• Energy Research

The dynamic process of movement of vehicles in cities is associated with interaction with objects of the road environment. Road conditions, traffic and pedestrians require certain actions from the driver to ensure road safe-ty. Under such circumstances, the reliability and safety of road traffic in human-machine systems mainly depends on the functional state of the driver (provided that the technical component, the subsystem is “car”) and his ability to respond to changes in the traffic situation when obstacles arise (conflict situations). The development of states of tension and fatigue of the driver is associated with an increase in energy costs, which leads to a natural in-crease in the heart rate, respiration and other parameters indicating changes in the energy balance of the driver's body. Eye Tracking technology has been applied to detect attention. Energy costs were determined using a method that takes into account the frequency of the driver's external respiration when driving on the road and in the background. As a result, a model of change in the attention of drivers with driving experience and a model of en-ergy consumption when driving in the evening twilight at a certain level of illumination were obtained. To determine the influence of conflict situations during movement in the evening twilight on the indicator of attention and energy consumption of the driver, a study was carried out in real conditions on city streets. A group of drivers with experience of 3-5 years and 10-16 years performed arrivals in the evening twilight on passenger cars "C" class. Experimental studies of the indicator of drivers' attention and functional state in conditions of evening twilight were carried out on different categories of city streets. The study involved drivers between the ages of 20 and 40. The obtained dependences of the change in the driver's functional state on illumination showed that at low illumination levels in the evening twilight, a rapid increase in the driver's functional state shifts. Thus, the energy consumption of the driver while driving depends on the types of conflict situations and the level of illumination. It was found that for drivers with less than 5 years of driving experience, shifts in functional state were more im-portant than other drivers. Also, such drivers had lower attention indicators compared to experienced drivers with more than 10 years of driving experience. It was found that when the illumination changes at dusk, the energy consumption increases on average to 3.3 kcal / min for drivers with less than 5 years of experience, and for drivers with more than 10 years of experience, it increases by 2.4 kcal / min on average. Keywords: driver, conflict situations, attention, energy costs.

The drivers receive about 90% of the information through the vision. The road illumination is high important for vision at night. A certain level of illumination is required in order for the eyes to recognize an object. When the brightness of an object is lower than the brightness of the background, or when the brightness of an obstruction is higher than the background’s brightness, objects can be recognized by silhouette. The drivers fraught with the greatest difficulties when the road illumination changes sharply in the conditions of low light driving. Traffic accidents at night are an important issue. Although the traffic volume is low (15-20%), 41-50% of traffic accidents happen at night. For the last years more attention has been paid to transport issues that can change the cognitive and emotional state of drivers. Therefore, assessing the driver’s vision may be useful in identifying a safe or dan-gerous type of behavior on the road. Eye tracking is used to measure drivers' perception of road elements, as well as developing driving strategies and accidents preventing. During the eye fixing, the driver focuses on a specific object of road environment. The time of driver’s eye fixing may vary from 0.1 to 2.5 seconds, depending on the complexity of the road traffic and the driver's functional state. The article presents an approach to determine the driver’s attention indicators at the evening twilight on city streets. The method of recording points of regard using Pupil Labs glasses was used to attention indicators deter-mination. Experimental studies of drivers' attention indicators in the evening twilight conditions were carried out in different types of city streets. The study involved drivers aged 20 to 52 years. During the driver eye fixing, the level of illumination at the evening twilight was recorded simultaneously. When the light changes from 50 lx or less, the driver feels visual fatigue from the continuous state of road objects exploration. At the same time, the number of fixations is significantly reduced, since the driver spends more time recognizing and searching of traffic elements, pedestrians, etc. Keywords: driver, twilight conditions, road traffic, attention.