Research into the Safe Distance for Opening a Car Door in Order to Avoid Approaching Motorcycles from the Rear

Car drivers may misjudge the speed and distance of oncoming vehicles when getting out of their vehicles, leading to door crash accidents. The author invented a patented side-view mirror with distance markers to prevent such door crash accidents. Through the means of behavioural observation experiments, the main objective of this research was to observe the minimum safe distance from the rear of an approaching vehicle when opening the door of the car. The experimental results determined that the use of the Dutch Reach method yielded the shortest safe distance. Compared to the other three judgment solutions, the use of the patented side-view mirror with a distance marker to judge the minimum average safety distance had the longest distance and was the safest, meaning that it is able to help female drivers to judge the distance of approaching motorcycles from the rear and to maintain a sufficient safe distance when opening the door.

On the issue of assessing the errors in the operation of an interactive system for improving road safety outside settlements

The article presents the result of the analysis of statistical data of accidents in the Krasnoyarsk Territory on sections of roads outside settlements with their greatest concentration. The main types of vehicle collisions and their accompanying conditions were identified. A mathematical apparatus for determining the minimum safe distance between vehicles located closely in an emergency zone on a section of a road outside settlements is proposed, in which it is necessary to notify the drivers of these vehicles about the danger in conditions of insufficient and/or limited visibility in various road situations, taking into account errors in positioning and determining the speed of the vehicle, the response time of the system, the effective coefficient of adhesion of the tires to the road surface. The results of experimental studies of vehicle positioning and speed errors determined by the driver’s early warning system about hazards on the road and their impact on the operability of the designed system are presented. Keywords: road safety, interactive driver warning system, positioning error, safe distance, rest of track, braking distance

State movement for controlling trains operating under the virtual coupling system

Train Virtual Coupling System (VCS) has been proposed as a new signalling system for controlling trains by building a group of trains as convoys in order to increase line’s capacity. This is achieved because the consecutive trains under the VCS is separated only by a relative braking distance; this is much shorter than the separation distance required in the Fixed Block Signaling (FBS) and Moving Block Signaling systems (MBS). In order to achieve the high capacity obtained from the VCS, the trains in a virtually coupled convoy should keep at a distance as close to the relative braking distance as possible and run at the same speed for maintaining the safe distance between them. In this paper, we propose a distance and velocity difference approach and introduce the multiple state movements for stimulating train’s movement under the VCS. The simulated results show that the capacity can be significantly increased and maximized in which the actual separation distance between trains when they are in convoy state is slightly longer than the minimum safe distance. It could be ensured that the train has proceeded safely in that the actual separation distance is surely longer than the minimum safe distance throughout the operation time period. In addition, we show that the trains can also proceed smoothly, in that a following train catches up with its leading train and joined in the convoy with a stable movement.

Modeling and Analysis on Minimum Safe Distance for Platooning Vehicles Based on Field Test of Communication Delay

Vehicle platooning is a perspective technique for intelligent transportation systems (ITS). Connected and automated vehicles (CAVs) use dedicated short-range communication (DSRC) to form a convoy, in which the following vehicles can receive the information from their preceding vehicles to achieve safe automated driving and maintain a short headway. Consequently, a vehicle platoon can improve traffic safety and efficiency, further reducing fuel consumption. However, emergency braking inevitably occurs when the platoon meets an accident or a sudden mechanical failure. It is more critical when the wireless communication got delays. Therefore, “how to predefine a minimum safe distance (MSD) considering communication delay” is a challenging issue. To this end, a series of field tests were carried out to measure the communication delay of IEEE 802.11p that is the underlying protocol of DSRC. Subsequently, MSD is modeled and analyzed when the platoon travels at accelerating, cruising, and decelerating states. More importantly, the results of field tests are applied in the models to investigate the impact of communication delay on MSD in practice. The simulation results verify that the proposed model can effectively maintain the platooning vehicles’ safety even if emergency braking happens with certain communication delays.

PREREQUISITE FOR ACCIDENT-FREE TRAFFIC AT SIGNAL-CONTROLLED INTERSECTIONS

Introduction: Improving intersection capacity will not be possible without accounting for traffic safety. Purpose of the study: We aim to determine the prerequisite for accident-free traffic at signal-controlled intersections with turning traffic flows. Methods: In our study, we used the methods of observation, comparison, and mathematical analysis. Results: We have carried out a field observation of traffic intensity at signal-controlled intersections in the city of Yekaterinburg, focusing on vehicles that moved when the green light was on. We have also analyzed traffic flow moving in three directions in the same lanes. We have discovered that traffic accident likelihood is the highest (54%) at four-way intersections. Three-way intersections account for 44% of traffic accidents, while the remaining 2% of accidents occur at multi-way intersections. Furthermore, we have determined the additional factors that impact safety in turning traffic flows at intersections. Our study demonstrates that in order to ensure maximum intersection capacity, the duration of the traffic signal cycle must be adjusted with the minimum safe distance between vehicles in mind.

