Driver’s Shy Away Effect in Urban Extra-Long Underwater Tunnel

For urban extra-long underwater tunnels, the obstacle space formed by the tunnel walls on both sides has an impact on the driver\u27s driving. The aim of this study is to investigate the shy away characteristics of drivers in urban extra-long underwater tunnels. Using trajectory offset and speed data obtained from real vehicle tests, the driving behaviour at different lanes of an urban extra-long underwater tunnel was investigated, and a theory of shy away effects and indicators of sidewall shy away deviation for quantitative analysis were proposed. The results show that the left-hand lane has the largest offset and driving speed from the sidewall compared to the other two lanes. In the centre lane there is a large fluctuation in the amount of deflection per 50 seconds of driving, increasing the risk of two-lane collisions. When the lateral clearances are increased from 0.5 m to 2.19 m on the left and 1.29 m on the right, the safety needs of drivers can be better met. The results of this study have implications for improving traffic safety in urban extra-long underwater tunnels and for the improvement of tunnel traffic safety facilities

A Study On the Effectiveness of Rolling Barrier System at Straight Road and Curved Road: A Review

The rolling barrier system is part of the road safety infrastructure that is used to improve and maintain road safety. It is also possible to overcome and reduce the number of crashes. A rolling barrier is a type of safety device that not only absorbs but also converts shock energy into rotational energy, thereby preventing fatal accidents for drivers and passengers. A rolling barrier should be installed in areas where vehicles are frequently collided. By absorbing shock energy, a rolling barrier will safely guide a vehicle back to the road or stopped the vehicle. This study was built on the findings of a previous study to determine the effectiveness of a rolling barrier system for use on both straight and curved roads. This research focuses on a new invention, the rolling barrier system, as opposed to the traditional barrier, in order to learn more about its mechanism and function. The study's scope was limited to focusing on the implementation of the rolling barrier system on straight and curved roads. According to the previous study, straight and curved roads have the highest incident rates compared to other types of roads. The Rolling Barrier System was strategically installed in three high-risk areas with a high incidence of fatal traffic incidents. The three high-risk road locations that require additional safety are straight roads, curving roads, and hilly roads, which are the most important locations to place Rolling Barrier Systems in order to decrease high-risk accidents and fatalities while also improving road safety. There are four types of roads that are appropriate for implementing a Rolling Barrier System. The Rolling Barrier types are straight roadside Rolling Barriers, curved roadside Rolling Barriers, steep roadside Rolling Barriers, and median Rolling Barriers

A Study On the Effectiveness of Rolling Barrier System at Straight Road and Curved Road: A Review

The rolling barrier system is part of the road safety infrastructure that is used to improve and maintain road safety. It is also possible to overcome and reduce the number of crashes. A rolling barrier is a type of safety device that not only absorbs but also converts shock energy into rotational energy, thereby preventing fatal accidents for drivers and passengers. A rolling barrier should be installed in areas where vehicles are frequently collided. By absorbing shock energy, a rolling barrier will safely guide a vehicle back to the road or stopped the vehicle. This study was built on the findings of a previous study to determine the effectiveness of a rolling barrier system for use on both straight and curved roads. This research focuses on a new invention, the rolling barrier system, as opposed to the traditional barrier, in order to learn more about its mechanism and function. The study's scope was limited to focusing on the implementation of the rolling barrier system on straight and curved roads. According to the previous study, straight and curved roads have the highest incident rates compared to other types of roads. The Rolling Barrier System was strategically installed in three high-risk areas with a high incidence of fatal traffic incidents. The three high-risk road locations that require additional safety are straight roads, curving roads, and hilly roads, which are the most important locations to place Rolling Barrier Systems in order to decrease high-risk accidents and fatalities while also improving road safety. There are four types of roads that are appropriate for implementing a Rolling Barrier System. The Rolling Barrier types are straight roadside Rolling Barriers, curved roadside Rolling Barriers, steep roadside Rolling Barriers, and median Rolling Barriers

Autonomous Control and Automotive Simulator Based Driver Training Methodologies for Vehicle Run-Off-Road and Recovery Events

