The behavior of minors and road safety – case study of Poland

2.1 Analysis of road accidents

One in four deaths in Poland from road traffic accidents is due to external causes. There were 2,909 deaths in road traffic accidents that occurred in 2019 (7.7 deaths per 100,000 residents). There were 1.0 road fatalities per 10,000 registered vehicles (compared to 4.5 in 2000). According to 2019 fatality analyses, rural roads were the most fatal roads in Poland, accounting for 57% of all road fatalities [15]. Inadequate speed for road conditions and failure to yield are the main causes of accidents. A significant number of pedestrian fatalities and/or accidents were caused by road users driving under the influence [7].

According to statistics [15], 207 drivers and 8 passengers traveling on single-track vehicles were killed in 2021 in Poland. In the analyzed year, there were 2,050 accidents involving motorcyclists. Taking into account the statistics for 2020, there was a decrease in the number of accidents: −25 (−1.2%), and the number of people killed, −29 (−11.9%), with a slight increase in the number of injuries by 5 (+0.3%).

In road traffic accidents, the risk of death is strongly related to the age of the victims; this is particularly evident among novice drivers. According to WHO data, one in three accidents (37.31%) involves people aged 25–49 [38]. Drivers aged 18–24 cause the most accidents, according to the data from the Polish police and surveys conducted by insurance companies. It was reported that 18.5% of all accidents caused by drivers occurred in 2019. Exceeding the speed limit in traffic was the main cause of accidents. Unfortunately, it raises the concern that these accidents were associated with the highest fatality rate, i.e., 53.2% [40]. The problem is, therefore, significant in terms of reducing mortality from this cause among young people [7].

Young drivers are, therefore, at high risk of dying in a road traffic accident. For example, in Germany in 2017, road traffic accident deaths in the 15–49 age group accounted for 41.6% of the total number of deaths from this cause (60.5% in 1990). During the same analyzed period in France, this value was 50.1% (51.3% in 1990), and in Italy, 41.7% (52.9% in 1990) [39]. The corresponding mortality factor in Poland, however, was higher than in most EU countries.

With regard to Poland, it can be observed that a significant number of victims were schoolchildren who suddenly ran out onto the road in front of an oncoming vehicle. The absolute majority of traffic incidents occurred in urban areas or built-up areas. The fact that many roads in Poland do not have a sidewalk or paved shoulder contributes to an increased risk of accidents. Statistics from the Polish Police further show that a large number of accidents involving children occur on the home–school–home route [40,41].

It should be added that drivers under the age of 30 are the most likely to cause accidents involving children [30]; moreover, they are the perpetrators of accidents, accounting for 18% of the total number of fatalities in road traffic accidents [18,20,21,22,23].

Further statistical data on accidents is based on the Police Headquarters Report, Road accidents in Poland in 2021 [15]. They show that in 2021, children aged 7–14 were the perpetrators of 250 road accidents (an increase of 49 accidents compared to 2020), three children died in them (a decrease of 2 people compared to 2020), and 257 were injured (an increase of 49 injuries compared to 2020). The above figures are illustrated in Table 1.

At risk of traffic accidents are minors aged 15–17. In 2021, there were 1,775 accidents involving children (0–14 years old), with 50 people killed and 1,832 injured. This age group had the highest number of passenger casualties. Quantitative statistics of accidents involving children aged 0–6 and 7–14 are illustrated in Table 2 and Figure 1.

Figure 1

Child road accident victims in 2019–2021 [15].

A relatively large number of accidents are caused by minor traffic participants aged 0–14. They were the perpetrators of 494 accidents, which resulted in 6 deaths and 504 injuries, as illustrated in Table 3.

School-age children, who were pedestrians and car passengers, prevailed among victims of road traffic accidents; however, cyclists were also a major risk group. It should be added that analysis by the Polish Police Headquarters shows that the rule of yielding is not respected by half of the child cyclists or motorcyclists involved in accidents. Thus, it can be inferred that this traffic rule is not understood properly [27].

The group of children aged 15–17 is also particularly vulnerable. This is because they are individuals who consciously participate in traffic. They move on the road, both as pedestrians and as cyclists and moped drivers [6,8,9]. In contrast, among minors aged 0–6, accident victims are primarily car passengers, pedestrians, and only a small group of cyclists [8,9,10].

