Classification of vehicle collision types. Tangent collision in an accident

Traditional division of road accidents by type

Collision

Hitting

Rollover

A fall

The interaction of a vehicle during a collision is determined by the forces arising during the contact process. Depending on the configuration of the contacting parts, they appear in different areas at different times, changing in size as the vehicle moves relative to each other. Therefore, their action can only be taken into account as the action of the resultant set of impulse vectors of these forces during the period of contact of the vehicle with each other.

Under the influence of these forces, mutual penetration and general deformation of the vehicle bodies occur, the speed of translational movement and its direction change, and a turn of the vehicle occurs relative to the centers of gravity.

The interaction forces are determined by the deceleration that occurs during an impact (acceleration during an impact in the same direction), which, in turn, depends on the distance at which the vehicles move relative to each other in the process of dampening the speed of these forces (in the process of mutual penetration). The more rigid and durable parts the vehicle was in contact with during a collision, the less (all other things being equal) the depth of mutual penetration will be, the greater the deceleration due to a decrease in the time of speed drop in the process of mutual contact.

Research to determine the relative position of vehicles at the time of a collision is directly related to solving questions about the location of primary contact and the sequence of damage formation. Having determined the location of the primary contact on the colliding vehicles, the expert determines the direction of deformation of the contacting parts. This is necessary so that the vehicles during the comparative study are positioned in the same way as at the time of the incident. First of all, on the vehicles under study, the location of the primary impact is determined, which presumably can be clarified even with a separate study - by the nature and direction of deformations in the damage. The issue is finally resolved through a comparative study of the vehicles involved in the collision.

Traces of primary contact are paired; in oncoming collisions, they are usually localized on the front protruding parts of cars on the bumper, headlights, car fenders, radiator; in case of passing collisions - on the rear protruding parts of one car and the front protruding parts of the other. Thus, the presence of a broken left headlight in one car, and a dent in the center of the front hood in another, indicates that these parts were the first to come into contact and the indicated damages are traces of primary contact. This conclusion can be confirmed, for example, by the presence of paint from the hood of a car on the headlight of another car and scraping of paint from a broken headlight in the area of a dent on the hood. The interaction process during contact is the second stage of the collision mechanism, which is established during the expert examination of traces and damage on the vehicle.

The main tasks that can be solved during an expert examination of marks and damage on a vehicle are:

1) establishing the angle of relative position of the vehicle at the moment of collision;
2) determination of the point of initial contact on the vehicle. The solution to these two problems reveals the relative position of the vehicle at the moment of impact, which makes it possible to establish or clarify their location on the road, taking into account the signs remaining at the scene of the incident, as well as the direction of the collision line;
3) establishing the direction of the collision line (the direction of the shock impulse is the direction of the relative speed of approach). Solving this problem makes it possible to find out the nature and direction of movement of the vehicle after an impact, the direction of the traumatic forces acting on passengers, the angle of collision, etc.;
4) determination of the collision angle (the angle between the directions of vehicle movement before the impact). The collision angle allows you to determine the direction of movement of one vehicle, if the direction of the other is known, and the amount of movement of the vehicle in a given direction, which is necessary when identifying the speed of movement and displacement from the collision site.

In addition, tasks may arise related to establishing the causes and time of occurrence of damage to individual parts. Such problems are solved, as a rule, after removing damaged parts from the vehicle through a comprehensive study using automotive, traceological and metallurgical methods. Determining the angle of relative position of the vehicle from deformations and marks on the vehicle with sufficient accuracy is possible during blocking impacts, when the relative speed of approach of the vehicle at the points of their contact drops to zero, i.e. when almost all the kinetic energy corresponding to the speed of approach is spent on deformations. It is accepted that in the short time of formation of deformations and damping of the relative speed of approach, the longitudinal axes of the vehicle do not have time to noticeably change their direction. Therefore, when combining the contacting surfaces of paired sections deformed during a collision, the longitudinal axes of the vehicle will be located at the same angle as at the moment of initial contact. Therefore, to establish the angle, it is necessary to find paired areas on both vehicles that were in contact during the collision (dents on one vehicle corresponding to specific protrusions on the other, imprints of characteristic parts). It should be borne in mind that the selected areas must be strictly connected to the vehicle. The location of areas on parts of the vehicle that are displaced and torn off during movement after an impact does not allow determining the angle if it is impossible to determine with sufficient accuracy their position on the vehicle at the moment of completion of the deformation upon impact.

The relative position angle is found in several ways.

1. Determination of the angle by direct comparison of vehicle damage. Having installed two pairs of contacting areas on the vehicle, located as far as possible from each other, place the vehicle so that the distances between the contacting areas in both places are the same.

With a direct comparison of the vehicle, it is easier and more accurate to determine the points in contact. However, the difficulty of delivering both vehicles to one place when they are not transportable, and the difficulty of placing them relative to each other, in some cases may make the use of this method inappropriate.

The method of measuring the angle depends on the nature of the deformations of the vehicle body. It can be measured between the sides of the vehicle, if they are not damaged and parallel to the longitudinal axes, between the axes of the rear wheels, between specially laid lines corresponding to undeformed parts of the vehicle body.

