Determination of the angle of relative position of vehicles at the moment of collision. Determining the location of a vehicle collision. Classification of collision types

The ability to resolve the issue of the location of a vehicle collision by expert means and the accuracy with which it is possible to determine the location of each vehicle on the road at the time of the collision depend on what initial data about the circumstances of the incident the expert has and how accurately this location is determined.

To determine or clarify the location of the vehicle at the moment of their collision, the expert needs the following objective data:

About the traces left by the vehicle at the scene of the accident, their nature, location, length;

About traces (paths) left by objects thrown away during a collision: parts of the vehicle that separated during the impact, cargo that fell out, etc.;

About the location of areas of accumulation of small particles that have separated from the vehicle: soil, dirt, glass fragments, areas of splashing liquids;

About the location after a collision of the vehicle and objects thrown away during the collision;

About damage to the vehicle.

In most cases, the expert has only some of the listed data.

It should be noted that, no matter how conscientiously the situation at the scene of the accident was recorded by persons who do not have experience in conducting automotive technical examinations (or do not know the methods of expert research), omissions cannot be avoided, and they are often the reason for the impossibility of determining the location of the collision. Therefore, it is very important that the inspection of the scene of the incident is carried out with the participation of a specialist.

When inspecting and examining the scene of an accident, first of all, it is necessary to record those signs of the incident that may change during the inspection, for example, signs of braking or skidding on a wet surface, traces of the movement of small objects, tire tracks left when driving through puddles or leaving the roadside, areas of sprinkled earth during rain. The location of the vehicles should also be recorded if it is necessary to move them to provide assistance to victims or to clear the roadway.

Determining the location of a collision using tracks Vehicle

The main signs by which the location of a collision can be determined are:

A sharp deviation of the wheel track from initial direction which occurs when there is an eccentric impact on the vehicle or when the front wheel is hit;

Transverse displacement of the track that occurs during a central impact and the unchanged position of the front wheels. With a slight transverse displacement of the track or its slight deviation, these signs can be detected by examining the track in the longitudinal direction from a low height;

Traces of lateral shift of unlocked wheels are formed at the moment of a collision as a result of the lateral displacement of the vehicle or a sharp turn of its front wheels. As a rule, such traces are hardly noticeable.

Termination or breaking of the skid trail. Occurs at the moment of a collision due to a sharp increase in load and a violation of the wheel lock or separation from the road surface;

The skid mark of one wheel that was hit jammed it (sometimes only for a short period of time). In this case, it is necessary to take into account in which direction this trace was formed, based on the location of the vehicle after the incident;

Traces of friction of vehicle parts on the coating when its chassis is destroyed (when a wheel comes off, the suspension is destroyed). They begin mainly near the collision site;

Traces of movement of both vehicles. The location of the collision is determined by the intersection of the directions of these tracks, taking into account the relative position of the vehicle at the time of the collision and the location of the parts on them that left marks on the road.

In most cases, the listed signs are barely noticeable, and during inspection of the scene of the incident they are often not recorded (or recorded insufficiently accurately). Therefore, in cases where the exact location of the collision is essential to the case, it is necessary to conduct an expert examination of the scene.

Determining the location of a collision using the paths left by thrown objects

In some cases, the location of the collision can be determined by the direction of the tracks left on the road by objects thrown during the collision. Such tracks can be scratches and successively located holes on the road left by parts of the vehicle, motorcycles, bicycles or cargo that has fallen, as well as traces of dragging of the bodies of drivers or passengers who fell out of the vehicle at the moment of impact. In addition, traces of the movement of small objects remain at the scene of the incident, visible in the snow, soil, dirt, and dust.

First, the objects that are discarded move in a straight line from the point of their separation from the vehicle. Subsequently, depending on the configuration of the object and the nature of its movement along the road surface, a deviation from the original direction of movement may occur. With pure sliding, on a flat area, the movement of objects remains almost linear until they stop. When rolling while moving, the direction of movement may change as the speed decreases. Therefore, the location of a vehicle collision can be determined by the traces of thrown objects, if there are signs that these objects were moving in a straight line or the trajectory of their movement is visible.

To determine the location of the vehicle at the time of the collision, lines should be drawn along the tracks of thrown objects towards the probable location of the collision - a continuation of the direction of these tracks. The intersection of these lines corresponds to the point of impact (the place where objects that left marks were separated from the vehicle).

