scholarly journals Urban Road Crashes and Weather Conditions: Untangling the Effects

2019 ◽  
Vol 11 (11) ◽  
pp. 3176 ◽  
Author(s):  
António Lobo ◽  
Sara Ferreira ◽  
Isabel Iglesias ◽  
António Couto
Keyword(s):  
Negative Binomial ◽  
Weather Conditions ◽  
Crash Risk ◽  
Traffic Crash ◽  
Road Crashes ◽  
Road Users ◽  
Poisson Models ◽  
Adverse Weather ◽  
Single Vehicle ◽  
The Impact

Most previous studies show that inclement weather increases the risk of road users being involved in a traffic crash. However, some authors have demonstrated a little or even an opposite effect, observed both on crash frequency and severity. In urban roads, where a greater number of conflict points and heavier traffic represent a higher exposure to risk, the potential increase of crash risk caused by adverse weather deserves a special attention. This study investigates the impact of meteorological conditions on the frequency of road crashes in urban environment, using the city of Porto, Portugal as a case study. The weather effects were analyzed for different types of crashes: single-vehicle, multi-vehicle, property-damage-only, and injury crashes. The methodology is based on negative binomial and Poisson models with random parameters, considering the influence of daily precipitation and mean temperature, as well as the lagged effects of the precipitation accumulated during the previous month. The results show that rainy days are more prone to the occurrence of road crashes, although the past precipitation may attenuate such effect. Temperatures below 10 °C are associated with higher crash frequencies, complying with the impacts of precipitation in the context of the Portuguese climate characteristics.

scholarly journals The Effect of Ethyl Alcohol upon Pedestrian Trauma Sustained in Traffic Crashes

2019 ◽  
Vol 16 (8) ◽  
pp. 1471 ◽  
Author(s):  
Witold Pawłowski ◽  
Dorota Lasota ◽  
Mariusz Goniewicz ◽  
Patryk Rzońca ◽  
Krzysztof Goniewicz ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Road Traffic ◽  
Motor Vehicles ◽  
Medical Documentation ◽  
Traffic Crash ◽  
Young Males ◽  
Road Crashes ◽  
Road Users ◽  
Medical University ◽  
The Impact

Introduction: Every year more than 1.2 million people worldwide die due to trauma sustained in road crashes, with an additional number of people injured exceeding 50 million. To a large extent, this applies to so called “unprotected road users”, including pedestrians. The risk involved in a traffic crash for pedestrians can result from many factors, one of which is participation in road traffic when under the influence of alcohol. The aim of this study was to analyze the impact of alcohol use among pedestrians as unprotected road traffic participants, and the consequences of them being struck by motor vehicles. Material and methods: The source of data was the medical documentation of the Department of Forensic Medicine at the Medical University of Warsaw. The sample for this research consisted of 313 pedestrians who were victims of fatal road crashes resulting from a collision with a mechanical vehicle. The obtained results were subjected to statistical analysis using the STATISTICA version 12.5 program (StatSoft Polska, Cracow, Poland). Results: Male fatalities constituted the majority of the study sample. Nearly half of the fatal pedestrian victims were found to be under the influence of alcohol. The statistical analysis demonstrated a significant relationship between the gender and age of the victims, as well as between the place of the event, the place of death, the mechanism of the event, and the presence of alcohol in pedestrians. Conclusions: Among pedestrians, victims of road crashes who were under the influence of alcohol were predominantly drunk young males. Victims under the influence of alcohol were more likely to become fatalities in crashes where the mechanism of the incident was being struck by a passenger car, and when the place of the incident was a rural area, in these cases the rates of death directly at the scene were much more frequent. The eradication of alcohol consumption by all road users should be the overriding objective of all measures aimed at reducing the number of road crashes.

scholarly journals Predicting Wet-Road Crashes Using the Finite-Mixture Zero-Truncated Negative Binomial Model

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Ying Chen ◽  
Zhongxiang Huang
Keyword(s):  
Traffic Safety ◽  
Negative Binomial ◽  
Safety Data ◽  
Method Comparison ◽  
Weather Conditions ◽  
Finite Mixture ◽  
Crash Risk ◽  
Crash Data ◽  
Road Crashes ◽  
Inclement Weather

Inclement weather affects traffic safety in various ways. Crashes on rainy days not only cause fatalities and injuries but also significantly increase travel time. Accurately predicting crash risk under inclement weather conditions is helpful and informative to both roadway agencies and roadway users. Safety researchers have proposed various analytic methods to predict crashes. However, most of them require complete roadway inventory, traffic, and crash data. Data incompleteness is a challenge in many developing countries. It is common that safety researchers only have access to data on sites where a crash has occurred (i.e., zero-truncated data). The conventional crash models are not applicable to zero-truncated safety data. This paper proposes a finite-mixture zero-truncated negative binomial (FMZTNB) model structure. The model is applied to three-year wet-road crash data on 395 divided roadway segments (total 586 km), and the parameters are estimated using the Markov chain Monte Carlo (MCMC) method. Comparison indicates that the proposed FMZTNB model has better fitting performance and is more accurate in predicting the number of wet-road crashes. The model is capable of capturing the heterogeneity within the sample crash data. In addition, lane width showed mixed effects in different components on wet-road crashes, which are not observed in conventional modeling approaches. Practitioners are encouraged to consider the finite-mixture zero-truncated modeling approach when complete safety dataset is not available.