2). Determination of the angle based on the angles of deviation of the trace-forming object and its imprint. Often, after a collision, clear imprints of parts of the other remain on one of the vehicles - headlight rims, bumpers, sections of the radiator lining, the leading edges of the hoods, etc.

Having measured the angles of deviation of the plane of the trace-forming object on one vehicle and the plane of its imprint on the other (angles X 1 and X 2) from the direction of the longitudinal axes of the vehicle, the angle of relative position is determined by the formula:

L o =180+X 1 -X 2

where - L o is the relative position angle, measured from the direction of the longitudinal axis of the first vehicle.

The direction of counting angles in calculations is taken counterclockwise.

3). Determining the angle by the location of two pairs of contacting areas. In cases where there are no prints on the deformed parts of the vehicle that make it possible to measure the angles of deviation of the contact plane from the longitudinal axis, it is necessary to find at least two pairs of contacted areas located as far as possible from each other.

Having measured the angles of deviation from the longitudinal axes of the straight lines connecting these sections on each vehicle, the angle is determined using the same formula as in the previous case.

When the impact of a collision is sharply eccentric in nature, after the impact the vehicle rotates through a significant angle, and the depth of mutual penetration is large, the vehicle manages to rotate through a certain angle during the deformation, which can be taken into account using a special technique if high accuracy in determining the angle is required.

It should be borne in mind that during an eccentric collision, vehicles can turn in different directions. In this case, the angles must be determined for both vehicles and the correction is equal to the sum of these angles.

When turning vehicles of the same type (having similar masses) in one direction, the correction is a difference in angles and is very insignificant, so the calculation is impractical.

When a heavy vehicle collides with a lighter vehicle, the angle is determined only for the softer vehicle.

Impact during a vehicle collision is a complex short-term process, lasting hundredths of a second, when the kinetic energy of moving vehicles is spent on the deformation of their parts. During the formation of deformations during the mutual penetration of the vehicle, various parts come into contact, slipping, deforming, and breaking at different points in time. In this case, interaction forces of variable magnitude arise between them, acting in different directions.

Therefore, the force of interaction between a vehicle in a collision (impact force) should be understood as the resultant of the impulses of all elementary forces of interaction between the contacting parts from the moment of initial contact in a collision until the moment the deformation is completed.

The straight line passing along the line of action of the resultant impulses of the interaction forces is called the line of impact. Obviously, the line of impact does not pass through the point of initial contact of the vehicle during a collision, but somewhere near the point of impact along its strongest and most rigid section (wheel, frame, engine), in the direction of which the deformations propagated. It is practically impossible to establish the point through which the impact line passes through calculations, since it is impossible to determine the magnitude and direction of the force impulses that arise during the deformation and destruction of many different parts during a collision.

The direction of the impact line on a given vehicle is determined by the angle measured from the direction of its longitudinal axis counterclockwise. The magnitude of this angle depends on the direction of the relative speed of the vehicle at the moment of initial contact during a collision and on the nature of the interaction between the areas in contact during the collision.

In blocking collisions, when slipping does not occur between the contacted sections and the relative speed of their approach is damped during the deformation process, the direction of the impact coincides with the direction of the relative speed of the vehicle (the speed of approach of the contacted sections) and the general direction of displacement of the deformed parts.

In sliding collisions, when slipping occurs between the contacting areas and significant transverse components of interaction forces (friction force) arise, the direction of the impact line deviates from the direction of the relative speed towards the action of the transverse components of the interaction forces, which contributes to the mutual throwing of the vehicle from the collision site in the transverse direction.

In tangential collisions, when the transverse components of the interaction forces can significantly exceed the longitudinal ones, the direction of the line of impact can sharply deviate in the transverse direction, further contributing to the mutual throwing of the vehicle in the transverse direction.

It is practically impossible to establish calculations by deviating the line of impact from the direction of the relative velocity in sliding and tangential collisions, since it is impossible to take into account the resistance to the relative sliding of the contacting sections in the transverse direction during the mutual penetration of the vehicle during a collision.

Approximately, the direction of the impact line in such cases is determined by the general direction of displacement of the deformed parts of the vehicle, the direction of deformation on the other vehicle, taking into account the angle of the collision, the direction of the vehicle's turn after the impact, taking into account the location of the impact sites in relation to the centers of gravity.

The direction of the relative speed of a given vehicle is determined by the angle measured from the direction of its longitudinal axis counterclockwise.

The relative speed of the vehicle is equal to the relative speed of approach of the areas in contact during a collision, but not the speed of approach of the centers of gravity of the vehicle, which is the projection of the relative speed of the vehicle onto a straight line passing through their centers of gravity. The speed of convergence of the vehicle’s centers of gravity at the moment of collision can be zero or even have a negative value, depending on their relative position and direction of movement.