The more traces left by discarded objects are recorded, the more accurately it is possible to indicate the location of the collision, since it becomes possible to select the most informative traces, discarding those that could deviate from the direction of the collision site (for example, when rolling objects that left them while moving objects through irregularities, when the beginning of the trace is located at a large distance.

Determining the location of a collision by the location of objects separated from vehicles

It is impossible to determine the location of a vehicle collision by the location of any parts, since their movement after separation from the vehicle depends on many factors that cannot be ignored. The location of the maximum number of parts discarded during a collision can only approximately indicate the location of the collision. Moreover, if the location of the collision is determined by the width of the road, it is necessary to take into account all the circumstances that contributed to the unilateral displacement of the thrown parts in the transverse direction.

A fairly accurate location of the collision is determined by the location of the earth that crumbled from the lower parts of the vehicle at the moment of impact. During a collision, particles of earth crumble at high speed and fall onto the road almost in the place where the impact occurred.

The largest amount of earth is separated from deformed parts (the surfaces of the wings, mudguards, the bottom of the body), but if the car is heavily soiled, earth can also fall off from other areas. Therefore, it is important to determine not only from which vehicle the earth fell, but also from which parts of it. This allows you to more accurately indicate the location of the collision. In this case, it is necessary to take into account the boundaries of the areas where the smallest particles of earth and dust fall, since large particles can move further due to inertia.

The location of the collision can be determined by the location of the debris scattering areas. At the moment of impact, shards of glass and plastic parts fly in different directions. It is difficult to determine with sufficient accuracy the influence of all factors on the movement of debris, so it is possible to indicate the location of the impact only by the location of the dispersion area (especially if it is significant in size).

When determining the location of the collision by the location of the debris in the longitudinal direction, it should be taken into account that the debris in the direction of movement of the vehicle is scattered in the form of an ellipse, the nearest edge of which passes from the point of impact at a distance close to the place of their movement in the longitudinal direction during the free fall. This distance can be determined by the formula:

Where,

Va - vehicle speed at the moment of glass destruction, km/h;

h is the height of the location of the lower part of the destroyed glass, m.

As a rule, the smallest fragments lie closest to the point of impact; large fragments can travel much further, moving along the road surface after falling due to inertia.

Based on the location of small debris, the location of a collision is more accurately determined on a wet, muddy, dirt road or on a road with crushed stone surface, when the sliding of small debris along the road surface is difficult.

In case of oncoming collisions, the impact location in the longitudinal direction can be but an example but to determine based on the location of the far boundaries of the areas of scattering of glass fragments rejected from each of the vehicles that collided in the direction of its movement. With a similar nature of destruction of the same type of glass, the maximum range of debris being thrown when they move along the road surface is directly proportional to the square of the vehicle speed at the moment of collision (Fig. 1). Therefore, the collision site will be located at the following distance from the far boundary of the area where glass fragments are scattered from the first vehicle:

where S is the total distance between the far limits of the areas where glass fragments are scattered from oncoming vehicles;

V1, V2 - vehicle speed at the moment of collision.

Figure 1. Determining the location of a collision based on the dispersion range of glass fragments

When marking the far boundaries of areas where glass fragments are scattered, the possibility of error should be excluded, i.e. consider as discarded those debris that are carried out by the vehicle during its movement after a collision.
Based on the width of the road, the collision location can be indicated approximately in cases where the scattering area has a small width and the direction of the longitudinal axis of the scattering ellipse can be determined. It should be borne in mind the possible error in cases whereThe appearance of debris on the right and left of the direction of movement of the vehicle was not the same (for example, due to the ricochet of debris from the surface of the second vehicle).

Determining the location of the collision based on the final location of the vehicles

The direction of movement and the distance to which vehicles move from the point of collision depend on many circumstances - the speed and direction of movement of the vehicle, their masses, the nature of the interaction of contacting parts, resistance to movement, etc. Therefore, the analytical dependence of the coordinates of the vehicle collision location on the values ​​that determine these circumstances is very complex. Substituting formulas for quantities even with small errors can lead an expert to incorrect conclusions. It is almost impossible to determine the values ​​of these quantities with the required accuracy. It follows that based on data on the location of the vehicle after the incident, the location of the collision can only be indicated in some cases.

Figure 2. Determination of the collision location based on the final location of the vehicle.

