Representativity and univocity of traffic signs and their effect on trajectory movement in a driving simulation task: Warning signs

Objective: The effect of traffic signs on the behavior of drivers is not completely understood. Knowing about how humans process the meaning of signs (not just by learning but instinctively) will improve reaction time and decision making when traveling. The economic, social, and psychological consequences of car accidents are well known.

Methods: This study sounds out which traffic signs are more ergonomic for participants, from a cognitive point of view, and determines, at the same time, their effect in participants' movement trajectories in a driving simulation task.

Results: Results point out that the signs least representative of their meaning produce a greater deviation from the center of the road than the most representative ones.

Conclusions: This study encourages both an in-depth analysis of the effect on movement of roadside signs and the study of how this effect can be modified by the context in which these signs are presented (with the aim to move the research closer to and analyze the data in real contexts). The goal is to achieve clarity of meaning and lack of counterproductive effects on the trajectory of representative signs (those that provoke fewer mistakes in the decision task).     

Assessment of patients' medical fitness to drive by primary care physicians: A cross-sectional study

Objectives: Motor vehicle collisions (MVCs) are a significant health burden in Saudi Arabia. The literature has consistently indicated that chronic medical conditions, such as diabetes, heart disease, stroke, obstructive sleep apnea, and neurodevelopmental disorders, increase the risk of MVCs. Therefore, assessment of driver fitness by primary care physicians (PCPs) remains a major health intervention that might reduce MVCs. We studied the practices of PCPs in assessing medical fitness to drive in at-risk patients.

Methods: We conducted a cross-sectional study of all 88 government-funded primary care centers in the city of Riyadh, Saudi Arabia. We administered a self-reported questionnaire to PCPs that inquired about their driving risk assessment for specific medical conditions.

Results: Among all PCPs and centers, 189 PCPs (63%) from 74 centers (84%) participated in our survey. The mean age of the PCPs was 40 ± 10 years, and 108 (57%) were men. The average clinical experience of the group was 13 ± 9 years. Fewer than half of PCPs considered diabetes mellitus (45%) and obstructive sleep apnea (46%) as potential risks for MVCs. Approximately 45% of PCPs did not notify any authority or relatives of potential driving issues that they noticed in their patients. Only 15% of the participants believed that PCPs were responsible for alerting authorities about their fitness to drive.

Conclusions: PCPs did not adequately assess their patients' driving history and eligibility. Efforts are needed to improve awareness among PCPs regarding the effects of chronic medical conditions on driving.     

Risk of serious injury of occupants involved in frontal crashes of cab-over-type trucks

Objectives: Truck vehicles (TVs) have a different structure and stiffness than non-TVs and are used commercially for transporting goods. This study aimed to analyze whether truck occupants have a greater risk of serious injury than those of other types of vehicles.

Methods: Crash data were obtained from the Korean In-Depth Data Analysis Study (KIDAS) for calendar years 2011–2016. Vehicles involved in frontal crash were included and classified into TVs and non-TVs (passenger cars and sports utility vehicles). We compared the demographic characteristics and serious injuries by body region between the 2 groups and analyzed factors that contributed to the serious injury severity from frontal crashes.

Results: The analysis was based on 884 occupants; 177 (20.0%) were in TVs and 707 (80.0%) were in non-TVs. Non-TVs had more frontal airbags deployments than TVs (50.9% vs. 3.4%, P <.01). TV occupants were 4.8 times more likely to have a serious lower extremity (LE) injury (adjusted odds ratio [AOR] = 4.820; 95% confidence interval [CI], 2.407–9.653) and 2.5 times to have a serious abdominal injury (AOR = 2.465; 95% CI, 1.108–5.487) compared to non-TV occupants.

Conclusions: Truck occupants had more serious LE and abdominal injuries than those of other types of vehicles in frontal crashes. Structural improvement and legislative efforts to develop safety systems are necessary to improve the safety of truck occupants.     

北京市道路空气中NO_x现状监测及控制对策

通过对北京城市3种典型交通道路空气中NOx的时空变化监测发现,城市道路空气NOx中NO分担率主要集中在31.6%～81.1%,明显高于非交通道路中NO的分担率(3.0%～34.0%).其原因是NO主要来源于机动车尾气的排放.利用MOBILE软件计算了各类机动车排放的ρ(NOx),并相应地确定了影响交通道路中ρ(NOx)的敏感因素.据此提出了北京市交通道路空气中NOx若干控制措施,如控制车速、车型、油料等.     

Corporate occupational exposure limits: An example of a strategy

Occupational exposure limits (OELs) developed by authorities play a key role in the implementation of programs to protect workers against hazardous chemicals. Unfortunately, many hazardous substances do not have OELs or the OEL could be outdated. To assure the health of the workers, it is therefore useful for companies to develop corporate OELs. An inhouse strategy will be presented hereafter. Expertise in toxicology, industrial hygiene, and occupational health should be available within the company and clear selection criteria for substances are needed. A corporate OEL is only developed for hazardous substances (e.g., carcinogenic or reprotoxic) with a high potential for worker exposure when an appropriate national OEL or threshold limit value is not available. The methodology to calculate corporate OELs is based on the existing methods for national or community OELs and also on the guidance from the European Union's (EU) regulation on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH). For carcinogenic substances with a nonthreshold mode of action, there is always a residual chance that a cancer develops even when the exposure of workers is low. To establish an OEL for these substances, the “German traffic light model” is recommended. It is pragmatic, defines an unacceptable, tolerable, and acceptable risk level when workers are exposed to these substances, and determines risk management for exposure reduction. Overall, the professional practice to develop OELs is a good example of corporate leadership to proactively protect the health of workers.     