To determine the magnitude of the change in vehicle speed as a result of a collision and subsequent deformation, there is a technique (RF patent No. 2308078 for the invention “Method for calculating vehicle collisions”), which is more conveniently illustrated using the following example:

As a result of the accident, the 1st car was damaged on the right side;

To measure the magnitude of the transverse deformation, a white cord was stretched as a base from the gas tank flap to the front upper part of the right front fender of the car, as can be seen in photo illustration No. 1 (Appendix A). The cord was stretched so that on a non-deformed car, taking into account the convexity of the side surface of the car, it would certainly pass “through” the car. Thus, the amount of transverse deformation at any point between the posts, measured relative to the cord, is obviously less than the actual amount of deformation at this point. Next, 12 points were marked on the surface of the car according to the diagram in Fig. 1, and the amount of deformation in each of them was measured using a vertical rod installed near the cord, as the distance from the rod to a point on the surface of the car.

Figure 1. Scheme for measuring the deformation values of a car 1.

The transverse deformation values obtained by measuring are shown in the table below.

Table 1. Car deformation 1.

From Table 1 and photo illustration No. 1 (Appendix A) it is clear that the greatest deformations occur at the height of the threshold and above it, which corresponds to the location of the bumper of the 2nd car. - 2 car was damaged in the front;

An external inspection revealed that car 2 has damage to the front end in the direction predominantly from front to back. At the time of inspection, the car was partially disassembled, in particular, the hood was removed, the plastic trim of the bumper, doors, rear bumper and taillights were missing. The power elements of the front part, such as the side members and the bumper reinforcement, were in place. The thickness of the sheet material of the side members is 1 mm. No fatigue cracks or traces of corrosion were found on the vehicle's power components.

Photo Illustration 2 shows car 2 from the front right and a diagram for measuring its deformation. At a distance of 320 cm from the rear axle of the car, where there were no deformations or displacements of the car’s structural elements, a rail was laid on the floor. There are 5 points marked on the rack, located at a distance of 38 cm from each other so that the extreme points correspond to the edges of the front part, and the middle point corresponds to the longitudinal axis of the car. The numbering of points is shown in the photo illustration. Next, the distance from each point to the front of the car along the longitudinal axis was measured with a tape measure and amounted to, see Table 2.

Table 2. Deformation of car 2.

Point number
Deformation, cm

For subsequent analysis and calculations, the results of a crash test of a car analogue of car 2 for a frontal impact into a rigid non-deformable barrier at a speed of 56 km/h, carried out by a certified laboratory in the USA under the NCAP car safety testing program, of which Russia is also a member, are used.

Figure 2. Excerpt from page 32 of the crash test report.

Figure 3. Comparison of deformations of car 2 and crash test.

It can be seen that the magnitude of the deformation of the front part of car 2 in an accident only in the middle part is comparable to the magnitude of the deformation in the crash test, and to the left and right of the longitudinal axis the deformation values significantly exceed the deformations in the crash test. The actual mass of the laboratory vehicle in the crash test during testing was 1321 kg, and the actual impact speed was 55.9 km/h. Consequently, the energy expended on the deformation of the laboratory car is:

E = 1/2Хm(V/3.6) 2 = 1/2Х1321Ч(55.9/3.6) 2 = 159254 J;

where E is the energy expended on deformation, m is the mass of the car, V is the speed of the car. And the amount of energy expended on the deformation of car 2 in an accident was correspondingly greater than this value.

The rigidity of the side of car 1 is less than the rigidity of the front part of car 2, since the deformation value of car 1 - 70 cm in the middle part of the right side is greater than the deformation value of car 2 - 41 cm in the middle of the front part in

k = 70 / 41 = 1.7 times.

Due to the equality of action and reaction, the magnitude of the interaction force between the cars during the period of their deformation was the same for both cars. Consequently, the amount of energy (work of force) expended on the deformation of car 1 is k times greater than the amount of energy E 2 expended on the deformation of car 2, or

E 1 = kE 2 = 1.7Х159254 = 270732 J,

Where E 1 is the energy expended on the deformation of car 1, E 2 is the energy expended on the deformation of car 2.

The actual amount of energy spent on the deformation of car 1 was greater, since the amount of energy spent on the deformation of car 2 in an accident was greater than in the laboratory crash test.

Then the total amount of energy spent on the deformation of both cars in an accident is no less than

E = E 2 + E 1 =159254? + 270732 = 428986 J.

The weight of car 2 and the driver at the time of the accident was

M 2 = 1315 + 70 = 1385? kg.

The weight of car 1 and two people at the time of the accident was

M 1 = 985+2Х70 = 1125? kg.

Hence, the speed of car 2 as a result of the impact on car 1 changed by an amount of at least

DV 2 = 3.6 v(2EM 1 /M 2 (M 2 +M 1)) =

3.6Hv(2H428986H1125/1385H(1385+1125) = 60 km/h

The speed of car 1 as a result of the impact of car 2 changed by an amount of at least

DV 1 = 3.6 v(2EM 2 /M 1 (M 2 +M 1)) =

3.6Hv(2H428986H1385/1125H(1385+1125) = 74 km/h

This technique allows you to establish the circumstances of a traffic accident by calculating the collision of vehicles. The technical result is the determination of changes in the velocities of objects based on the expenditure of their kinetic energy on deformation during a collision. The technical result is achieved by determining the actual dimensions and shapes of deformed structural elements, representing the outer surfaces of colliding objects, or internal structural elements of objects, or a combination thereof, in the form of mesh models, solving a physically nonlinear problem by repeatedly solving a system of equations, calculating the change in object velocities based on from the expenditure of their kinetic energy on deformation during a collision.