1 - vehicle at the moment of collision; 2 - Vehicle after impact

When conducting examinations in cases, the question is often raised about which side of the roadway the collision occurred between vehicles moving in parallel directions. To solve this issue, it is necessary to accurately determine the lateral displacement of the vehicle from the collision site, which, in the absence of data on tracks on the road, can be determined by the location of the vehicle after the incident.

The location of a collision is most accurately determined in cases where, after the impact, the vehicles continue to be in contact (or diverge a small distance). The transverse displacement of the vehicle from the collision site then occurs due to their rotation around the center of gravity. The magnitude of the movement of the vehicle is approximately inversely proportional to the magnitude of the mass (or gravity), then to determine the lateral displacement from the point of collision, you can use the following formula:

Where,

Yk is the distance between the centers of gravity of the vehicle after the incident (final), measured in the transverse direction, m;

Yo- the distance between the centers of gravity of the vehicle at the time of the incident, measured in the transverse direction, m;

G1 andG2 - vehicle mass, kg.

Clarification of the collision location based on vehicle deformations

The study of damage sustained by a vehicle in a collision often allows one to determine the relative position at the time of the collision and the direction of impact. So, if the direction of movement and the location of one of the vehicles that collided at the moment of impact are determined, then the location of the second vehicle and the point at which their initial contact occurred is determined from the damage. In many cases, this makes it possible to determine which side of the road the collision occurred on.

If only the location of the vehicle after the accident is known, then the direction of the impact and the probable displacement of the vehicle after the collision can be determined from the damage. The location of a collision can be determined most accurately when the distances by which the vehicle has moved after the impact are insignificant.

In collisions that occur as a result of a sudden turn to the left of one of the vehicles, it is possible to determine the extreme right position of this vehicle at the moment of impact, based on the possibility of performing a maneuver when certain conditions clutch. In some cases, this makes it possible to find out on which side the collision occurred, if the deformation determines at what angle the impact was struck.

Characteristics of vehicle damage

In case of a vehicle collision, the main task of the expert study is to determine the mechanism of the collision, as well as to determine the location of the collision site of the vehicle relative to the boundaries of the roadway and the axle. When establishing the collision mechanism, damage to cars is studied (during transport and trace examination), and the main traces in establishing the location of the collision are those recorded in the accident diagram. All traces subject to expert analysis can be divided into two groups - these are traces in the form of damage on vehicles, and traces left by vehicles on other objects (roadways, road elements, etc.).

All traces in traceology are classified as:

Volumetric, having three dimensions (length, depth, width);

Surface, two-dimensional;

Visible to the naked eye;

Invisible;

Local:

Peripheral, located behind the zone of influence and formed by residual deformation;

Point and linear.

Positive and negative;

Layering and peeling.

In transport traceology, traces of vehicle collisions, the classification of which was given earlier, have 9 names adopted to describe damage during transport trace examinations:

1. A dent is damage of various shapes and sizes, characterized by depression of the trace-receiving surface and appears due to its residual deformation;

2. Burrs are sliding marks with raised pieces, parts of the track-receiving surface are formed when the hard surface of particles of one vehicle comes into contact with the less rigid surface of another vehicle.

3. Breakdown - through damage larger than 10 mm (used both when examining tires and to describe damage to parts of the vehicle).

4. Puncture - through damage up to 10 mm (used only when examining tires.

5. Scratch - shallow, superficial damage, the length of which is greater than the width and without removing the surface layer of the material (despite the paint coating).

6. Layering - associated with the process of trace formation and the transfer of material from one object to another.

7. Flaking - separation of particles, pieces of metal, and other substances from the surface of an object.

8. Scraping - the absence of pieces of the upper layer of trace-receiving material, caused by the action of a sharp cutting edge of another object.

9. Pressing - pressing the victim by a vehicle to another object or between parts of the vehicle itself (used in the production of complex automotive and forensic examinations).

The most informative signs indicating the location of the collision site include traces of vehicle movement before the collision. Such marks can be traces of braking, rolling, lateral shift, slipping, etc. At the same time, establishing the location of a collision using traces of vehicle movement requires research into both the nature of their location and their belonging to a specific car and even a wheel. So, if the diagram shows a braking trace on the roadway, which was first directed straight and then sharply deviated to the side, then the location of the deviation of the traces indicates that while the car was moving, it was influenced by a shock load, which led to the deviation car movement. The occurrence of a shock load is a fact of interaction between vehicles during a collision. Therefore, when determining the location of a collision, both the location of the change in direction of the braking marks and the location of the location of the primary contact in the vehicle itself, which is established when determining the mechanism of the collision, are taken into account.

