological parameters or the complex effect of the total impact of several of them on the infrastructure.
Fig.7 Different colors show the areas of automatically predicted various hazardous weather-dependent events.
The system automatically sends messages about predicted and occurring dangerous or unfavorable hydrometeorological phenomena for the transport infrastructure, as well as about the predicted consequences in real time, including to mobile devices.
Additional integration of the SINOP system with GIS and BI systems allows expanding analytical capabilities, including for assessing the probability of occurrence and extent of damage.
Management of risks. In addition to forecasting weather risks, the system provides information necessary for operational planning. The system implements the functionality of assessing the estimated damage and the resources necessary for restoration, tools to support the development of optimal weather-dependent management decisions, taking into account the probabilistic assessment of the scale of the consequences of the predicted risk. The system also integrates a standard scenario of behavior and decisions that must be made in the event of a specific combination of weather and road conditions. This is important, firstly, to reduce the influence of the human factor and incorrect assessment of the situation, and secondly, for the promptness of decision-making.
However, it is important to understand that the mere fact of having a meteorological system is not able to affect the efficiency of the enterprise. The effect of using the system largely depends on the company's strategy in the field of response to forecast dangerous hydrometeorological events. To solve this problem, it is necessary to comprehensively develop not only the meteorological content of the system, but also the methodology for using meteorological data (determining the critical values of meteorological parameters according to the degree of impact of a dangerous hydrometeorological phenomenon on infrastructure, compiling risk matrices and forecast maps of the impact on infrastructure). However, the key step that determines the success of the meteorological system is the development of a structured and comprehensive set of measures to manage weather risks, including the distribution of authority among decision makers (DMs). It should be taken into account that the inconsistency of the interaction between decision makers different levels is an independent risk factor that increases the degree of damage from hazardous weather conditions.
The SINOP system is today one of the most modern intelligent meteorological systems, on the basis of which it is possible to create an integrated solution for managing road transport infrastructure. On the general transport map, in addition to meteorological data, it is possible to place images from photo and video cameras, traffic indicators, infrastructure facilities, information about the location of service teams and other data. Thus, all the information necessary for effective control of the situation on the roads is available in real time and in a single information system, which fully fits into the framework of the concept of building an intelligent transport system.
Literature:
1. ODM 218.8.001-2009 "Methodological recommendations for specialized hydrometeorological support of the road sector". Approved by the Decree of Rosavtodor dated November 26, 2009 N 499-r.
Always put safety ahead of punctuality. It is better to arrive at your destination later, but safe and sound, than to take unnecessary risks. We hope the following will help you tips for driving in difficult situations- let's talk about the features of driving in various adverse weather conditions: in heavy rain, wind, ice and snow.
Before you hit the road... Study your car. Plan your route and memorize it so you don't have to follow signs or a map to find your way. Tune the radio to the information channel "For those who are on the road."
Features of driving a car in any weather
These driving tips are relevant for any bad weather. In bad weather, the main rule is to limit speed and keep your distance. This feature of driving a car is important both in wet weather and in frost, when braking distances much longer. If visibility is limited due to fog, rain, or snowstorms, stay well away from the vehicle in front. If you can't see further than 100m, turn on your headlights.
On a wet road, the stopping distance is twice as long as on a dry one. In wet weather at 64 km/h, maintain a braking distance of at least 60 m (six vehicle lengths more than in dry weather) and preferably three times the braking distance.
Strong headwinds can cause the vehicle to sway. In addition, wind-broken tree branches and other debris may fall onto the road. Keep your eyes peeled for danger, and keep a firm grip on the steering wheel with both hands. Be especially careful if there are cars with trailers and bicycles on the road.
Large vehicles can protect from the wind while you overtake them. At the end of the maneuver, be prepared to withstand a sudden gust of wind.
Prepare your car for bad weather. Do not drive in extreme weather unless absolutely necessary. focusing on the following aspects:
- Clean the windshield and mirrors, remove ice from all windows.
- Check the battery.
- In winter, use antifreeze and windshield de-icer.
- Check tire pressure and treads, including spare tire.
- Check all bulbs, including fog lights.
What will be needed. De-icer, scraper, mobile phone, flashlight, tow rope, heavy-gauge wire to start the engine from foreign source energy, jack and spare wheel, shovel, sign emergency stop, burlap for lining under stuck wheels, warm clothes, a blanket, hot drink, in heavy snow - a wheel chain.
Snow and ice: features of driving a car in winter
Prepare carefully for your trip and drive with great care to avoid side slip and skid.
Wear comfortable dry shoes which will not slip on the pedals. Do not get underway until the windshield has thawed out (about frozen car windows). Brush the snow off the roof.