The interaction of TC during a collision is determined by the forces arising during the contact process. Depending on the configuration of the contacted parts, they appear in different areas at different times, changing in size as the TC moves relative to each other.

Therefore, their action can only be taken into account as the action of the resultant set of impulse vectors of these forces during the period of contact TC with each other.

The more rigid and durable the TC parts were in contact during a collision, the less (all other things being equal) the depth of mutual penetration will be, the greater the deceleration due to a decrease in the time of speed drop in the process of mutual contact.

The average value of TC deceleration in the process of mutual penetration can be determined by the formula

The accuracy of the calculation results largely depends on the accuracy of determining the distance D, which can only be determined by traceological methods. To do this, it is necessary to determine the distance between the centers of gravity TC at the moment of primary contact during a collision and the distance between them at the moment when mutual penetration has reached its maximum value (until the moment the colliding sections leave contact with each other - in sliding collisions), and find the difference between these distances.

The deceleration value determined in this way is an average. Its actual value at certain moments can be much higher. If we assume that the increase in deceleration during a blocking collision occurs according to the law of a straight line, the final deceleration value will be 2 times higher than the calculated average.

The extent and nature of the deformations, as well as the displacement of the TC during a collision, depend mainly on three circumstances: the type of collision, the speed of approach and the type of colliding vehicles.

Formation of deformations. Depending on the type of collision, the location of deformations along the perimeter of the TC and their nature are determined (direction under the influence of contacting parts, general deformations of the body). In a blocking collision, the general direction of deformation coincides with the direction of the relative velocity vector; in a sliding collision, it can deviate significantly due to the occurrence of transverse components of interaction forces. The relative displacement of the centers of gravity TC during the formation of deformations during a sliding collision can be significantly greater than during a blocking collision, which reduces the interaction forces due to greater damping. In addition, during a sliding collision, a smaller part of the kinetic energy of the vehicle is spent on the formation of deformations, which also helps to reduce the interaction forces during a collision.

The overall deformation of the TC body during a collision is affected by the eccentricity of the impact: in an eccentric collision it is more significant than in a central one.

The speed of approach TC at the moment of collision has a great influence on the formation of deformations, since the deceleration in the process of formation of deformations is proportional to the square of the speed of approach. The higher the approach speed, the more significant both the overall deformation of the body and the deformation of the parts of the vehicle that were in direct contact during the collision.

The speed of approach of the areas in contact during a collision should not be identified with the speed of approach of the centers of gravity TC before the collision. In some cases, they can even be opposite in sign (for example, when a passenger car hits the rear wheel of a heavy truck, when the areas that were in contact during the collision came closer together at the moment the distance between the centers of gravity of the vehicle increased).

Since TC damage in a collision depends on the strength and rigidity of the contacting parts and their relative position, the type of TC has a great influence on their formation; Often, when a passenger car is almost completely destroyed, the truck with which the collision occurred has only minor abrasions without significant damage to its parts.

Change speed. Depending on the type of collision, the TC speed after the collision may sharply decrease (in the case of a head-on collision), increase (in the case of a rear-end collision), and the direction of movement may also change (in the case of a cross-over collision).

When the interaction forces during a collision act in the horizontal plane, the change in the speed of motion of the TC and its direction during the collision is determined by the condition that the resultant momentum of the two TCs before and after the collision is equal (the law of conservation of momentum). Therefore, the momentum vectors of each of the two TCs before and after the collision are guardians of parallelograms constructed on diagonals, equal in magnitude and direction to the momentum vector of both TCs (Fig. 1.2).

To determine the direction of movement or speed of a TC before a collision, it is very important to examine the direction of the tracks of the TC wheels immediately after the impact, which will allow us to establish the direction of displacement of the centers of gravity of each TC and the speed of their movement (by displacement and rotation around the center of gravity during the movement) after the impact.

Rice. 1.2. Scheme for determining the relationship between vectors of momentum TC before and after a collision

During a blocking eccentric collision, interaction forces act on the TC, resulting in a turn of the TC in the direction of the resulting inertial moment - the more sharp, the greater the eccentricity of the impact. In this case, if the collision is longitudinal, the center of gravity of the TC shifts from the line of impact and the TC acquires a new direction of movement by the time it leaves contact. After the collision, the TCs diverge at a certain angle to each other, if there is no adhesion between them, while simultaneously turning in the direction of the acting inertial moment.

In a longitudinal sliding collision, the resultant of the impulses of the interaction forces can significantly deviate from the longitudinal direction as a result of the “wedging” of the vehicle, when mutual rejection of the contacting sections occurs in the transverse direction. In this case, the TCs also diverge in opposite directions from the longitudinal direction, but the rejection of the contacted sections causes the TC to turn in the opposite direction if the resultant of the impulse vectors of the interaction forces passes in front of the center of gravity of the vehicle, or in the same direction if it passes behind.

The direction and speed of approach (relative speed) of the areas in contact during a collision are determined by the vector of the geometric difference between the speed vectors of their movement at the moment of impact (Fig. 1.3). The direction of this speed can also be established traceologically in the direction of the traces that appeared on the contacting parts at the initial moment.