It should be added that the experience in road safety work in Poland is relatively short. The number of traffic fatalities increased in the early 1990s to 8,000 per year. The reason for this was the lack of systemic road safety measures in Poland. Therefore, the government reacted accordingly and set up special road safety bodies. Among other things, the development of road safety programs was commissioned. However, when analyzing the above data, especially with regard to minors and the young, it seems that the introduction of a road safety policy has not achieved the expected solutions. This is because road traffic incidents are not considered a serious problem. As a result, they are disregarded in programs, policy solutions, and institutions remain ineffective due to a sense of collective responsibility for road safety problems [42].

2.2 Legal status regulating the presence of minors on the road in Poland

The basic rules of road traffic were laid down in the Vienna Convention on Road Traffic in 1968 [43]. However, it has not been ratified by all countries.

In Poland, the basic, most important legal act that regulates traffic issues is the “Traffic Law.” It was introduced on June 20, 1997, through an act with the force of law [41]. Since then, it has been amended several times, allowing the legislation to be adapted to the current economic, political, and legal situation. This law defines the rules that apply to all road traffic participants in four basic areas:

1. The rules of traffic on public roads, in residential zones, and in traffic zones.

2. The rules and conditions for the admission of vehicles to this traffic, as well as the activities of the competent authorities and entities in this regard.

3. The requirements for traffic participants other than vehicle drivers.

4. The rules and conditions for traffic control.

In this law, several provisions regulate the rights and obligations related to the participation in traffic of special road users, including minors:

• The first criterion is the age limit, i.e., age 7. In Article 43, it is stipulated that only children who are at least 7 years old can fully independently travel on public roads on foot (i.e., walk and/or return from school independently, for example). Until then, they are to remain supervised by a person who is at least 10 years old (this could be an older sibling, for example). This also applies to the sidewalk, which is part of the road, as well as roadsides or neighborhood streets. It is irrelevant whether the minor behaves appropriately or in a way that endangers safety on the road. However, the provision above does not apply to residential zones and roads intended exclusively for pedestrian traffic but is closed to vehicle traffic (such as pedestrian streets) – in that case, children under 7 years of age can also move independently [41].

• In addition, attention should also be paid to the issues related to traveling after dusk on the road outside built-up areas. In such situations, in line with Article 11 of the “Traffic Law,” every pedestrian – regardless of age (including children) – is obliged to use reflective elements in a manner visible to other traffic participants. Reflectors must also be worn by other road users, namely cyclists, scooters, motorcycle drivers, or people walking strollers by the side of the road. Failure to comply with this regulation may result in a fine.

• Other important issues are found in Article 39, which describes the rules for drivers and passenger vehicles on the road in a detailed manner. In addition to the general issue of the obligation to use seat belts, specific rules are also included; the legislator has introduced a number of regulations in this regard. In the case of transporting children in a vehicle, the child’s height, rather than age, is the most important criterion.

Thus, paragraph 3, Art. 39 of the analyzed law states that in vehicles of categories:

• M1 (passenger transport vehicles with up to eight seats excluding the driver’s seat);

• N1 (cargo transport vehicles with a maximum weight up to 3.5 tons);

• N2 (cargo transport vehicles with a maximum weight over 3.5 tons, but not exceeding 12 tons);

• N3 (cargo transport vehicles with a maximum gross weight exceeding 12 tons) that are equipped with seat belts or other child-support devices, a child with a height under 150 cm should be transported in a safety seat or other child restraint device. These devices must be adapted to the weight and height of the child, and they must comply with the technical conditions set forth in the European Union regulations or the UN ECE regulations.

  In paragraph 3b, there are some exceptions to this rule; in fact, in vehicles of categories:

• M1, N1, N2, and N3, a child with a height of at least 135 cm, who will be secured by a seat belt, provided that the child’s height and weight do not allow the use of a safety seat or other restraint device, may be transported in the rear seat of the vehicle.

In turn, paragraph 3c of Article 39 includes a provision that allows a third child aged 3 or younger to be transported in the rear seat of M1 and N1 category vehicles without a child safety seat, secured only by a seat belt, when it is not possible to install a third safety seat in the rear seat [41].

The provisions discussed above do not apply to the transportation of a child in a taxi, special sanitary transport, a vehicle of the Police, Border Guard, or municipal (city) police, or a child who cannot be transported in a child safety seat or other child restraint device for health reasons (however, a special medical certificate is then required).