scholarly journals Wpływ warunków meteorologicznych na zachorowalność na grypę w wybranych polskich miastach = Impact of meteorological conditions on influenza morbidity in the selected Polish cities

2021 ◽  
Vol 93 (1) ◽  
pp. 103-122
Author(s):  
Katarzyna Lindner-Cendrowska
Keyword(s):  
Wind Speed ◽  
Negative Binomial ◽  
Climatic Factors ◽  
Age Groups ◽  
Absolute Humidity ◽  
Weather Conditions ◽  
Adverse Weather ◽  
Strong Negative Association ◽  
Lag Model ◽  
The Impact

This study was designed to explore the impact of meteorological factors (air temperature, relative and absolute humidity, wind, cloudiness and precipitation) on influenza morbidity in four selected big cities in Poland – Cracow, Poznań, Warsaw and Wrocław. Atmospheric data obtained from four meteorological stations spread over six years (2013‑2018) were compared to influenza-like illnesses (ILI) reports, obtained from the Voivodship Units of the State Sanitary Inspection for the same locations and period. Data were analysed using Spearman correlation and negative binomial regressions to capture the nonlinear relationship between exposure to environmental conditions and influenza morbidity. Our study found a strong negative association of absolute air humidity with influenza infections (RR = 0.738) and positive relationship with minimal temperature (RR = 1.148). The effect of wind speed, cloudiness and precipitation on ILI was less evident. Proposed model is valid for all age groups in Polish cities, but suits the best to elderly citizens (65+). The model is also appropriate for different seasons, however only absolute humidity, minimal temperature and wind speed are considered significant variables all year round. Furthermore, we observed 6 to 9-days delay between particular adverse weather conditions and ILI morbidity increase, as 1-week lag model proved to have the highest predictive power (AIC = 8644.97). Although meteorological variables have statistically significant contribution to explain influenza morbidity, there are also other non-climatic factors, that can possibly influence the seasonality and complexity of influenza epidemiology in Polish cities.

Modelling of 10 Gbps Free Space Optics Communication Link Using Array of Receivers in Moderate and Harsh Weather Conditions

2017 ◽  
Vol 38 (3) ◽  
Author(s):  
Amit Gupta ◽  
Nagpal Shaina
Keyword(s):  
Free Space ◽  
Weather Conditions ◽  
Quality Data ◽  
Laser Source ◽  
Communication Link ◽  
Free Space Optical ◽  
Space Optics ◽  
Received Power ◽  
Adverse Weather ◽  
The Impact

AbstractIntersymbol interference and attenuation of signal are two major parameters affecting the quality of transmission in Free Space Optical (FSO) Communication link. In this paper, the impact of these parameters on FSO communication link is analysed for delivering high-quality data transmission. The performance of the link is investigated under the influence of amplifier in the link. The performance parameters of the link like minimum bit error rate, received signal power and Quality factor are examined by employing erbium-doped fibre amplifier in the link. The effects of amplifier are visualized with the amount of received power. Further, the link is simulated for moderate weather conditions at various attenuation levels on transmitted signal. Finally, the designed link is analysed in adverse weather conditions by using high-power laser source for optimum performance.

Comparison of two gap-filling techniques for nitrous oxide fluxes from agricultural soil

2019 ◽  
Vol 99 (1) ◽  
pp. 12-24 ◽  
Author(s):  
Rezvan Taki ◽  
Claudia Wagner-Riddle ◽  
Gary Parkin ◽  
Rob Gordon ◽  
Andrew VanderZaag
Keyword(s):  
Missing Values ◽  
Interpolation Method ◽  
Weather Conditions ◽  
Linear Interpolation ◽  
Bias Error ◽  
Research Station ◽  
Ann Model ◽  
Gap Filling ◽  
Adverse Weather ◽  
The Impact

Micrometeorological methods are ideally suited for continuous measurements of N2O fluxes, but gaps in the time series occur due to low-turbulence conditions, power failures, and adverse weather conditions. Two gap-filling methods including linear interpolation and artificial neural networks (ANN) were utilized to reconstruct missing N2O flux data from a corn–soybean–wheat rotation and evaluate the impact on annual N2O emissions from 2001 to 2006 at the Elora Research Station, ON, Canada. The single-year ANN method is recommended because this method captured flux variability better than the linear interpolation method (average R2 of 0.41 vs. 0.34). Annual N2O emission and annual bias resulting from linear and single-year ANN were compatible with each other when there were few and short gaps (i.e., percentage of missing values <30%). However, with longer gaps (>20 d), the bias error in annual fluxes varied between 0.082 and 0.344 kg N2O-N ha−1 for linear and 0.069 and 0.109 kg N2O-N ha−1 for single-year ANN. Hence, the single-year ANN with lower annual bias and stable approach over various years is recommended, if the appropriate driving inputs (i.e., soil temperature, soil water content, precipitation, N mineral content, and snow depth) needed for the ANN model are available.

