زمان عکس العمل

This study was conducted the effect of environmental factors on distracted driving. For this purpose, an applied assessment was carried out in District 5 of Tehran, and the driving performance of 37 drivers was investigated in different traffic environments (urban and rural area) and under different types of distraction sources (conversation with passenger, mobile phone).

In this study, the behavior of drivers was evaluated in an inconspicuous way using a qualitative method.

According to the findings, drivers reduce their speed when there is one of the distracting factors in urban areas, while this is not the case in rural areas. Besides, there is no difference in the lateral position with or without distraction factors in rural areas, but there are some changes in the lateral position of distracted drivers in urban areas. Conversation with passengers causes more instability of the lateral position of the vehicle and increases the driver's reaction time. Drivers keep a greater distance from the vehicle in front when conversing with passengers in rural areas compared to the absence of distracting factors. Finally, the reaction time is almost the same with or without distracting factors in rural areas.

The results show that drivers will commit fewer violations if intelligent transportation systems are used on roads. So, it is recommended that the possibility of distracting the drivers is minimized and more safety factors are provided in rural and urban roads by equipping the roads with these systems.

Increasing population growth on the one hand and the growth of transportation industry on the other have had numerous positive and negative impacts in societies. This issue has led to an increase in the volume of traffic demand in road networks and has hence increased the number of road accidents. Research shows that a large number of accidents are caused by the human factor and the vehicle factor. By using vehicle-to-vehicle communication systems and turning static conditions (off-line) into dynamic conditions (on-line), the present study attempts to turn the human factor and the vehicle factor into the intelligent human and the intelligent vehicle, respectively, and reduce their effects on the occurrence of accidents. According to Statistics, a significant percentage of freeway accidents are rear-end crashes, in which human error has the greatest effects on such collisions. Although it is obvious that the use of such communication technologies enhances the safety level of roads, the quantitative and analytical insights of the increase of safety resulting from the use of VANETs in freeways has not been investigated yet. This study offers a new method for investigating the role of vehicular ad-hoc networks (VANETs) in reducing the number of front-to-rear accidents in freeways by reducing drivers’ reaction time. In so doing, by using the micro data of the traffic flow in the I-80 freeway of the NGSIM project, drivers’ behavior in a specific time span was analyzed; and by using indices of assessment of safety of emergency breaking (UDM), the safety of drivers at each moment was investigated. The results of data analysis reveal that the use of VANET communication networks can reduce the percentage of vehicles’ exposure to danger in the chase process from 68% to 15% by reducing drivers’ reaction time.