The speed of approach affects not only the expenditure of kinetic energy on the deformation of vehicle parts, but also the change in the direction and speed of movement of the vehicle during contact.

The higher the speed of approach, the more the projections of the velocity vectors of both TCs onto the direction of this speed change (in accordance with the law of conservation of momentum).

Rice. 1.3. Scheme for determining the relative speed (meeting speed) TC in a collision

The influence of the type of colliding TCs on the direction and speed of their movement after the impact is due to the fact that parts that come into contact are different in strength, horizontal location and height, the nature of the interaction (deforming or collapsing, smooth or interlocking), etc. This contributes to the deviation of the resultant impulses of the interaction forces from the direction of the speed of approach both horizontally and vertically (when one TC “crawls” under the other).

The deviation of the resultant in the vertical plane leads to changes in the patterns of TC rejection during the collision. The vehicle, which will be pressed against the supporting surface by the vertical component of the interaction force, will experience greater displacement resistance due to increased adhesion of the wheels to the road surface and will move a shorter distance than with the horizontal direction of this force. Another vehicle, thrown up by the impact of the vertical component of the interaction force, on the contrary, will be displaced over a greater distance. Under this condition, the deviation of the direction of movement of the TCs and the speed of their movement after the collision may slightly differ from the law of conservation of momentum, unless one takes into account the fact that the displacement resistance forces during their contact could be unequal.

Therefore, when performing a traceological study of a TC after a collision, you need to pay attention to signs indicating that one TC is running into another, in which vertical components of the interaction force arise. Such signs are prints or traces left by parts of one vehicle on another at a height greater than the height of the location of these parts in the normal position of the vehicle; marks on the upper surfaces of the deformed parts of one vehicle left by the lower parts of another; traces of collision with wheels on top, etc.

The rotation of the TC during contact during a collision occurs during eccentric collisions, when the resultant of the impulses of the interaction forces does not coincide with the center of gravity of the TC and, under the influence of the inertial moment TC arising under this condition, manages to acquire an angular velocity.

In blocking collisions, the direction of the impact closely coincides with the direction of the relative speed of the vehicle sections that were in contact during the collision; in sliding collisions, the resulting transverse components of the interaction forces deflect the resultant in the direction opposite to the location of the section that was struck. The direction of the turn after the collision will depend on how the resultant passes relative to the center of gravity of the vehicle.

In expert practice, this circumstance is not always taken into account, which in some cases, in the absence of data on the traces left by the TC in the process of discarding after a collision, can lead to an erroneous conclusion about the direction of the TC turn and the mechanism of the incident as a whole.

During traceological research, it is necessary to identify signs of the nature of the collision (sliding or blocking). In a sliding collision, when the TCs come out of contact with each other before the relative speed drops to zero, longitudinal tracks appear following the main damage, the protruding or partially torn parts bend back when the deformations are completed; after an incident in the longitudinal direction, TCs are located on both sides of the collision site.

Signs of a blocking collision are the presence of traces on the contacted areas (imprints of individual parts of one TC on the surfaces of another) and a large depth of mutual penetration in a limited area.

The rotation angle during contact is, as a rule, small if the relative movement of the TC during mutual contact is insignificant, with low closing speed and blocking collisions, as well as with slight eccentricity of the impact.

A vehicle collision can occur in the following typical situations - there are seven of them:

- rear collision - a collision with the rear of a stopped car, its varieties;
- oncoming collision - cars are traveling exactly in the opposite direction and hit with their front parts;
- corner collision - an impact of one car into the corner of another, when the length of the contacting surfaces of the cars upon impact is 15 cm;
- side collision - a collision of vehicles on the sides, the length of the contacting surfaces of the vehicles is less than 15 cm;
- cross collision - cars collide at right angles;
- collision of several vehicles;
- collision of tractor-trailers with trailers and semi-trailers.

Based on the damage analysis, the type of collision is determined, which indicates the relative position at the time of the collision. Before the collision, each car moves in its own direction. During a collision, vehicles may move and rotate into positions they were in when they came to a complete stop, which have nothing to do with their position at impact.

After a rear-end collision, the cars may stop in a coupled state if it happened while moving or bounce off one another if one of the cars was stationary. One car will have the rear end damaged, the other the front end. Traces of damage on one car will match the damage on another.

In general, road transport crimes are a specific type of crime that represents the result of a failure in the operation of the “person - car - road - environment” system. “The complexity of the interaction of the elements included in this system determines the objective and subjective nature of the difficulties of the investigative process. Therefore, without the use of modern forensic and automotive knowledge, the successful detection and investigation of road traffic crimes is impossible.” Sidorov E.T. Increasing the reliability of forensic technical examination by clarifying its initial data//Investigator. - No. 3. - 1999, p. 45.. After all, “the correctness of the name of the examination and the formulation of questions by the investigator when appointing it can play a decisive role when considering a criminal case in court. This is especially important when investigating road traffic crimes, when the result of the examination is sometimes the evidence on which the entire investigation is based. ... When ordering any examination, the investigator must clearly understand what special knowledge is required to resolve the questions posed to him. If, to resolve any issue, knowledge in several areas of scientific knowledge is required, it is necessary to appoint a comprehensive examination” Kossovich A.A. Issues of appointment and production of automotive technical examination//Investigator. - No. 12. - 1999, p. 35..