Prediction of the Collapse Region Induced by a Concealed Karst Cave above a Deep Highway Tunnel

The presence of a concealed karst cave above a deep highway tunnel may cause the collapse of the rock mass between the karst cave and tunnel during excavation. Rock mass collapse threatens the safety of tunnel construction personnel. A prediction method of the collapse region induced by a concealed karst cave above a deep highway tunnel is proposed on the basis of the upper bound theorem of limit analysis. An analytical expression of the collapse surface is derived from the variational principle. Using the analytical expression of the collapse surface, the shapes of the collapse surfaces are plotted for different rock mass parameters. Moreover, the minimum safe distance between the karst cave and tunnel is defined, and the computational equation of the minimum safe distance is derived. The proposed method is applied in a highway tunnel excavated in a karst terrain as a case study. Based on geological survey report parameters, the shape of the collapse surface and the minimum safe distance between the karst cave and tunnel are obtained. Finally, the collapse surface of the rock mass provided by the proposed approach is compared with that provided by numerical simulation, and the favorable result comparison shows that the proposed method is valid.

Lack of sufficient public space can limit the effectiveness of COVID-19’s social distancing measures

One of the primary strategies of slowing down the COVID-19 pandemic has been the establishment of social distancing rules that recommend keeping a buffer distance between individuals, and this has proven effective in helping in reducing the basic reproduction number [R 0]1. However, social distancing rules have put the use of public spaces in densely populated places under strain, and this is especially important as some of the most virulent outbreaks of the COVID-19 pandemic have been in compact cities. It is therefore fundamental to take into account each neighbourhood’s morphological characteristics and the potential population densities each street, square or park can accommodate under such new regulations in order to effectively enforce social distancing rules. Otherwise, certain areas may be rapidly overwhelmed by crowds with citizens unable to maintain the minimum safe distance between individuals. In this paper, we develop a method to identify the potential public space accessibility if social distancing rules are followed and we apply it to three global and highly affected by COVID-19 cities. Our research finds that, at micro level there are important inequalities between neighbourhoods, so people will struggle to comply with social distancing rules and consequently it will make controlling infection rates more difficult.

Coping with Coronavirus: A Personal Experience and The Response of an English Village.

Every country had been unprepared for the onslaught of coronavirus (Covid- 19), and there have been all sorts of problems. In England the essential services have continued to function, but with considerable difficulty[1]. Hospitals have had to cancel almost all appointments, but struggle on with the absolutely necessary cases. Letters and milk are still delivered though not necessarily on every day. Rubbish collection continues but teams are reduced from three to two men, in order to maintain safe distances between the workers. Many shops stay open but with restrictions. The supermarkets have special layouts and limits on the number allowed in at any one time – when one person leaves another is allowed in. In all situations, the minimum safe distance allowed between individuals, other than family members living together, is ten feet.

Determination of Minimum Distance to Obstacle Avoidance in the Singapore Strait

In the maritime simulation models of obstacle avoidance, the parameter of critical contact closest point of approach (CCPA) is defined as the minimum safe distance to avoid an obstacle contact. Although the parameter of CCPA plays a decisive role on the maneuvering of the ship for obstacle avoidance, it is generally set with an uncalibrated input value in many obstacle avoidance simulation models. This study focuses on the parameter calibration of the critical CCPA by utilizing the automatic identification system (AIS) data in the Singapore Strait and maneuver simulation experiments. First, an effective mathematical method is proposed to identify ship obstacle avoidance from the big AIS data. Together with several obstacles and the AIS data in the Singapore Strait, the average critical CCPA values are identified for different ship classes. Second, a series of maneuver simulation experiments on Dalian Maritime University navigational simulators are conducted by professional captains. Based on the experimental data, the simulation-based critical CCPA values are derived. Finally, these calibrated CCPA values from the above two methods are compared and analysed. The comparison result implies that these critical CCPA values, derived from AIS data and maneuver simulators, are matched and confirm the rationality of one another. It also reveals that the average critical CCPA value for each ship class has an increasing trend with the increased ship length.