Empirical evaluation of drivers’ start-up behavior at signalized intersection using driving simulator

Start-up behavior at signalized intersection mainly depends on perception reaction time of drivers to the green phase. This study investigated the start-up behavior at signalized intersections by considering reaction time, acceleration and jerk (the rate of change of acceleration) of drivers in the state of Qatar. Distributions for reaction time, acceleration and jerk were plotted and the mean and 50th percentile values were presented. Three demographic factors (i.e., gender, ethnicity and age) were analyzed using two-tailed/unpaired t-tests. The relationships between acceleration and reaction time, and jerk and reaction time were investigated by linear regression analyses. Descriptive analysis showed that drivers had a mean reaction time of 2.91 s. Furthermore, Arab drivers had significantly lower reaction time than non-Arab drivers. Regarding the jerk maneuvers, young drivers (below 30 years) displayed significantly higher jerk than drivers of 30 years or above. Results from linear regressions showed significant negative correlations in both models (i.e., reaction time on acceleration, reaction time on jerk). As this study targeted multi-cultural drivers’ population, the results of reaction time and jerk distributions could be used as inputs in simulation models which are developed for evaluating driver behavior and safety at signalized intersections in regions with multi-cultural driving population

THE MEDIATING ROLE OF PERSONALITY IN THE RELATIONSHIP BETWEEN REACTION TIME AND TRAFFIC PERCEPTION IN YOUNG ADULTS

The objective of this research was to examine how personality acts as a mediator in the relationship between reaction time and traffic perception in young adults. Given the increase in the number of road accidents among this age group in the European Union, it is essential to understand the psychological determinants of risky driving behavior. A sample of 60 participants from Poland, Slovakia, and Lithuania was assessed using the Vienna Test System to measure personality, reaction time, time-movement anticipation, and traffic perceptions. The results indicate gender differences in self-control personality factor and motor reaction time, as well as a positive correlation between the sense of responsibility and time-movement anticipation. The proposed model was confirmed, demonstrating that mental stability mediates the relationship between reaction time and traffic perceptions. A driver with high mental stability can react faster to stimuli while accurately perceiving objects in road traffic. This study has implications for road safety policies and practices. Incorporating personality assessments into driver training programs can help develop interventions that target specific personality traits. Furthermore, interventions aimed at enhancing mental stability may help reduce the likelihood of accidents among young drivers. However, this study’s limitations, such as the small sample size and narrow age range, should be considered in future research with other age groups and additional variables that directly impact traffic safety

Promoting cycling activities in the State of Qatar: Challenges and potential treatments

In the last few decades, cycling has received an increased attention due to its health, social, and economical benefits. Many countries are adopting different policies to encourage cycling as a daily mode of transport. In this paper, the main barriers and motivators to cycling and their relation to demographic factors were investigated. In addition, main trip purposes of cycling and the effect of seasonal variation on trips duration were studied in the State of Qatar. Data was obtained through questionnaire by interviewing 272 respondents. Descriptive statistics and correlations were conducted to investigate the causal relationships. Most of the respondents reported that they cycle for exercise/leisure purpose. Due to weather conditions, cyclists are willing to cycle more in the winter season compared to summer for all trip purposes. Results also revealed a significant relation between different barriers/motivators and demographic factors such as gender, age and ethnicity. The results of this study could be beneficial to policymakers in identifying the main barriers and motivators for the public in order to promote cycling.Qatar University Student Grant [QUST-1-CENG-2022-384

Analysis of gap parameters for the estimation of single lane roundabouts' capacity in the State of Qatar

Entry capacity is an important parameter for evaluating the roundabout performance. In general, entry capacity is influenced by three gap parameters: critical gap, follow-up time and minimum headway of circulating vehicles. These gap parameters certainly are correlated with the driving behavior as well as the roundabout characteristics. In this paper, video records of two single roundabouts in the state of Qatar were used to estimate the gap parameters. In addition, the entry capacity of both roundabouts was estimated and compared through different methodologies. Results showed that the entry capacity is directly related with the inscribed circle diameter (ICD) until 400 vph of circulating flow. However, it is inversely related with ICD if the circulating flow exceeds 400 vph. Moreover, we found that the entry capacity has a negative relation with the gap parameters. Estimated entry capacities with the calibrated Highway Capacity Manual 6th Edition model (HCM, 2016) were significantly higher than estimated ones through the proposed approach by Qatar Highway Design Manual (QHDM, 2015). Interestingly, the entry capacity was underestimated in both approaches if default gap parameter values are used compared to the calibrated models using the observed gap parameters (36.7% less for HCM, and 19.4% less for QHDM). Thus, the utilization of realistic gap parameter values representing local traffic condition is essential for traffic planners to accurately estimate the entry capacity and accordingly ensure feasible design of different types of roundabouts

Do detection-based warning strategies improve vehicle yielding behavior at uncontrolled midblock crosswalks?

Pedestrians being the most vulnerable road users account for a large proportion of injuries and fatalities from road traffic crashes. Pedestrians are involved in around one-third of the whole fatalities coming from the road traffic crashes in the state of Qatar. In areas with uncontrolled midblock crosswalks, it is very crucial to improve drivers’ alertness and yielding behavior. The objective of this driving simulator study is to investigate the impact of pedestrian detection strategies and pavement markings on driving behavior at high-speed uncontrolled crosswalks. To this end, an untreated condition (i.e. Control) was compared with three treatment conditions. The three treated conditions included two detection strategies, i.e., advance variable message sign (VMS) and LED lights, and road markings with pedestrian encircled. Each condition was tested with a yield/stop controlled marked crosswalk for two situations, i.e. with vs. without a pedestrian present. The experiment was conducted using the driving simulator at Qatar University. In total, 67 volunteers possessing a valid Qatari driving license participated in the study. Different analyses were conducted on vehicle-pedestrian interactions, driving speed, variations in acceleration/deceleration and lateral position. The results showed that both the LED and VMS conditions were helpful in increasing yielding rates up to 98.4 % and reducing the vehicle-pedestrian conflicts significantly. Furthermore, both treatments were effective in motivating drivers to reduce vehicle speed in advance. Considering the findings of this study, we recommend LED and VMS conditions as potentially effective solutions to improve safety at yield/stop controlled crosswalks.The NPRP award [NPRP 9-360-2-150] from the Qatar National Research Fund (a member of Qatar Foundation). Open Access funding provided by the Qatar National Library

Road safety status during COVID-19 pandemic: exploring public and road safety expert’s opinions

The main objective of this study is to investigate the status of traffic safety and the public perception of traffic safety during the during COVID-19 pandemic. Three different data sets are used in this study: road crash and traffic violation data from Qatar, and two separate questionnaire surveys (from general public and road safety experts). Results showed that during COVID-19 period, the total number of crashes in Qatar significantly reduced during the pandemic compared with the previous 5 years. However, the rates of serious and fatal injuries significantly increased. Regarding the general public perceptions, more than 80% reported that roads became safer while driving behaviours improved during the pandemic. On the other hand, more than 50% of the experts disagreed that roads became safer, 55% disagreed that driving behaviours improved and 70% agreed that less attention from governments was directed toward road safety during the pandemic. The findings from this study could help policy makers to understand the road safety status during the pandemic to make appropriate adjustments in the traffic laws and regulations on a temporary basis. This could help in reducing crash-related injuries and as a result reduce pressure on health and other emergency services.Open Access funding provided by the Qatar National Library. This publication was made possible by the Collaborative Grant [QUCG-CENG-21/22-2] from the Qatar University