The next type is an oncoming collision; it occurs quite rarely, as drivers try to dodge an oncoming impact. But they happen and have their own characteristics.

In such collisions, the cars stop at the point of impact or bounce an equal distance if their weight and speed were the same. If the weight and speed are unequal, a lighter or slower vehicle will be thrown back from the collision site. In such a collision, the cars do not rotate and the debris occupies a small area of the road. The main question in a collision is to find out on which side the collision occurred. The location of the collision in this case is determined by the location of the vehicles and the tracks of wheel sliding before and after the impact, taking into account the listed features.

There is evidence in the literature that: “analysis of a large number of road accidents made it possible to establish that for every 100 road accidents there are about 250 causes and related facts.

In the period of time immediately preceding a road traffic accident and during its development, the influence of each of the causes is not the same. In each phase of the development of an accident, one main, leading cause can be identified. In subsequent phases of the incident, this cause may become secondary, concomitant, and the main one becomes the one that was concomitant in the first phase. When analyzing a traffic accident, it is necessary to identify all cause-and-effect relationships. Otherwise, establishing the root cause of the incident is difficult and sometimes impossible. It is of no small importance to identify the circumstances preceding the road traffic accident. In many cases, the preconditions for an accident are created much earlier than the incident itself.

According to world statistics, the distribution of causes of road accidents is approximately as follows:

- due to incorrect human actions 60-70%;
- due to the unsatisfactory condition of the road and the inconsistency of road conditions with the nature of traffic 20-30%;
- due to a technical malfunction of the car 10-20%” Konoplyanko V.I. Organization and safety of road traffic: Textbook for universities. - M.: Transport, 1991, p. 16..

The next type is a corner collision, it is the most common accident and has its own characteristics. In such a collision, the vehicles typically spin after impact, leaving tire marks; when colliding with the left corners, the rotation occurs counterclockwise and the cars bounce off one another; when the right corners touch, as a rule, clockwise. The radius of scattering of parts and debris depends on the contact area of the mass of the vehicles, their speeds, and the condition of the road surface. In such a collision, the investigator must determine on which side of the centerline of the arc the collision occurred, since debris, glass debris, spilled oil and dirt can be scattered over a relatively large area. However, the location of the collision can be determined approximately, since in such a collision each vehicle moves away from the collision site towards its own side of the road.

A cross collision is characterized by the fact that braking marks indicate the movement of vehicles.

One car will have dents in the front, while others will have dents in the sides. Tire skid marks after a collision will reflect the speed of the vehicle. When considering an intersection collision, the investigator must decide which vehicle entered the intersection first. In this case, three options may occur:

- both entered the intersection at a constant speed (without braking);
- one entered the intersection at a constant speed, and the other braked;
- both drove out to the intersection and slowed down.

In the first case, the investigator needs to: measure the distance from the place (point) of the collision to the lines limiting the intersection, this allows us to determine the speed of the cars in the future. Based on the speed, it will be possible to determine the time it took each car to travel from the border of the intersection to the collision site. Time will indicate which car entered the intersection earlier and which later.

In the second case, determining the speed by braking and its length from the border of the intersection to the point of collision indicates who entered the intersection first.

In the third case, when both cars were braking before the collision, the length of the braking distance will indicate the speed of each of them and who entered the intersection first.

According to statistics, vehicle collisions “usually occur when overtaking a vehicle in front (every tenth case), when passing a stationary car (every twelfth case), when a vehicle is moving in the far left lane (every third case). The main reasons: incorrect calculation when passing or overtaking, driving into oncoming traffic, as well as driver overconfidence." Automobile transport. No. 1, 1996 // Ambartsumyan V. Causes of road accidents, p. 22-23..

Side collisions, like corner collisions, are the most common; In a side collision, the damage is usually minor and the cars are stopped by the drivers themselves. In a side impact collision, cars usually do not rotate. Reliable facts indicating the location of the collision are pieces of dirt that have fallen off the fenders, glass fragments and tire skid marks. The nature of scratches and dents in the sidewalls of the body, their directions can indicate the direction of movement of cars. In such a collision, the cars do not move to the opposite side of the road and the presence of both cars in one lane or another indicates the lane of the road on which the accident occurred.

Incidents and accidents, unfortunately, happen very often these days. This happens due to the large number of cars, inexperience of drivers, external reasons and other factors. Therefore, today we will talk about the concept, analysis, classification, main and other types of road transport, their characteristics, causes, consequences and types of responsibility.

So, how many types of accidents are divided into and how are they classified? The following types of road accidents are distinguished.

3 main factors of road accidents

This type of accident, collision, is one of the most common cases of accidents. In such an accident, a mechanical vehicle collides with another vehicle, with an animal or with.

Collisions between two MTS occur as follows.

Frontal.
Rear.
Lateral.
Tangents.