Importance of awareness in improving performance of emergency medical services (EMS) systems in enhancing traffic safety: A lesson from India

Objective: India has been slow in implementing a central emergency medical services (EMS) system across the country. “108 services” is one of the most popular services that is functional under the public–private partnership model. Limited available literature shows that despite access to services, many traffic crash victims are transported using private vehicles. The objective of this study is to understand the effectiveness of 108 services from a traffic safety perspective.

Method: A questionnaire survey is conducted to understand the awareness of EMS and their function. Using traffic-related fatalities as the dependent variable, a fixed effect panel data model is developed to analyze the effectiveness of the 108 services in improving the traffic safety.

Results: The results from the survey show that, in general, people are not aware of the 108 services. A majority of the population prefers taking victims to the hospital using their personal vehicles or any other vehicles available compared to calling an ambulance. Results from panel data analysis show that despite having an efficient system, these services failed to make significant improvement in the safety of road users in the states in which their services were subscribed.

Discussion: The lack of awareness of an important safety service is alarming. This could be a major reason for lower utilization of 108 services for transporting victims of traffic crashes. This article shows the importance of having efficient awareness campaigns to improve the efficiency of any similar programs that are aimed to enhance the safety of a region.     

Development of cycling skills in 7- to 12-year-old children

Objective: Cycling is a complex skill consisting of motor skills such as pedalling, braking, and steering. Because the ability to perform cycling skills is based on the age-related development of the child, experience and age-related reference values are of interest in light of customized testing and training.

Methods: One hundred thirty-eight children from the second (7–8 years), fourth (9–10 years), and sixth (11–12 years) grades performed a practical bicycle test consisting of 13 test items with specific points of interest. Moreover, age at onset of cycling, cycling to and from school, independent mobility, and minutes cycling per week were estimated using a parental questionnaire.

Results: It is found that cycling skills are strongly related to age with 11- to 12-year-old children outperforming 7- to 8-year-old children for 11 test items and 9- to 10-year-old children for 8 test items.

Conclusions: Next to age, age at onset of cycling also contributed to cycling skills. Therefore, our results suggest that cycling skills are associated with physical and mental maturation. Subsequently, age-related reference values are provided to customize testing and training.     

Traffic accident reconstruction and an approach for prediction of fault rates using artificial neural networks: A case study in Turkey

Objective: Currently, in Turkey, fault rates in traffic accidents are determined according to the initiative of accident experts (no speed analyses of vehicles just considering accident type) and there are no specific quantitative instructions on fault rates related to procession of accidents which just represents the type of collision (side impact, head to head, rear end, etc.) in No. 2918 Turkish Highway Traffic Act (THTA 1983). The aim of this study is to introduce a scientific and systematic approach for determination of fault rates in most frequent property damage–only (PDO) traffic accidents in Turkey.

Methods: In this study, data (police reports, skid marks, deformation, crush depth, etc.) collected from the most frequent and controversial accident types (4 sample vehicle–vehicle scenarios) that consist of PDO were inserted into a reconstruction software called vCrash. Sample real-world scenarios were simulated on the software to generate different vehicle deformations that also correspond to energy-equivalent speed data just before the crash. These values were used to train a multilayer feedforward artificial neural network (MFANN), function fitting neural network (FITNET, a specialized version of MFANN), and generalized regression neural network (GRNN) models within 10-fold cross-validation to predict fault rates without using software. The performance of the artificial neural network (ANN) prediction models was evaluated using mean square error (MSE) and multiple correlation coefficient (R).

Results: It was shown that the MFANN model performed better for predicting fault rates (i.e., lower MSE and higher R) than FITNET and GRNN models for accident scenarios 1, 2, and 3, whereas FITNET performed the best for scenario 4. The FITNET model showed the second best results for prediction for the first 3 scenarios. Because there is no training phase in GRNN, the GRNN model produced results much faster than MFANN and FITNET models. However, the GRNN model had the worst prediction results. The R values for prediction of fault rates were close to 1 for all folds and scenarios.

Conclusions: This study focuses on exhibiting new aspects and scientific approaches for determining fault rates of involvement in most frequent PDO accidents occurring in Turkey by discussing some deficiencies in THTA and without regard to initiative and/or experience of experts. This study yields judicious decisions to be made especially on forensic investigations and events involving insurance companies. Referring to this approach, injury/fatal and/or pedestrian-related accidents may be analyzed as future work by developing new scientific models.     

北京大气中 NH3的分布和变化情况研究

PM2．5现在是中国大气中的主要污染物,而NH3作为前驱物,越来越受到大家的重视,在以往NH3监测中,往往采取手工采样和化学分析的方法进行监测,难以长时间不间断获得NH3的实时浓度。而选取利用Thermo公司的17i仪器则可以做到实时监测NH3的变化,继而分别对北京市区、农村和交通站周边的NH3进行了连续监测,发现市区浓度高于郊区,夏天浓度高于冬天,交通源对NH3排放有较大影响。