Lateral shear marks also indicate that their formation is caused by a collision between vehicles, and by establishing that certain marks belong to specific wheels of the collision mechanism, the location of the collision is determined.

Trace information indicating the location of the collision includes traces in the form of scree of earth or dirt from the lower parts of the vehicle during a collision, as well as traces in the form of scratches, burrs, potholes on the road left by deformed parts of the vehicle after the collision. In this case, when establishing the location of the collision, it is necessary to first determine which part and which vehicle left these marks on the road. This is established during an expert review of damaged cars. This also takes into account the mechanism of the collision, that is, the possibility of moving the car that left a mark on the road from the immediate location of the collision. Most often, in an accident there is only a scattering of glass fragments from small parts from cars, which, moreover, occupies both lanes of traffic. In accordance with methodological recommendations, a scattering of glass fragments and other small parts of cars separated during their collision indicate only the area in which the collision was located, and not the place itself. Therefore, determining the coordinates of the collision site by the location of the scree of glass fragments, as well as bulk cargo, in this case can be done by the method of excluding territories. The essence of this method is that the scree zone is first divided into two sections and, taking into account the study of the collision mechanism, the final position of the vehicle, as well as other traces of the vehicle’s movement, do not independently carry informative signs of the location of the collision site, one of the sections is excluded. Then the remaining area is again divided into two zones, etc.

When applying this method, it is advisable to use full-scale modeling at the accident site or planar modeling in a large-scale diagram.

When installing a vehicle collision mechanism, as noted, trace information is available in the form of damage on the vehicles themselves. At the same time, in transport traceology there is no distinction between objects that form traces and those that perceive traces, because any area of ​​damage is simultaneously both trace-forming and trace-receiving. In expert practice, establishing the collision mechanism based on damage to cars consists of the following stages of research: separate research, comparative research and natural comparison of vehicles. Moreover, if the first two stages are mandatory, without which installation of the collision mechanism is impossible, then the third stage cannot always be carried out, and the impossibility of its implementation does not depend on the expert. In this case, the expert must conduct a simulation based on the first two stages of the study. It is necessary to point out another type of trace information examined by experts during complex automotive and forensic examinations. These marks include marks on the victim’s clothing, as well as marks in the form of bodily injuries on the victim’s body. The study of such traces in conjunction with traces on the vehicle makes it possible to establish the mechanism of the collision of a car with a pedestrian.

The most difficult studies should be considered to be studies to determine the identity of who was driving the car at the time of the accident. In this case, traces on the road, traces on the vehicle, as well as traces on the bodies of people who were in the car at the time of the incident are examined.

Analyzing the above, it should be pointed out that the assessment of trace information in each specific case is individual and cannot be a once and for all established method, but requires an expert abstract thinking, covering the entire gamut of traces, as well as taking into account the described evaluative features in the traces.

Application

Examples of characteristic relative position vehicles at the moment of collision (depending on the angle between their speed vectors):
1. Longitudinal, counter, straight, blocking, central, front.

2. Longitudinal, passing, straight, blocking, central, rear.

3. Longitudinal, counter, direct, tangent, eccentric, lateral.

4. Longitudinal, associated, parallel, tangent, eccentric, lateral.

5. Cross, transverse, perpendicular, blocking, central, left.

6. Cross, associated, oblique, sliding, eccentric, left.

7. Cross, counter, oblique, sliding, eccentric, left.

The location of vehicle damage from contact with each other makes it possible to determine their relative position at the time of the collision and to clarify the location of the collision if the location and direction of movement of one of them at the time of the collision are established.

Sometimes the angle is determined from photographs of damaged vehicles. This method gives good results only when pictures of different sides of the car are taken at right angles from the same distance. Due to the fact that measuring vehicle deformation and taking photographs to determine the collision angle requires certain skills and knowledge, it is advisable to carry them out with the participation of experts.

The direction of deformation, which determines the direction of the impact, makes it possible to determine the possible displacement of the vehicle from the collision site, and by its location after the incident, to clarify the location of the collision.