It is important to know:

The most dangerous of them are frontal ones. Most often they happen due to movement.
A rear-end collision can involve multiple vehicles. The most common reason is .
Side collisions are considered less dangerous, but they are very common. Usually happens at intersections due to.
Tangent collisions occur due to inattention during. Of all types, these accidents are the least dangerous.

Wherein:

In most collisions with railroad vehicles, the car driver is at fault. Such accidents are almost always fatal, because the driver does not have the opportunity to stop the train.
Collisions with animals most often occur outside the city at night. In these accidents, the car can receive severe damage, sometimes irreparable.

A specialist will tell you more about classic types of accidents in this video:

Depending on the object, there are the following types.

. A moving vehicle hits a person on the roadway or sidewalk.
To the obstacle. In this case, a collision occurs with a stationary object.
For a cyclist.
Currently MTS.
For horse-drawn transport. The car ran over a draft animal or its cart.

Collisions occur due to the carelessness of both drivers, pedestrians and cyclists. The situation with collisions in poor visibility conditions is getting worse.

Now let's talk about rollovers as a type of accident.

It happens more often on country roads where high temperatures are allowed. These accidents are unpredictable. Passengers, especially as a result of being hit by a car, can suffer severe injuries, even fatal ones.

In addition, the car may catch fire. The damage from such accidents is significant, often the car can no longer be restored.

A specialist will talk about the reasons for the formation of different types of accidents in the video below:

Point number

Deformation, cm

Point number

Deformation, cm

Falling from overpasses and bridges occurs as a result of force majeure, and as a result of the driver losing control. As a rule, the driver (under the influence of alcohol or drugs). In such accidents, even when falling from low heights, people rarely survive. These accidents are characterized by severe consequences, because random people who were at the scene of the fall may also die.

Falling loads can cause... Loads that are poorly secured pose a risk to road safety. The suddenness of the situation is especially insidious. The load falls from the car in front, and the driver of the car behind simply does not have time to react.

Read below about the types of injuries and damage to a car in an accident and the detailed classification. We talked about the types of topographic analysis of road accidents separately.

Statistics on different types of accidents

Transport and traceological examination of traces of damage studies the patterns of displaying information about the event of a road traffic accident and its participants in traces, methods for detecting traces of vehicles and traces on vehicles, as well as methods for extracting, recording and studying the information displayed in them.

LLC NEU "SudExpert" conducts traceological examinations in order to establish the circumstances that determine the process of interaction of vehicles upon contact. In this case, the following main tasks are solved:

establishing the angle of relative position of vehicles at the moment of collision
determining the point of initial contact on the vehicle
establishing the direction of the collision line (direction of the shock impulse or relative speed of approach)
determination of the collision angle (the angle between the directions of the vehicle speed vectors before the collision)
refutation or confirmation of contact-trace interaction of vehicles

In the process of trace interaction, both objects participating in it often undergo changes and become carriers of traces. Therefore, trace-forming objects are divided into perceiving and generating in relation to each trace. The mechanical force that determines the mutual movement and interaction of objects participating in trace formation is called trace-forming (deforming).

The direct contact of the forming and perceiving objects in the process of their interaction, leading to the appearance of a trace, is called trace contact. The areas of surfaces in contact are called contacting. A distinction is made between trace contact at one point and contact of many points located along a line or plane.

What types of vehicle damage are there?

Visible trace - a trace that can be directly perceived by vision. Visible marks include all superficial and depressed marks;
Dent — damage of various shapes and sizes, characterized by depression of the trace-receiving surface, which appears due to residual deformation;
Deformation - change in the shape or size of the physical body or its parts under the influence of external forces;
Badasses — traces of sliding with raised pieces and parts of the trace-receiving surface;
Layering — the result of transferring the material of one object to the trace-receiving surface of another;
Peeling — separation of particles, pieces, layers of substance from the surface of the vehicle;
Breakdown — through damage to the tire resulting from the introduction of a foreign object larger than 10 mm into it;
Puncture — through damage to the tire resulting from the introduction of a foreign object into it, up to 10 mm in size;
Gap — damage of irregular shape with uneven edges;
Scratch — shallow superficial damage that is longer than it is wide.

Vehicles leave tracks by applying pressure or friction to the receiving object. When the trace-forming force is directed normal to the trace-receiving surface, pressure noticeably predominates. When the wake-forming force has a tangential direction, friction dominates. When vehicles and other objects come into contact during a road traffic accident, as a result of impacts of different strength and direction, traces (paths) appear, which are divided into: primary and secondary, volumetric and surface, static (dents, holes) and dynamic (scratches, cuts ). Combined marks are dents turning into skid marks (more common), or vice versa, skid marks ending in a dent. In the process of trace formation, so-called “paired traces” arise, for example, a trace of delamination on one of the vehicles corresponds to a paired trace of delamination on the other.

Primary traces— traces that appeared during the initial contact of vehicles with each other or vehicles with various obstacles. Secondary traces are traces that appeared in the process of further displacement and deformation of objects that entered into trace interaction.

Volume and surface marks are formed due to the physical impact of the forming object on the perceiver. In a volumetric trace, the features of the forming object, in particular, protruding and recessed relief details, receive a three-dimensional display. In the surface trace there is only a planar, two-dimensional display of one of the surfaces of the vehicle or its protruding parts.