At the same time, it should be added that the various provisions on the carriage of children are scattered in several different parts of the Road Traffic Law, which can make it difficult to find the relevant provision more than once. Attention should also be paid to the provisions on the use of bicycles, as mentioned in Article 33. Paragraph 2 of this article states that a child up to the age of 7 may be carried on a bicycle, provided that it is placed on an additional saddle that ensures a safe ride [46]. After the age of 7, a child can already ride a bicycle independently but is still basically treated as a pedestrian. This means that it can use the sidewalk pedestrian crossings and ride on the roadway only on its left side. At the age of 10, a child can obtain a bicycle card and ride on the road independently. On the other hand, a moped can be driven by a minor who has obtained the necessary qualifications (moped card) and turned 13 years old. A person who has reached the age of 17 can only drive a bicycle cart, a multi-bike or carry others on a bicycle.

A driving license for category AM can be obtained by a person at the age of 14 and with the consent of parents or guardians, which allows them to drive a moped or light quad with a maximum speed of 45 km/h with an unladen weight of 350 kg. Category A1 driver’s license can be obtained by a person at the age of 16, having written parental consent, and entitles them to drive motorcycles with a capacity of up to 125 cc and an output of up to 11 kW, as well as three-wheeled motorcycles with an output of up to 15 kW [41].

Moreover, on May 20, 2021, new regulations introduced by an amendment to the Traffic Law came into effect, legally regulating, among other things, e-scooters and personal transportation devices. They also significantly change the rules of priority for pedestrians traveling within pedestrian crossings. According to the newly established definitions, an electric scooter means an electrically-powered, two-axle vehicle with handle-bars, without a seat or pedals, structurally designed to be moved exclusively by the rider on the vehicle. In turn, a personal transportation device is defined as an electrically powered vehicle, excluding an electric scooter, without a seat and pedals, structurally designed to be moved exclusively by the driver on the vehicle.

Hence, with the expansion of the catalog of mobility devices and vehicles, each has been strictly defined in terms of the rules of use, as well as the rights and obligations incumbent on its users. The driver of an electric scooter is obliged to use a bike path or a cycling lane if they are designated for the direction. On the other hand, in the absence of a designated bike path or cycling lane, the driver of an electric scooter is obliged to use the roadway. Scooter drivers may use the sidewalk or pedestrian way only if the sidewalk is arranged along the roadway and at the same time there is a lack of a separated bike path or a cycling lane. It is also worth noting that the permissible speed at which electric scooters and personal transport devices can move is 20 km/h .

Specifically referring to persons under the age of 18, i.e., underage road users, the document stating the right to drive an electric scooter or personal transport device is a bi-cycle card or a driver’s license for categories AM, A1, B1, or T. It should be added that children under the age of 10 are prohibited from driving an electric scooter or personal transport device on the road. This is possible only in a residential zone and only under the supervision of an adult.

To reinforce selected rules for the use of vehicles and other means of transportation, and in particular to highlight prohibited behavior on the road, Article 45 of the “Traffic Law” under consideration – with respect to underage traffic participants – states that the driver of a vehicle may not transport a child in a safety seat in the front seat of a vehicle equipped with an active passenger airbag, facing rearward. In addition, it is forbidden to carry a child under the age of 3 in vehicles of categories M1, N1, N2, and N3, not equipped with seat belts and a safety seat, as well as to carry a child less than 150 cm in height in the front seat of a motor vehicle, except in a child safety seat [41].

All of the principles analyzed above can be found in the main legal act regulating traffic issues. However, certain issues related to children as users of roads and various means of transportation can also be found in other legal acts. As an example, the Law of May 20, 1971 (as amended) – the Code of Offenses [44]. Article 89 of this law stipulates that a parent or other person obligated to care for a child who allows a child under the age of 7 to move independently on the road commits an offense punishable by a fine.

Summarizing the above, it should be said that the transportation of children and their independent use of various means of transportation (such as a bicycle, moped, or electric scooter, for example), as well as their use of sidewalks, roadsides, pedestrian crossings, or neighborhood streets as pedestrians, are subject to a variety of regulations. It follows that both children and their guardians should always behave and move in accordance with traffic regulations. Compliance with these rules improves traffic safety and often avoids various accidents or minimizes their consequences.

Simultaneously, it should be remembered that reckless and irresponsible behavior on the road very often has its source in the lack of knowledge of traffic regulations, which should be a premise for authorities at various levels to implement appropriate information and education measures. The behavior of children’s parents or guardians, who should also ensure that their children have adequate knowledge of traffic regulations, is also important. They should also help their children learn how to drive on the road independently. Among other things, it is recommended that parents of children who are going to walk to and from school on their own should walk this route several times with their guardians. The idea is to make sure that children are aware of possible dangers and of their responsibilities as pedestrians right from the start.