Careful maneuvering and constant speed This is exactly what is needed to move forward. Drive away in second gear to avoid slipping the drive wheel. If in the car automatic transmission gears, see if you know how to downshift to be less dependent on the brakes. If you have a "winter" shift mode, select it: it locks the first gear to reduce the slip of the drive wheel.
Drive the car at a low speed, at the highest possible transfers, do not brake or accelerate abruptly. Before braking, downshift faster than usual, and then, in the absence of an anti-lock braking system, apply the brake carefully and rhythmically.
When the road is covered with a transparent ice crust, slow down. If the car skids when braking and you have mechanical box gear, release the brake and engage the clutch.
To enter a slope, drop the gear, and then ascend at a constant speed. Go down hills in low gear so you don't have to brake.
Brake before a turn where it is easy to lose control. Do not twist the steering wheel, drive smoothly.
If the car is stuck in the snow, straighten the steering wheel, shovel the snow from under the wheels, place the burlap in front of the drive wheels and gently depress the accelerator pedal. Once the car has moved, keep moving until the road improves.
In a blizzard, when the windshield wipers can't handle the snow, look for shelter. Heavy snowfall can make roads impassable in minutes.
If you are locked in a car, wrap yourself in jackets, blankets, even newspapers are good. Save fuel by turning on the engine and heater for 15 minutes every hour with the window slightly open. Try not to sleep. If you are stuck in the company of other drivers, team up in one car to keep warm.
provide twice as big braking distances.
Slightly from time to time press the brake pedal: the friction will help keep the brakes dry.
Drive with dim headlights to reduce the glare of the road surface.
If the tires have insufficient grip on the road, the vehicle may skid. Do not brake, but slow down the engine speed to gradually slow down. Keep a firm grip on the steering wheel: when the tire grip is restored, the car may swerve.
In this article, we will consider the features of driving a car in difficult road conditions, more precisely, in conditions limited visibility.
What conditions for driving on the roads can be classified as difficult? For example, a clear day, visibility - to the horizon, few cars on the road, no pedestrians. This normal conditions or complex? Or, the same day, but there is heavy traffic and a lot of heavy vehicles on the road.
Or, for example, all this happens either during rain or fog. Or, worse, in the snow. It is impossible to answer unambiguously. In addition, the usual situation for an experienced driver may seem difficult for someone who has recently got behind the wheel. And that's okay.
Difficult road conditions are, in general, a combination of factors that may result in or insufficient visibility, or vehicle controllability deteriorates.
This may include
- weather conditions (rain, fog, snowfall, bright sun, ice);
- traffic conditions (oversized vehicles: trucks, tractors with semi-trailers, buses; intersections and roadside areas with limited visibility; closed turns, climbs; objects near the road: trees, bushes, standing transport, buildings, etc.)
- in fact, the car itself (everything inside the cabin can interfere with the view, as well as the performance of individual components, such as a windshield washer, wiper, interior heater, glass heater, etc.).
All of these factors have one thing in common: in such situations, different reasons it is always difficult to see the traffic situation, i.e. we can safely say that visibility is limited or insufficient. These two phrases have different definitions (they need to be remembered to solve), but in life, in relation to traffic situations, It is the same.
Another nuisance when it rains is a puddle. Its insidiousness lies in the fact that it can turn out to be both shallow and deep, hiding a hole under it, all sorts of bumps, stones, etc. And the closer this puddle is to the side of the road, the greater the layer of dirt on its bottom. Never try to cross a puddle on high speed You risk losing control. In addition, water may enter engine compartment, and this is fraught with problems in the electrics and electronics, up to the point that the engine can stall.
Before you enter this puddle, you must slow down in advance. And after leaving the puddle, especially if it turned out to be deep, you need to remember to check the brakes and, if necessary, dry brake pads by pressing the brake pedal several times while driving.
When it rains often and heavily, it seems that everything around seems to be immersed in fog. If this happens at night, then visibility is further complicated by the reflection of the light of oncoming headlights from wet road. You need to drive in heavy rain as carefully as when driving in fog. True, in the case of rain, properly working windshield wipers come to the rescue.
Wiper blades should fit snugly against the glass so that there are no blind spots on the surface, but they only work well on clean glass when enough rain water or washer fluid. Therefore, if on windshield there are traces of dried dirt (for example, from insects, if the bird did not miss, etc.), then it would be better to remove this dirt manually. Either with water, or with cleaners. If the brushes are worn out and do not do the job, they should be replaced.