Static traces are formed in the process of trace contact, when the same points of the forming object influence the same points of the perceiver. A point mapping is observed provided that at the moment of trace formation, the forming object moved mainly along the normal relative to the plane of the trace.

Dynamic traces are formed when each of the points on the surface of the vehicle sequentially affects a number of points of the perceiving object. The points of the generating object receive a so-called transformed linear mapping. In this case, each point of the generating object corresponds to a line in the trace. This occurs when the forming object moves tangentially relative to the perceiver.

What damage can be a source of information about an accident?

Damage as a source of information about a road accident can be divided into three groups:

First group - damage resulting from the mutual penetration of two or more vehicles at the initial moment of interaction. These are contact deformations, a change in the original shape of individual vehicle parts. Deformations usually occupy a significant area and are noticeable during external inspection without the use of technical means. The most common type of deformation is a dent. Dents form at the places where forces are applied and, as a rule, are directed inside the part (element).

Second group - these are ruptures, cuts, punctures, scratches. They are characterized by through destruction of the surface and concentration of the trace-forming force on a small area.

Third group damage - prints, i.e. surface displays on the trace-receiving area of the surface of one vehicle of protruding parts of another vehicle. Prints are flaking or layering of a substance, which can be reciprocal: the peeling of paint or another substance from one object leads to a layer of the same substance on another.

Damage of the first and second groups is always volumetric, damage of the third group is superficial.

It is also customary to distinguish secondary deformations, which are characterized by the absence of signs of direct contact between parts and parts of vehicles and are a consequence of contact deformations. Parts change their shape under the influence of moment of forces arising in the event of contact deformations according to the laws of mechanics and resistance of materials.

Such deformations are located at a distance from the point of direct contact. Damage to the side member(s) of a passenger car can lead to distortion of the entire body, i.e., the formation of secondary deformations, the appearance of which depends on the intensity, direction, location and magnitude of the force during a traffic accident. Secondary deformations are often mistaken for contact ones. To avoid this, when inspecting vehicles, traces of contact deformations should first be identified, and only then can secondary deformations be correctly recognized and identified.

The most complex damage to a vehicle is distortion, characterized by a significant change in the geometric parameters of the body frame, cab, platform and sidecar, door openings, hood, trunk lid, windshield and rear window, side members, etc.

The position of vehicles at the moment of impact during a transport and traceological examination is, as a rule, determined during an investigative experiment on deformations resulting from a collision. To do this, the damaged vehicles are placed as close to each other as possible, while trying to align the areas that were in contact upon impact. If this cannot be done, then the vehicles are positioned in such a way that the boundaries of the deformed areas are located at equal distances from each other. Since such an experiment is quite difficult to carry out, the position of vehicles at the moment of impact is most often determined graphically by drawing the vehicles to scale, and by marking the damaged zones on them, the collision angle between the conditional longitudinal axes of the vehicles is determined. This method gives especially good results when examining oncoming collisions, when the contacting areas of vehicles do not have relative movement during the impact.

The deformed parts of vehicles with which they came into contact make it possible to roughly judge the relative position and mechanism of interaction of vehicles.

When a pedestrian is hit, the typical damage to a vehicle is the deformed parts that caused the impact - dents on the hood, fenders, damage to the A-pillars and windshield with layers of blood, hair, and fragments of the victim's clothing. Traces of layering of clothing fabric fibers on the side parts of vehicles will make it possible to establish the fact of contact interaction between vehicles and a pedestrian during a tangential impact.

When vehicles roll over, typical damage is deformation of the roof, body pillars, cab, hood, fenders, and doors. Traces of friction on the road surface (cuts, tracks, peeling paint) also indicate the fact of a rollover.

How is traceological examination carried out?

external inspection of a vehicle involved in an accident
photographing the general appearance of the vehicle and its damage
recording of faults resulting from a traffic accident (cracks, breaks, breaks, deformations, etc.)
disassembly of units and components, their troubleshooting to identify hidden damage (if it is possible to perform this work)
establishing the causes of the detected damage to determine whether they correspond to the given traffic accident

What to look for when inspecting a vehicle?

When inspecting a vehicle involved in an accident, the main characteristics of damage to elements of the body and tail of the vehicle are recorded:

location, area, linear dimensions, volume and shape (allow you to identify zones of localization of deformations)
type of damage formation and direction of application (allows you to identify the surfaces of trace perception and trace formation, determine the nature and direction of movement of the vehicle, establish the relative position of vehicles)
primary or secondary formation (allows you to separate traces of repair influences from newly formed traces, establish the stages of contact, and, in general, carry out a technical reconstruction of the process of introducing vehicles and the formation of damage)

The mechanism of vehicle collision is characterized by classification criteria, which are divided by traceology into groups according to the following indicators:

direction of movement: longitudinal and cross; the nature of mutual approach: oncoming, passing and transverse
relative location of the longitudinal axes: parallel, perpendicular and oblique
the nature of the interaction during impact: blocking, sliding and tangential
direction of impact relative to the center of gravity: central and eccentric

More detailed free consultation on transport and traceological examination can be obtained by calling LLC NEU "SudExpert"

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