The nature of the deformations makes it possible to establish the collision angle of the vehicle and, by calculation, determine the value of the interval between the moving parallel courses of the vehicle before turning one of them into the lane of the other (based on the maximum adhesion radius of the turn). This allows you to clarify the location of the collision based on the width of the lane.

Rice. 4. Types of location of vehicles at the time of an accident.

The location of the damage on the lower parts of the vehicle, which left tracks on the road during a collision, makes it possible to clarify the position of the vehicle along the width of its lane when these tracks were formed at the collision site.

Examination of damage to painted and metal parts makes it possible to determine the direction of movement of the colliding vehicles. Marks on the surface of a damaged car that are wider than deep and longer than wide are called scratches. Scratches run parallel to the damaged surface. They have a small depth and width at the beginning, widening and deepening towards the end. If the primer is damaged along with the paintwork, it peels off in the form of wide, drop-shaped scratches, 2-4 mm long.

Damage that is deeper than wide is called nicks or dents. The depth of the scratch usually increases from its beginning to its end, which makes it possible to determine the direction of movement of the scratched object. Sharp burrs often remain on the surface of the scratch, which are bent in the same direction in which the scratched object moved. For a car that was moving slower, the scratch marks are directed from the back to the front, and for the overtaking car, the scratch marks are directed towards the front. the opposite side.

In the event of an oncoming collision, the speeds of the vehicles cancel each other out. If their mass and speed were the same, then they stop near the collision site. If the masses and speeds were different, then the car moving at a lower speed or lighter is thrown back. If the driver of a truck at the time of an accident does not take his foot off the gas pedal and, confused, continues to press it, then the truck can drag an oncoming passenger car for quite some time. long distance from the collision site.

According to statistics, the most common type of traffic accident is collision. In this regard, we propose to consider in detail the modern classification of types of vehicle collisions, which meets the needs of transport-trasological examination, which should contribute to the systematization of methods and the most complete development of methods for expert research of the circumstances that determine the mechanism of vehicle collisions.

The main requirement for any classification, in addition to compliance with its purpose for which it is carried out, is a clear formulation of classification criteria, ensuring full coverage of all members of the system, eliminating the possibility of homogeneous members into different classification groups and heterogeneous - into the same group.

The fundamental components of this classification are concepts systematized and presented by N. M. Christie together with a group of authors.

Classification features that determine the mechanism of vehicle collisions are divided into two main groups: features that are common to a collision of two vehicles as a whole, and features that relate separately to each of them, which may not coincide.

TO common features belong to the following.

I. Movement of one vehicle in the transverse direction relative to the lane of another as they approach each other (classification according to the direction of movement of the vehicle). The sign is determined by the value of the collision angle, which can be determined by the wheel tracks of both vehicles before the collision, by the location of the vehicle and the traces of their movement after the incident, by the direction of throwing objects separated from them (glass fragments, etc.), by the deformations obtained during the collision.

• 1) longitudinal - a collision without a relative displacement of the vehicle in the transverse direction, i.e. when moving in parallel courses (angle + is 0 or 180°);
• 2) cross - a collision when the vehicle moves on non-parallel courses, i.e. when one of them shifted transversely towards the lane of the other (the angle is not equal to 0.180°).

II. Movement of vehicles in the longitudinal direction in relation to each other (classification according to the nature of the mutual approach of the vehicles). The sign is also determined by the magnitude of the collision angle.

Based on this criterion, collisions are divided into the following three groups:

• 1) oncoming - a collision in which the projection of the speed vector of one vehicle onto the speed direction of the other is opposite to this direction; The vehicles approached each other with deviation towards each other (angle > 90°,
• 2) passing - a collision in which the projection of the speed vector of one vehicle onto the speed direction of the other coincides with this direction; The vehicles approached each other, moving with deviation in one direction (angle 270°);
• 3) transverse - a collision in which the projection of the speed vector of one vehicle onto the speed direction of the other is zero (the angle is 90°, 270°).

If the angle differs so little from zero or from 90° that the research methods used do not allow one to establish this deviation, and if the possible deviation does not have a significant effect on the collision mechanism, then the latter can be defined as longitudinal or transverse, respectively.

III. Relative location of the directions of the longitudinal axes: the vehicle at the moment of the collision. The sign is determined by the angle of relative position of the longitudinal axes, which is established on the basis of traceological studies of traces and damage in places of direct contact of the vehicle during a collision. In some cases, the angle may be set based on the wheel tracks ahead of the collision.