Driving in heavy snow
When it goes dense snow, then the same feeling is created as in heavy rain - there is a white wall ahead, especially if the snow has already covered the ground and does not melt. What can be seen around? Shadows, contours, lights. Everything is in a fog. When the snow is heavy, the only thing you can see is the right side of the road, perhaps the center line will be visible, parking lights front cars, which, by the way, will periodically be lost in the snow. Visibility, again, is poor.
What can be done to improve visibility by choosing traffic tactics? Again - slow down! Move so that it is possible in case of danger to stop within your sight. Increase your distance. Remember that in conditions of limited visibility, you need more time and space to make any maneuver and stop.
If visibility is so limited that you are not able to correctly determine the location of other road users on the roadway, it is best not to risk putting yourself and others at risk. It's better to leave the road, finding for this comfortable spot, and wait there to improve visibility conditions. Nothing urgent is worth the risk. And when you stop, don't forget to turn on alarm.
In the next article, we will consider the features.
Navigating a series of articles
This winter is the real test for motorists. The constant change of weather - from severe frosts to thaws, after which the temperature drops sharply - contributes to a sharp surge in accidents, including fatalities.
The leadership of the traffic police urges drivers not to travel on the roads in bad weather conditions without extreme need common use, however, it is difficult for many to follow this advice: someone needs to get to the workplace, while for others, work is completely connected with car trips.
Interviewed experts from among traffic police officers and motor sportsmen believe that it is possible to drive in winter and avoid accidents, however, for this, the driver needs to adhere to elementary safety rules and keep his car in good technical condition.
But even the most experienced drivers from time to time make mistakes when driving a car, which lead to the fact that the car slips, “breaks” from the trajectory, and it can also skid or even turn around. The critical condition of roads complicates the situation: they are not cleaned of snow and ice always and not everywhere, but in those places where snowblower nevertheless passed, deep holes are exposed in place of the snow cover.
To prevent accidents, the driver needs to learn special driving techniques that will help get out of a critical situation and, quite possibly, save life and health.
Features of driving a car in winter
START OF MOVEMENT. First of all, concentrate: if there is ice under the wheels, you should refuse to talk on your mobile even with the help of “hands-free”. After starting the engine, start very carefully, pedaling as smoothly as possible, and if there is clean ice under the wheels, slightly covered with snow, it makes sense to try to move off from second gear. Standard winter accident - the car "led" when starting off, as a result of which the neighbor's car was damaged.
SPEED. In bad road conditions, the speed of the car should be, first of all, safe - according to the traffic rules, this is the speed at which the driver in specific road conditions is able to avoid an accident in a suddenly changed situation. And do not confuse it with the permitted one - it is far from always possible to stop in time at a speed of 60 or 80 km / h in front of a pedestrian who suddenly jumped onto the road. Define safe speed easy: before driving on a public road, try emergency braking and evaluate how much the braking distance has increased compared to the usual reaction of the car, as well as at what speed and with what effort on the brake pedal the car maintains its trajectory.
DISTANCE AND INTERVAL. One of the main rules to remember slippery road, - you must always leave enough room for maneuver and avoid sudden maneuvers. The fact is that snow or ice almost halve the grip properties with the road, respectively, the braking distance increases, which means that you need to keep a distance to the car in front of one and a half to two times greater than usual. Please note that even if you drive a super modern car with studded tires and a lot of electronic systems security, the old Zhiguli in front can suddenly turn 360 degrees, and in the event of a collision, it is you who are found guilty - for violating clause 12.3 of the traffic rules (in the event of a danger or obstacle, the driver is obliged to reduce speed until a complete stop).
BRAKING. Hard hitting the brake pedal on a slippery road is one of the most common mistakes novice drivers make. The fact is that if the car is not equipped with ABS, the wheels are blocked and the car that has lost control will, at best, skid another 100-150 meters, at worst, the car in front will stop. But even if it prevents slipping anti-lock system, pressing the brake pedal while turning the steering wheel will cause the car to turn 180-360 degrees. You need to brake in short strokes - press the pedal hard and release it several times until the car stops completely, and slow down by gently and lightly pressing the pedal. To improve braking performance, use engine braking by rapidly shifting from up to down a gear (for example, from 4th to 2nd and immediately to 1st). And one more piece of advice - do not press the clutch pedal until the car comes to a complete stop; even if the engine stalls, the saved centimeters will save you from a collision.