4.1 Case study 1

The incident took place in February at around 1 p.m. on one of the streets in the county town. There was no wind or fog during the incident, and the ambient temperature was about 13°C. The road at the accident site was straight and flat, with a two-way asphalt roadway, which was 7.2 m wide. Adjacent to the roadway, there were dirt shoulders 2.9 and 3.2 m wide on both sides. Moments before the accident occurred, an Autosan bus delivering children from school stopped on the aforementioned roadway, from which several children alighted. The bus then drove off in the direction in which it was traveling. At that time, from the opposite direction of the bus came the driver of a Daewoo Tico, who, after passing the bus, noticed a 7-year-old girl running from the left to the right side of the road in front of his vehicle. There was an impact of the left front corner of the vehicle being braked into the right side of the child’s body. As a result of the injuries sustained, the girl died a few 6 days after the accident occurred. The Daewoo Tico car sustained damage to the left front corner of the body and windshield, which can be seen in Figure 2 [39].

Figure 2

Damage to the Daewoo Tico car [47].

As a result of the reconstruction of the course of the incident, conducted on the basis of the vehicle’s braking traces, its speed was determined to be 67.0 km/h , with 50 km/h , allowed for the scene. The speed of the vehicle was determined from the following relationship:

where V u = 12.8 m / s is the speed of the Daewoo Tico car at the time the pedestrian was hit:

The speed of the Daewoo Tico car was reduced during braking after hitting the pedestrian,

• 25 kg – the mass of the pedestrian at the time of the collision,

• 691 kg – the mass of the Tico car with the driver at the time of the collision,

• a h = 0.7 × 9.81 = 6.8 m / s 2 , – average braking deceleration on dry asphalt,

• 10.0 m – the length of the vehicle’s braking traces after the collision with the pedestrian [36].

The summary of data is shown in Table 4.

A spatial and temporal analysis of the course of the accident showed that if the driver of the Daewoo had been driving at the administratively permissible speed and had reacted with braking to the child running into the roadway, he would have stopped the vehicle in front of the child’s path. From the evaluation of the behavior of the participants in the accident, it was clear that the danger that contributed to the occurrence of the tragic accident was caused by the behavior of the 7-year-old girl, who left without sufficient adult supervision, ran across the roadway directly in front of the moving passenger car. The driver of the Daewoo Tico also contributed to the accident by driving at a prohibited speed, thereby having no opportunity to avoid the accident.

In the analyzed incident, the reconstruction of the course of the accident was aimed at determining the speed of the car at the time of hitting the child and the speed of the vehicle at the time when the road hazard arose. Knowing the above-mentioned parameters enabled determination of the details of the incident and the extent of the responsibility of the participants in the accident for its occurrence, and allowed indicating the correctness of the defensive maneuvers taken by the driver of the car to avoid the accident. Equation (3) – the balance of motion of the Daewoo Tico car being braked in a collision with a pedestrian – determines the speed of the car at the time when the driver began defensive maneuvers (braking) in connection with the emergence of a road hazard. In the example analyzed, this could have been the beginning of the child’s movement in the direction of the car’s path. The above-mentioned energy balance took into account the following:

• The speed of the vehicle reduced before hitting the pedestrian Equation (3).

• The speed of the vehicle reduced when hitting the child, Equation (2).

• The speed of the vehicle reduced during braking after hitting the child over a 12 m distance to where the car stopped, as V h 2 = 2 × 6.8 × 12 = 12.77 m / s , which was entered into Equation (3).

• The equation balancing the initial speed V _s, the speed of the car reduced during the build-up of braking deceleration was additionally taken into account:

for half the deceleration build-up time of t = 0.3 s for hydraulically applied brakes.

The knowledge acquired in the course of reconstructing the course of the accident indicates the following:

1. at the scene of the accident, the driver of the car exceeded the administratively permissible speed, i.e., 50 km / h , by 17 km / h ;

2. the collision speed, i.e., the speed when the child was hit, was 12.0 m / s ( 43.49 km / h ) , which was decisive for the consequences of the accident;

3. the driver’s exceeding the speed limit did not allow the driver to avoid the accident despite braking;

4. the driver’s exceeding of the speed limit made him unable to avoid the accident, as shown in the analysis below.