Traffic fatalities and injuries continue to demand the attention of researchers and governments across the world as they remain significant factors in public health and safety. Enhanced legislature along with vehicle and roadway technology has helped to reduce the impact of traffic crashes in many scenarios. However, one specifically troublesome area of traffic safety, which persists, is run-off-road (ROR) where a vehicle\u27s wheels leave the paved portion of the roadway and begin traveling on the shoulder or side of the road. Large percentages of fatal and injury traffic crashes are attributable to ROR. One of the most critical reasons why ROR scenarios quickly evolve into serious crashes is poor driver performance. Drivers are unprepared to safely handle the situation and often execute dangerous maneuvers, such as overcorrection or sudden braking, which can lead to devastating results. Currently implemented ROR countermeasures such as roadway infrastructure modifications and vehicle safety systems have helped to mitigate some ROR events but remain limited in their approach. A complete solution must directly address the primary factor contributing to ROR crashes which is driver performance errors. Four vehicle safety control systems, based on sliding control, linear quadratic, state flow, and classical theories, were developed to autonomously recover a vehicle from ROR without driver intervention. The vehicle response was simulated for each controller under a variety of common road departure and return scenarios. The results showed that the linear quadratic and sliding control methodologies outperformed the other controllers in terms of overall stability. However, the linear quadratic controller was the only design to safely recover the vehicle in all of the simulation conditions examined. On average, it performed the recovery almost 50 percent faster and with 40 percent less lateral error than the sliding controller at the expense of higher yaw rates. The performance of the linear quadratic and sliding algorithms was investigated further to include more complex vehicle modeling, state estimation techniques, and sensor measurement noise. The two controllers were simulated amongst a variety of ROR conditions where typical driver performance was inadequate to safely operate the vehicle. The sliding controller recovered the fastest within the nominal conditions but exhibited large variability in performance amongst the more extreme ROR scenarios. Despite some small sacrifice in lateral error and yaw rate, the linear quadratic controller demonstrated a higher level of consistency and stability amongst the various conditions examined. Overall, the linear quadratic controller recovered the vehicle 25 percent faster than the sliding controller while using 70 percent less steering, which combined with its robust performance, indicates its high potential as an autonomous ROR countermeasure. The present status of autonomous vehicle control research for ROR remains premature for commercial implementation; in the meantime, another countermeasure which directly addresses driver performance is driver education and training. An automotive simulator based ROR training program was developed to instruct drivers on how to perform a safe and effective recovery from ROR. A pilot study, involving seventeen human subject participants, was conducted to evaluate the effectiveness of the training program and whether the participants\u27 ROR recovery skills increased following the training. Based on specific evaluation criteria and a developed scoring system, it was shown that drivers did learn from the training program and were able to better utilize proper recovery methods. The pilot study also revealed that drivers improved their recovery scores by an average of 78 percent. Building on the success observed in the pilot study, a second human subject study was used to validate the simulator as an effective tool for replicating the ROR experience with the additional benefit of receiving insight into driver reactions to ROR. Analysis of variance results of subjective questionnaire data and objective performance evaluation parameters showed strong correlations to ROR crash data and previous ROR study conclusions. In particular, higher vehicle velocities, curved roads, and higher friction coefficient differences between the road and shoulder all negatively impacted drivers\u27 recoveries from ROR. The only non-significant impact found was that of the roadway edge, indicating a possible limitation of the simulator system with respect to that particular environment variable. The validation study provides a foundation for further evaluation and development of a simulator based ROR recovery training program to help equip drivers with the skills to safely recognize and recover from this dangerous and often deadly scenario. Finally, building on the findings of the pilot study and validation study, a total of 75 individuals participated in a pre-post experiment to examine the effect of a training video on improving driver performance during a set of simulated ROR scenarios (e.g., on a high speed highway, a horizontal curve, and a residential rural road). In each scenario, the vehicle was unexpectedly forced into an ROR scenario for which the drivers were instructed to recover as safely as possible. The treatment group then watched a custom ROR training video while the control group viewed a placebo video. The participants then drove the same simulated ROR scenarios. The results suggest that the training video had a significant positive effect on drivers\u27 steering response on all three roadway conditions as well as improvements in vehicle stability, subjectively rated demand on the driver, and self-evaluated performance in the highway scenario. Under the highway conditions, 84 percent of the treatment group and 52 percent of the control group recovered from the ROR events. In total, the treatment group recovered from the ROR events 58 percent of the time while the control group recovered 45 percent of the time. The results of this study suggest that even a short video about recovering from ROR events can significantly influence a driver\u27s ability to recover. It is possible that additional training may have further benefits in recovering from ROR events

Integrating spatial and temporal approaches for explaining bicycle crashes in high-risk areas in Antwerp (Belgium)

The majority of bicycle crash studies aim at determining risk factors and estimating crash risks by employing statistics. Accordingly, the goal of this paper is to evaluate bicycle-motor vehicle crashes by using spatial and temporal approaches to statistical data. The spatial approach (a weighted kernel density estimation approach) preliminarily estimates crash risks at the macro level, thereby avoiding the expensive work of collecting traffic counts; meanwhile, the temporal approach (negative binomial regression approach) focuses on crash data that occurred on urban arterials and includes traffic exposure at the micro level. The crash risk and risk factors of arterial roads associated with bicycle facilities and road environments were assessed using a database built from field surveys and five government agencies. This study analysed 4120 geocoded bicycle crashes in the city of Antwerp (CA, Belgium). The data sets covered five years (2014 to 2018), including all bicycle-motorized vehicle (BMV) crashes from police reports. Urban arterials were highlighted as high-risk areas through the spatial approach. This was as expected given that, due to heavy traffic and limited road space, bicycle facilities on arterial roads face many design problems. Through spatial and temporal approaches, the environmental characteristics of bicycle crashes on arterial roads were analysed at the micro level. Finally, this paper provides an insight that can be used by both the geography and transport fields to improve cycling safety on urban arterial roads