Based on this criterion, collisions are divided into two groups:

• 1) direct - a collision when the longitudinal or transverse axis of one vehicle and the longitudinal axis of the other are parallel (the angle is 0.90°);
• 2) oblique - a collision in which the longitudinal axes of the vehicle were located in relation to each other under acute angle(angle is not equal to 0.90°).

IV. The nature of the interaction of contacting parts of the vehicle during a collision. The sign is determined by deformations and marks on the contact areas. Based on this criterion, vehicle collisions are divided into three groups:

1) blocking - a collision in which during contact relative speed By the time the deformations are completed, the vehicle in the contact area is reduced to zero (the forward speeds of the vehicle in this area are equalized). In such a collision, in addition to dynamic ones, static marks (prints) remain on the contact areas.

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

The turning angle during contact is, as a rule, small if the relative movement of the vehicle during mutual contact is insignificant, at low speed of approach and blocking collisions, as well as at slight eccentricity of the impact;

2) sliding - a collision in which, during the contacting process, slipping occurs between the contacted areas due to the fact that until the moment the vehicle leaves contact with each other, their speeds of movement are not equalized. In this case, only dynamic traces remain on the contacted areas.

In sliding collisions, when the movement of the vehicle during mutual contact is large, and during a sharply eccentric impact, the angle of rotation by the time the vehicle leaves contact with each other can be significant. The influence of the type of vehicle on its turn during a collision is associated with the mass of the vehicle and its dimensions: the greater the mass and dimensions (and, consequently, the moment of inertia relative to the center of gravity), the smaller the angle of turn of the vehicle by the time it leaves contact with another vehicle;

3) tangential - a collision in which, due to the small amount of overlap of the contacting parts of the vehicle, they receive only minor damage and continue to move in the same directions (with a slight deviation and reduction in speed). In such a collision, horizontal traces (scratches, rubbing marks) remain in the contact areas. An accident is not a consequence of interaction forces upon impact, but of subsequent collision with other obstacles.

The features that characterize the collision mechanism separately for each of the two vehicles also include the following.

V. The direction of the vector of the resultant of the impact impulse vectors (direction of the collision line) in relation to the location of the center of gravity of the given vehicle, which determines the nature of its movement after the collision (with or without a turn). Based on this criterion, collisions are divided into two groups:

• 1) central - when the direction of the collision line passes through the center of gravity of the vehicle;
• 2) eccentric - when the line of collision passes at a certain distance from the center of gravity, to the right (right eccentric) or to the left (left eccentric) of it.

VI. The location along the perimeter of the vehicle of the area that was in contact during the impact (classification according to the location of the impact). The sign (along with the relative position angle a 0) determines the relative position of the vehicle at the moment of the collision. Based on this criterion, collisions are divided into the following groups:

• 1) front (frontal) - a collision in which traces of direct contact upon impact with another vehicle are located in the front parts;
• 2) front corner right and 3) front corner left collision, in which contact marks are located on the front and adjacent sides of the vehicle;
• 4) lateral right and 5) lateral left - a collision in which the blow was struck in side TS;
• 6) rear corner right and 7) rear corner left - a collision in which traces of direct contact are located on the rear and adjacent side parts of the vehicle;
• 8) rear - a collision in which the contact marks caused by the impact are located on the rear parts of the vehicle.

This type of collision classification system allows us to cover all possible types of collisions between two vehicles and determine the characteristics of any collision.

A road traffic accident is a complex cognitive object of expert research. Based on the above classification, it is obvious that the system of signs of a particular collision in its totality appears to be complex process mechanism of an accident. In this regard, we considered it necessary to include in this classification two criteria that are “final” in assessing the collision mechanism - a typical (simple) collision and an atypical (complex) collision.

A typical collision is an accident in which common, frequently repeated signs predominate and which is characterized by the obviousness of the incident, the presence of all cars involved in the accident, and a small number of vehicles.

An atypical collision is an accident in which a significant number of vehicles are involved, with the participation of a pedestrian(s), the process of the incident is multi-stage, non-obvious in nature, the recognition of which requires high qualifications and special knowledge in several scientific fields. Often the complexity of an accident is expressed in the fact that the vehicle that caused the collision fled the scene.