Efficient taxiing
To come out dry emergency, the driver must correctly act on the steering wheel. Strange as it may sound, for this he must first of all choose proper fit. Sit in a chair, lean against the back of the seat, depress the clutch pedal and put your outstretched hands on the steering wheel - your wrists should lie on the rim: this position will make it possible not to get confused when intercepting the steering wheel and allows you to work normally with the pedals and gearshift lever. An experienced driver holds the steering wheel without pushing away from it at all, while firmly pressing against the seat back, which allows him to resist the action of inertia. And an inexperienced one “hangs” on the steering wheel, and if the car does not fit into the turn, then turning the steering wheel can be quite difficult for him, since the steering wheel is used by him as a fulcrum.
You can get the necessary skills for proper taxiing on a simulator at any driving school, or on your own, with the help of a simple exercise: hang the front wheels (raise the car on a jack or platform) and turn the steering wheel from lock to lock for a while. "Wound" on roads over 30 thousand km, five cycles "from lock to lock" are performed in 15-16 seconds, and "athletes" - in 8-9 seconds. A conditioned reflex is acquired in 2.5 hours of exhausting labor, then triggering in an emergency.
Counter-emergency tricks: control the car with the steering wheel and gas
The most important task of the driver when driving on slippery surfaces is to prevent skidding, and if it does occur, control it and confidently align the trajectory. In order for the car not to lose its trajectory, you need to drive “smoothly”. Plan your actions in advance, look both ways and slow down in case of any change in the road surface. He turned the steering wheel sharply, entered the turn at too high a speed, or went too far with acceleration or braking - any of the listed driver errors can provoke a loss of trajectory.
There are two main types of drifts. The actual skid (or oversteer) occurs when the front wheels cover a distance shorter than desired, and rear wheels takes it to the side. This is the result of lateral forces that weaken the grip of the rear wheels with the road. Drift (or understeer) can occur if the front wheels are turned at an angle too great for the driving torque in this moment time. Then the front wheels continue to slide in the original direction, despite the steering wheel.
REAR DRIVE. For example, when moving in a straight line back the car starts to skid to the left, and it seems to be trying to turn around across the road. In this case, do not depress the clutch and brake, but do not sharply reduce the fuel supply, reduce speed and gently and clearly turn the steering wheel to the left. The vehicle, under the action of a slightly reduced traction force on the driving rear wheels and with the front steered wheels disengaged, will return to its original direction of movement.
In this case, it is necessary to align the trajectory with the steering wheel if the previous steering wheel turn is excessive. If the steering wheel is turned too sharply and excessively, then the car may skid in the opposite direction. In this case, skidding is prevented by a similar method of turning the steering wheel to the right and then moving into a straight line.
FRONT-WHEEL DRIVE. When skidding a front-wheel drive car, the driver must turn the steering wheel in the same way as on a rear-wheel drive car, but in no case reduce the fuel supply. Moreover, it is necessary to step on the gas - in this case, the drive wheels will pull the car in the direction of travel. In this case, there is no need for corrective actions by the steering wheel.
However, increasing speed in and out of a corner can cause front wheel spin. As soon as they lose traction, they will stop directing the car, and, having become uncontrollable, it will move along a curve that is more gentle than necessary - demolition occurs and an increase in the steering wheel angle will not work in this situation. To restore the adhesion of the wheels to the road and return the car to movement in the direction given to it, it is necessary to gradually reduce the fuel supply until the adhesion of the driving wheels to the road is restored and then push it a little.
Note that we have only described the theory of drifting out of a skid (drift). In order to put it into practice, practical skills are needed, which can only be obtained in courses of counter-emergency driving, which are held in closed areas and under the guidance of professional instructors.
If the wheels are spinning
One of the most common seasonal troubles that almost all drivers without exception fall into (from owners of small cars to owners of jeeps) is snow and ice captivity, when the car, no matter how you turn the engine, is “neither here nor there”. In most cases, it is enough to ask passers-by to push the car from behind, but if this does not help, you have to get a shovel and dig.
DRIVE WHEELS HAVE STOCKS. You need to dig out the wheel that is slipping. And look - if its levers, the drive did not lie down on the snow. Lie down? So, you need to dig under them. Then, for both driving wheels, you dig ruts - in front of the car and behind it - 50 centimeters in each direction. If possible, it is better to put gravel in the rut, pour sand or lay them with branches. And then, rolling, without revving, get out tight on a solid place.
THE VEHICLE SIT ON THE BOTTOM. Look under the car - there should be a gap. No? Dig with a shovel until he appears. Sometimes it makes sense to jack up the drive wheels in turn and pave the tracks described above under them. But only for the jack you need a support, which can be used as a spare wheel disc. Dig a place under it in the snow under the jack nest, line it with improvised materials (branches, gravel) or a rug from the passenger compartment, and a spare tire on top. Put a jack on it, raise the wheel and clean under the bottom to firm ground.