5. Under real conditions, the driver was at a distance S _o away from the point of collision with the child.

For: S _o = 10 m + 1.2 × 18.6 = 32.32 m for the average statistical reaction time of the driver and the accumulation of braking delay t _rk = 1.2 s. In the situation of driving at the speed limit of 50 km / h ( 13.89 m / s ), the driver would be able to stop the car on the road section S _z50 as follows:

Given the shorter stopping distance of the car traveling at 50 km / h , i.e., 30.85 m, then the distance the driver was at when he proceeded to brake, i.e., 32.32 m, the driver driving at 50 km / h and braking, as under real conditions, would have stopped the vehicle before the place where the child was hit.

It follows from the above analysis that the danger, decisive for the occurrence of the accident, was created by the child, and the driver contributed to the accident by driving at a prohibited speed.

4.2 Case study 2

The accident occurred in April 2016 at around 5 p.m. in a built-up area. The road at the site of the accident was flat and straight, with an asphalt two-way roadway 5.0 m wide. Adjacent to the roadway, there were shoulders strewn with gravel on both sides, each 0.6 m wide. At the time of the accident, it was sunny, there was no fog, and the ambient temperature was 15°C. The incident involved a 4-year-old girl running across the roadway and being hit by a moving Toyota Yaris car driven by a woman. The scene revealed brake marks of the Toyota vehicle on the road before and after hitting the underage pedestrian [36].

Reconstruction of the course of the accident showed that the driver of the Toyota was traveling at a speed of about 85.0 km / h , with the speed limit for the accident site being 50 km / h .

The speed of the vehicle was determined by the following relationship:

where

The speed of the Toyota car reduced during braking on a 7.0 m-long section on dry asphalt and the left front wheel partially on gravel ground, with an average tire-to-ground adhesion coefficient of 0.55:

• 12.0 m – the length of the braking traces when the right wheels of the vehicle were braked on a gravel and partially ground surface with a traction coefficient of 0.5,

• 31.0 m – length of braking tracks on dry asphalt with a traction coefficient of 0.6.

  In the relationship determining V _s, i.e., the initial speed of the Toyota car, the components of the speed of the car being braked while moving on the ground with different coefficients of traction of the vehicle’s wheels to the ground were taken into account. In equation (8) below

  (8) V k = 2 × 0.55 × 9.81 × 7.0 = 6.05 m / s .

• The reduction in vehicle speed on a 7.0 m-long road section with an averaged coefficient of adhesion of tires to various substrates of μ = 0.55 was determined.

The other components of the car’s speed V _s include the car’s deceleration on a gravel and dirt road with a length of 12 m, with an average wheel traction coefficient of μ = 0.5, and the car’s deceleration on an asphalt road with a length of 31 m and a traction coefficient of μ = 0.6. At this point, it should be added that the car’s braking deceleration is defined as a h × µ × 9.81 m / s 2 . The reconstruction of the accident course carried out above enabled us to determine the braking motion of the Toyota car for different types of road surfaces. The calculated speed of the Toyota car under the conditions of a built-up area indicates that the driver significantly exceeded the speed limit of 50 km / h . The summary of data is shown in Table 5.

Speeding by the driver of the vehicle demonstrated a causal relationship with the incident. On the other hand, the danger that determined the occurrence of the accident was created by a 4-year-old child who, deprived of sufficient care from authorized persons, ran across the roadway directly in front of a moving Toyota Yaris car. The location of the child’s contact with the front surface of the vehicle is illustrated in Figure 3 [47].

Figure 3

Damage to the Toyota Yaris car [47].

The brake marks of the Toyota car revealed on the roadway are indicated in Figure 4.

Figure 4

Vehicle braking traces at the scene of the accident [47].

4.3 Case study 3

The accident occurred on the roadway of the county town on a July evening, i.e., around 1.0. p.m., in a built-up area. The scene of the accident was a two-way and two-lane roadway of asphalt sidewalk with a total width of 7.5 m to which sidewalks made of paving stones with a width of 2.0 m each were adjacent on both sides. The incident involved the right front surface of a VW Bora car hitting a Moto Zeta moped turning in front of it, whose driver was a 15-year-old girl carrying her 11-year-old sister on the moped seat. As a result of the accident, the moped driver and her passenger suffered injuries to their bodies. The vehicles involved in the accident are shown in Figure 5 [47].