Determination of curve speed zones for mountainous freeways

Different vehicular speed limits may have an impact on the balance between safety and efficiency of travel on mountainous road corners associated with complex road conditions. Placing suitable speed limit warning signs does not merely effectively improve traffic safety but can also improve traffic efficiency. In this study, a global positioning system (GPS) terminal and Metrocount were used to collect vehicle speed data from more than 40 provincial-level curves in 8 provinces over the course of 1 year. Each road data collection time-period lasted approximately 8 hours. A descriptive statistics method was adopted by means of data screening and pretreatment. Additionally, both a velocity difference estimation model was established and a linear model of velocity differential estimation was constructed. Quantitative analysis was carried out on the safe speed, the driver’s expected speed, and the location of the speed limit warning signs. This demonstrated a positive correlation with the initial speed. When the difference in speed was greater than 15 km/h, a safety warning sign was required to limit the design speed to 80 km/h. A safety warning sign was also required when the corner radius was less than 300 m. The location of safety warning signs could be calculated based on the operating speed and taking driving safety and the visual range of drivers into consideration. The results can provide a theoretical reference for setting up appropriate safe speed limiting signs on road corners in mountainous areas

Intelligent Driving Assistant based on Road Accident Risk Map Analysis and Vehicle Telemetr

El estudio espuesto a continuación presenta el desarrollo de un asistente inteligente de conducción basado en telemetría vehicular y análisis de mapas de riesgo de accidentalidad vial, cuya responsabilidad es alertar al conductor conforme se lleva a cabo el proceso de conducción para evitar de esta forma situaciones riesgosas que puedan ocasionar accidentes de tránsito. El asistente inteligente a bordo del vehículo reproduce alertas visuales-auditivas en tiempo real de acuerdo a la información obtenida de ambas fuentes, y las conducciones realizadas para su desarrollo y evaluación son obtenidas por un automóvil real en un entorno real. Como resultado, se obtuvo un agente de asistencia inteligente basado en el razonamiento difuso, que apoya correctamente al conductor en tiempo real de acuerdo a los datos de telemetría, al entorno vehicular y a los principios de prácticas seguras de conducción y regulación de transporte.

Road safety investigation of the interaction between driver and cyclist

With growing global concern to reduce CO2 emissions, the transportation modal shift from car to bicycle is an encouraging alternative, which is getting more popular in Europe and North America, thanks to very low impact on the environment. On the other hand, the infrastructure for cyclist should be improved, since cyclists are vulnerable road users and with an increase in the number of cyclists the concern for their safety also gets increased. In this thesis, the analysis of accidents in which cyclists have been involved and understanding the reason for these accidents have been discussed, then the necessary requirements to design and implement a safe bicycle network is introduced. The study focuses on the drivers’ behavior in terms of interaction with cyclists when there is a presence of a cyclist crossing. Therefore the road safety investigation on cyclist infrastructure was made with observing drivers’interaction with cyclists. Then the time-based surrogacy measures used to investigate the safety level of the cylist, in particular PET (Post Encroachment Time) and TTC (Time to Collision) between driver and bicyclist were determing keeping in mind the right-angle collision. Furthermore we tried to find the reaction time of the drivers especially on signals and also with the presence of cyclist on the crossing to understand the time which is needed for the driver to stop the car. All of this data could be later useful for the reconstruction of the accidents. Understanding the instants at which driver applies the brakes was made possible by installing a V-Box device inside our test vehicle which also used to determine measures such as speed, distance and other important. Finally using mobile eye tracker the driver visual behavior when arriving the crossing point where observed and results showed that at number of situations driver’s gaze was distracted and only cyclist became an important focus only when he was at a considerable length from the crossing

Safety Issues Of Red-light Running And Unprotected Left-turn At Signalized Intersections

Crashes categorized as running red light or left turning are most likely to occur at signalized intersections and resulted in substantial severe injuries and property damages. This dissertation mainly focused on these two types of vehicle crashes and the research methodology involved several perspectives. To examine the overall characteristics of red-light running and left-turning crashes, firstly, this study applied 1999-2001 Florida traffic crash data to investigate the accident propensity of three aspects of risk factors related to traffic environments, driver characteristics, and vehicle types. A quasi-induced exposure concept and statistical techniques including classification tree model and multiple logistic regression were used to perform this analysis. Secondly, the UCF driving simulator was applied to test the effect of a proposed new pavement marking countermeasure which purpose is to reduce the red-light running rate at signalized intersections. The simulation experiment results showed that the total red-light running rate with marking is significantly lower than that without marking. Moreover, deceleration rate of stopping drivers with marking for the higher speed limit are significantly less than those without marking. These findings are encouraging and suggesting that the pavement marking may result in safety enhancement as far as right-angle and rear-end traffic crashes at signalized intersections. Thirdly, geometric models to compute sight distances of unprotected left-turns were developed for different signalized intersection configurations including a straight approach leading to a straight one, a straight approach leading to a curved one, and a curved approach leading to a curved one. The models and related analyses can be used to layout intersection design or evaluate the sight distance problem of an existing intersection configuration to ensure safe left-turn maneuvers by drivers