Driving on the track
Caught on slippery or snow covered road, you need to forget about fast driving and it is best to stay in the middle or right lane. It is better to remember that if on a dry road at a speed of 60 km / h the stopping distance of a car is 40-45 m, then on a slippery one it increases to 90-140 m. Also consider the condition of the road: the width of the carriageway, the presence of steep ascents, descents , turns, traffic intensity, time of day, illumination, visibility, technical condition of the car, and finally, one's own well-being. Please note that after a long drive at high speed, addiction occurs: after driving at a speed of 100 km / h, a decrease to 50 km / h almost gives the impression of a car stopping. However, the subjective impression is deceptive - be guided by the instruments.
Be careful when passing oncoming traffic: often drivers experience a feeling of insufficient width of the road and, in order to avoid an apparent collision, at the moment of passing they try to sharply maneuver the steering wheel, which can lead to an accident. Also note that the perspective of the road can be distorted: gentle ascents that follow long descents appear steep, and smooth turns from afar they look like sharp bends.
Riding in fog and snowfall
When driving in conditions of limited visibility, it is important for the driver to indicate his presence to other road users. Firstly, turn on the rear fog light and, even during the day, the dipped headlights, which will also allow you to see the car stopped in front in time and safely go around it.
If you can’t see very well, it is recommended to turn on the emergency gang: a flashing light makes the driver-observer rear car focus on the signal and decide important question whether the vehicle is moving or not. By the way, if you need to stop on the side of the road, leave the dimensions, emergency gang on, and it is advisable to set an emergency stop sign 50 m away.
The front fog lamps (if installed) make it easier to control the machine, and if visibility is less than 100 m, turn on high beam together with fog lights (when driving with oncoming cars, the high beam is switched to low beam, and the fog lights are extinguished). When moving in the fog, try to get behind big car, which somewhat dispels the fog, not forgetting, of course, about the distance. Note that if visibility does not exceed 10 m, then the speed should not exceed 5 km/h.
Particular care should be taken at traffic lights: fog not only impairs visibility and orientation, but also distorts the perception of yellow and green light rays (yellow appears reddish and green appears yellowish). Also, special attention is required to unregulated intersections: even if you have an advantage (follow the main road), slow down - a "Schumacher" coming from the right or left may not see the sign (often they are not lit) and provoke an accident.
OGAI Severodonetsk GO GUMVD
Many of the novice motorists, and even experienced motorists, do not always know how to properly and safely drive a car in difficult road conditions, the main of which are driving in ice, heavy rain, fog (limited visibility conditions), and also, in snowfall, or on a winter road.
cornerstone safe management vehicle in all road conditions, and especially in difficult ones, is a good technical condition car, the correct operation of the windshield wipers and lighting devices, as well as the conformity of the type of tires with the season and climatic features region.
Fog
When driving in the fog, or in conditions of limited visibility, it is imperative to reduce the speed of movement to a level that allows you to make emergency braking of the car in front of a possible unexpected obstacle.
In addition, additional lighting fixtures, or fog lights, and as an additional source of attracting attention, turn on the alarm, which will attract the attention of other road users and create an additional safety zone.
It is strongly not recommended when driving a car in conditions of limited visibility, the use of high beam headlights as a source of additional lighting, because in this case, high beam, not only impairs visibility, but also leads to increased fatigue of the driver's eyesight.
Rain
Heavy rain, makes its own adjustments to any movement, so, when driving in rainy weather, it is necessary to reduce the speed of movement and increase the distance to the car in front.
Avoid sudden lane changes, accelerations, and braking, trying to drive the car as straight as possible, and in the event of a hydroplaning effect caused by a sharp deterioration in contact car tires With pavement, it is necessary to smoothly and gradually release the gas pedal, thus carrying out soft braking, and resuming contact of the tires with the coating.
A good solution would be to turn on additional light sources, and in case of very heavy rain and an alarm.
Ice
When driving on ice, and under conditions heavy snow, you should take into account the increased braking distance, therefore, the distance to the vehicle in front should be as large as possible.
Strictly prohibited sharp accelerations, braking and rebuilding, all these maneuvers performed in ice and snow, even on a flat road, inevitably lead to a loss of traction, and the subsequent breakdown of the car into a skid.
The speed mode of movement must be chosen not only on the basis of overall speed traffic flow, but also taking into account the individual properties of the car, as well as the type of installed car tires.
It is necessary to carefully monitor the operation of the engine and the driving mode, while it is advisable to keep the engine speed at a level close to the beginning of the maximum engine thrust level - because in this case, with an unexpected skid, by sharply pressing the gas pedal, you can increase the engine thrust to maximum, and immediately get out of the starting skid.