Figure 5

Vehicles involved in the accident [47].

In the course of reconstructing the course of the incident, the pre-collision speeds of the vehicles were determined, i.e., the speed of the VW Bora car was assumed to be about V B = 55 km/h , taking into account the following relationship V z =   5.0 m/s . – the collision speed of vehicles.

• 15.4 m/s – the speed of the VW Bora car determined on the basis of the effective braking distance of 17.0 m and taking into aount the average braking deceleration of 7.0 m/s .

The speed of the left-turning moped was assumed to be in the range of about 12.6 − 15.1 km/h ( 3.5 − 4.2 m/s ) .

The analyzed incident occurred as a result of driving errors made by the drivers of the vehicles. The driver of a Volkswagen Bora car behaved incorrectly by the fact that he overtook a single-track vehicle in a crosswalk while crossing a continuous double line located on the axis of the road, and the moped driver by the fact that, not having authorization, was driving and carrying a female passenger, and that she did not fulfill the duties incumbent on a person intending to turn left, i.e., she proceeded to turn without properly signaling her intention to change direction [47].

The relationship V B includes the component of the velocity converted into deformations of the VW Bora car, estimated at about 5 m/s , i.e., about 18 km/h , which is defined as the equivalent crash velocity (EES parameter). The second component of the VW Bora car’s speed was calculated in the equation for V hB , which takes into account the car’s deceleration during its braking on a 17-m-long road with an average deceleration of a h = 7.0 m/s 2 . Both of the aforementioned components were introduced into the equation V _B. The calculations show that the driver of the car developed a rounded speed of about 55 km/h at the scene, i.e., close to the speed limit for the scene. The summary of data is shown in Table 6.

One of the tasks of the reconstruction of the course of the analyzed incident was to identify the errors made by the participants. More precisely, the reconstruction was intended to assess the behavior of the participants in terms of compliance with traffic regulations. The errors that were pointed out above could constitute evidence material for investigative bodies or courts in the process of charging individual accident participants.

4.4 Case study 4

The accident occurred in November 2017 on a community road with total cloud cover, falling rain, and an ambient temperature of about 8°C. The road at the scene of the accident had a curve to the right and a roadway gradient of about 1.5%, looking in the direction of the moped rider. The two-way and two-lane roadway of the asphalt surface was 5.1 m wide and locally contaminated. The aforementioned roadway was driven by a 17-year-old person who was driving a ZIPP NEKEN moped. While exiting a curve, the moped rider fell on his right side and slid to the opposite lane of the roadway, where the driver of a Renault Laguna car was approaching. The moped, which was sliding on the roadway, hit the front surface of the Renault vehicle and to the moped’s impact with the front left wheel of the aforementioned passenger car. The vehicles involved in the accident are shown in Figure 6 [47].

Figure 6

Vehicles involved in the incident [47].

The speed of a moped rider moving along the curve of the roadway was determined to be about 45 km/h , taking into account the following relationship:

where 0.5 is the coefficient of friction of a lying and moving moped on wet asphalt [31], and 15.0 m is the length of the moped’s friction trace on the roadway.

The reconstruction of the course of the incident showed that the incident occurred as a result of failure to adjust the driving technique and loss of control over the single-track vehicle by the minor moped rider, who overturned on the wet surface of the curve of the roadway [47]. The summary of data is shown in Table 7.

The primary purpose of reconstructing the course of the considered traffic incident was to identify the cause of the accident that occurred and to assess the errors made by the participants of the incident as traffic participants, taking into account the conditions under which the accident occurred. In the V _t equation, the relationship under the element takes into account the length of the sliding path of the moped driver who fell on the wet roadway surface with a total length of 15 m. For the calculations, the coefficient of resistance of the overturned moped moving on the wet asphalt was assumed based on the literature (Vademecum of an expert witness, published by IES Krakow) at the level of μ =   0.5 . The calculated initial speed of the moped driver on the curve of the road and the wet surface was 12.13 s/m ( 43.67 km/h ). Taking into account the still decreasing speed of the moped when hitting the wheel rim of the car, the speed of the moped driver at the time of the fall can be assumed for further analysis at approximately 45 km/h . Taking into account the dirty surface of the wet roadway, the speed developed could have caused the moped driver to lose control of the vehicle while negotiating a curve in the road, resulting in a fall.

The above behavior of the moped driver documents his errors while driving a single-track vehicle, resulting in a fall and injury [47].