An analysis of the literature shows that an incident (crime) is considered to be unobvious if at the time of initiation of a criminal case the person who committed it is unknown, and to identify and detain this person it is necessary to carry out investigative actions and operational search activities.

A traffic accident is complex when it is associated with the construction of several mental probabilistic models. The complexity of an accident depends on the number of accidents structural elements, connections between them. If to recognize an accident it is enough to build an unambiguous mental model of it, then what kind of situation will be simple.

During an accident, marks and damage of a very diverse nature are formed. At the same time, a certain pattern of their display can be traced, due to the mechanism of the road traffic accident.

• Christie N. M., Tishin V. S. Transport and traceological examination in cases of road traffic accidents. Diagnostic studies. Part 2: methodical. manual for experts, investigators and judges / edited by Yu. G. Korukhova. M.: Expert Library, 2006. pp. 3-7.
• Belyaev M.V., Bushuev V.V., Demin K.V. Traceology and traceability examination. Private teaching methods in specialty 031003.65 Forensic examination: educational and methodological. allowance. M.: Publishing house of Moscow University of the Ministry of Internal Affairs of Russia, 2013. P. 96-102.

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 the resolution of any issue requires knowledge in several areas scientific knowledge, 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, vehicles stop at the collision site or bounce off 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 large number road traffic 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 the traffic 20-30%;
• - due to a technical malfunction of the car 10-20%” Konoplyanko V.I. Organization and security 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 may be scattered over a relatively large area. 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 drove out to the intersection with 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.

The main types of road accidents that require ASR are collisions, which are divided into:

windshield- vehicle collision in oncoming traffic;

lateral- collision of a vehicle with the side of another vehicle;

tangent- collision of a vehicle with its sides during oncoming traffic or movement in one direction;

capsize- an incident in which a moving vehicle overturned;

hitting a standing vehicle- an incident in which a moving vehicle collided with a stationary vehicle, as well as a trailer or semi-trailer;

hitting an obstacle- an incident in which the vehicle ran over or hit a stationary object (bridge support, pole, tree, fence, etc.).

Special types of accidents that require ASR

Special types of accidents- Road accidents complicated by dangerous factors requiring special training rescuers or attracting additional forces and resources.
Accident with vehicle falling into water- Road accidents in which vehicles for some reason fall into rivers, lakes, the sea, fall through ice, etc.
Accident with vehicle falling from steep slopes- Accidents in which vehicles, for some reason, fall off steep slopes and, when falling, usually roll over several times, hitting rock ledges, and fly 100–150 m or more. Sometimes vehicles explode. The vehicles themselves turn into a pile of twisted metal.
Accident on a railway section- road accidents in which: a vehicle collides with a moving or stationary train at a railway crossing or on a section of the railway not intended for crossing; A vehicle collides with another vehicle at a railway crossing; a rolling stock collides with a vehicle at a railway crossing or on a section of the railway not intended for crossing.
Accident involving a tram (trolleybus)- Accidents in which a tram (trolleybus) collided (ran over) into another vehicle, or as a result of power wires breaking and falling on the vehicle, or a tram derailing and overturning, the vehicle or people were injured.
Road accident with fire– Road accident, accompanied by fire of emergency vehicles and the cargo they transport.
Vehicle falling under a rubble- An accident in which a vehicle with people as a result of natural or man-made phenomena was caught in an avalanche, mudflow, landslide, rockfall, etc.
Accident in a tunnel (overpass)- Road accidents complicated by the specifics of a limited space, which makes it difficult to access the accident site, carry out emergency response and evacuate victims.
Accident with a vehicle carrying dangerous goods- An accident with a vehicle carrying cargo falling under the category of dangerous, as a result of which there was a leakage (ejection, fire, etc.) or there is a danger of such a situation, including:
- an accident with a vehicle transporting flammable liquids (FL) or flammable liquids, which resulted in a spill or leak;
- an accident with a vehicle transporting hazardous chemical substances (HAS), which resulted in a spill or leak;
- An accident with a vehicle transporting radiation hazardous substances (RS), as a result of which a spill or leak occurred, resulting in contamination by them. environment;
- an accident with a vehicle transporting biologically hazardous substances (BH), as a result of which there was a spill or leakage, resulting in contamination of the environment;
- Road accident with a vehicle carrying explosives and explosive objects, in which there is a threat of detonation of explosives and high explosives due to their movement, mechanical impact on them or heating (combustion).