Ilya Brylev’s research while affiliated with Saint Petersburg State University of Architecture and Civil Engineering and other places

The author's team analyzed a bicycle as a two-wheeled vehicle. (TWV) The purpose of the study was to estimate the parameters affecting the reaction time of the cyclist. Depending on the type of brake system, the mass of the two-wheeled vehicle and the cyclist, the speed, and the bicycle designs graphs were built, and their analysis was carried out. Based on the test results, factors affecting the cyclist reaction time in case of danger were disclosed.

The systemic approach described in the article is designed for the development of an effective approach and purposeful measures to ensure road traffic safety. The need for a systemic approach to auditing road traffic accident black spots is justified. A conceptual model of the systemic approach to auditing road traffic accident black spots is developed. This model includes interrelations of subsystems, factors of accident-prone situations, causes of the emergence of road traffic accident black spots in the system “road user – vehicle – road – external environment”. A hierarchy of interrelations and flows in the system ensuring road traffic safety is suggested. The authors suggest considering the “Road User – Vehicle – Road – External Environment” system that includes such subsystems as the Driver (D), Pedestrian (P), Child Pedestrian (PC), Vehicle Passenger (PassV), Child Passenger (PassVC). They also suggest using the traditional term “Car subsystem” as the Vehicle (V). To account for the entire content of the “external environment” (EE) subsystem, the following structure is suggested: road infrastructure (RI) reflecting the conditions and parameters of traffic management as well as existing weather and climatic conditions. The systemic approach to auditing road traffic accident black spots reveals the potential of improving this mechanism.

Recently, in Russia, it has become relevant to conduct “audits of black spots”. It is a type of an independent audit and evaluation of the traffic safety level in the location under survey, determination of patterns in road accident causes and corresponding measures for their prevention. Traffic safety can be evaluated based on various criteria, but the reduction of the number of road accidents, especially those with injuries, has always been the most important criterion of traffic safety. In this paper, an analysis of factors that can affect elements of subsystems and the traffic safety system, in general, is conducted. Practical recommendations are provided.

The majority of countries in the world are experiencing the growing number of two-wheeled motor vehicles (motorcycles, L3 category vehicles etc.). In view of this, the number of victims and badly wounded persons is considerably increasing. Most part of road accidents is the result of certain circumstances which are forming the whole complex of causes and consequences. Determination of actual cause and contributary circumstances which occurred during the road accident is considered to be one of most important tasks regarding road traffic safety. Shortcomings commonly found in traditional methodology of calculating the motorcycle’s "while braking" speed which was developed in 1960-s and is still being used in Russian Federation lie in the fact that motorcycle speed is calculated with reference to skid marks; as a result, calculated speed often becomes "under-estimated". Experience has shown that at the moment of brakes application actual speed of motorcycles is higher than estimated because experts are using the predeterminedly under-estimated, averaged values (i) of steady state deceleration and (ii) of steady state deceleration build-up time. Contact-trace coupling of volume-penetrating nature, i.e. collision (mostly of frontal-cross nature), is causing motorcycle wheel fork deformation which results in wheel-base change. This is accompanied by kinetic energy expenditure for motorcycle deformation (including opposite vehicle deformation) which factor is commonly neglected during collision speed calculation. Most part of kinetic energy contained in the vehicle prior to collision with the barrier is transformed into plastic strain energy while the minority thereof, due to rebound strain, is again transformed into kinetic energy whose reserve is causing the vehicle to be repelled from the barrier. Authors have analyzed experiments during which motorcycles were colliding with non-deformable barriers and scrutinized the problems which were occurring while calculating the speed of two-wheeled motor vehicles during road accident.

During the last decades, designs of two-wheel motor vehicles (TWMV) have been significantly improved, which is why it is required to bring the analytical tools used to estimate their braking parameters in line with those designs. However, the current expert analysis practice applied to motor vehicle accidents (MVAs) still uses for calculations the values of deceleration time and steady state deceleration for old, domestically manufactured motorcycles which are today rarely used for travel. Both these circumstances require processing, clarification and establishing an updated basis of TWMV deceleration estimate in order to enhance credibility of such estimate used in expert examination of MVAs, i.e. to ascertain the drivers’ compliance or non-compliance with traffic regulations, to justify causes of accidents, to determine whether the driver could or could not have prevented a particular MVA.

Increase in the number of two-wheeled motor vehicles (motorcycles, vehicles of category L3) is observed in the traffic of almost all countries in the world. That is why the number of victims and people seriously injured in the road traffic accidents (RTA) has considerably increased. The majority of RTA is the result of many factors which form together sets of different causes and effects. Identification of actual reasons having led to a traffic accident, as well as their attendant circumstances, is one of the most important tasks in ensuring traffic safety. On the one hand, configurations of two-wheeled motor vehicles have been significantly improved over the last decades, so it is necessary to align the analytical apparatus of estimating parameters of the braking process with these configurations. On the other hand, the current practice of expert analysis and settlement of accidents still involves estimation of increase in braking time and steady deceleration of motorcycles manufactured domestically during the past years, which hardly participate in the modern traffic due to their age. Both of these circumstances require review and adjustment, as well as formation of an updated basis of estimate for assessment of braking processes of two-wheeled motor vehicles in order to increase the reliability of RTA examination and determine compliance or non-compliance of driver’s actions with the requirements of traffic rules, establish the causes of accidents, evaluate a technical capability of a driver of the two-wheeled motor vehicle to prevent the accident. Settlement of all these issues can be provided by effective methods of calculation (quantitative) assessment, which are not available at the present moment.