scholarly journals An Advanced Deep Learning Approach for Multi-Object Counting in Urban Vehicular Environments

2021 ◽  
Vol 13 (12) ◽  
pp. 306
Author(s):  
Ahmed Dirir ◽  
Henry Ignatious ◽  
Hesham Elsayed ◽  
Manzoor Khan ◽  
Mohammed Adib ◽  
...  
Keyword(s):  
Deep Learning ◽  
Intelligent Transportation Systems ◽  
Smart Cities ◽  
Weather Conditions ◽  
Research Area ◽  
Transportation Systems ◽  
Detection Accuracy ◽  
Adverse Weather ◽  
Object Counting ◽  
The Impact

Object counting is an active research area that gained more attention in the past few years. In smart cities, vehicle counting plays a crucial role in urban planning and management of the Intelligent Transportation Systems (ITS). Several approaches have been proposed in the literature to address this problem. However, the resulting detection accuracy is still not adequate. This paper proposes an efficient approach that uses deep learning concepts and correlation filters for multi-object counting and tracking. The performance of the proposed system is evaluated using a dataset consisting of 16 videos with different features to examine the impact of object density, image quality, angle of view, and speed of motion towards system accuracy. Performance evaluation exhibits promising results in normal traffic scenarios and adverse weather conditions. Moreover, the proposed approach outperforms the performance of two recent approaches from the literature.

Investigating the Impact of Rainfall on Travel Speed

2014 ◽  
Vol 71 (3) ◽  
Author(s):  
Nordiana Mashros ◽  
Johnnie Ben-Edigbe ◽  
Hashim Mohammed Alhassan ◽  
Sitti Asmah Hassan
Keyword(s):  
Empirical Studies ◽  
Heavy Rain ◽  
Weather Conditions ◽  
Travel Speed ◽  
Operating Conditions ◽  
Speed Reduction ◽  
Light Rain ◽  
Rainfall Condition ◽  
Adverse Weather ◽  
The Impact

The road network is particularly susceptible to adverse weather with a range of impacts when different weather conditions are experienced. Adverse weather often leads to decreases in traffic speed and subsequently affects the service levels. The paper is aimed at investigating the impact of rainfall on travel speed and quantifying the extent to which travel speed reduction occurs. Empirical studies were conducted on principle road in Terengganu and Johor, respectively for three months. Traffic data were collected by way of automatic traffic counter and rainfall data from the nearest raingauge station were supplied by the Department of Irrigation and Drainage supplemented by local survey data. These data were filtered to obtain traffic flow information for both dry and wet operating conditions and then were analyzed to see the effect of rainfall on percentile speeds. The results indicated that travel speed at 15th, 50th and 85th percentiles decrease with increasing rainfall intensities. It was observed that allpercentile speeds decreased from a minimum of 1% during light rain to a maximum of 14% during heavy rain. Based on the hypothesis that travel speed differ significantly between dry and rainfall condition; the study found substantial changes in percentile speeds and concluded that rainfalls irrespective of their intensities have significant impact on the travel speed.

Effectiveness of Predictive Weather-Related Active Transportation and Demand Management Strategies for Network Management

2017 ◽  
Vol 2667 (1) ◽  
pp. 71-87 ◽  
Author(s):  
Zihan Hong ◽  
Hani S. Mahmassani ◽  
Xiang Xu ◽  
Archak Mittal ◽  
Ying Chen ◽  
...  
Keyword(s):  
Traffic Management ◽  
Demand Management ◽  
Management Strategies ◽  
Weather Conditions ◽  
Active Transportation ◽  
Operational Conditions ◽  
Traffic Conditions ◽  
Adverse Weather ◽  
Traffic Performance ◽  
The Impact

This paper presents the development, implementation, and evaluation of predictive active transportation and demand management (ATDM) and weather-responsive traffic management (WRTM) strategies to support operations for weather-affected traffic conditions with traffic estimation and prediction system models. First, the problem is defined as a dynamic process of traffic system evolution under the impact of operational conditions and management strategies (interventions). A list of research questions to be addressed is provided. Second, a systematic framework for implementing and evaluating predictive weather-related ATDM strategies is illustrated. The framework consists of an offline model that simulates and evaluates the traffic operations and an online model that predicts traffic conditions and transits information to the offline model to generate or adjust traffic management strategies. Next, the detailed description and the logic design of ATDM and WRTM strategies to be evaluated are proposed. To determine effectiveness, the selection of strategy combination and sensitivity of operational features are assessed with a series of experiments implemented with a locally calibrated network in the Chicago, Illinois, area. The analysis results confirm the models’ ability to replicate observed traffic patterns and to evaluate the system performance across operational conditions. The results confirm the effectiveness of the predictive strategies tested in managing and improving traffic performance under adverse weather conditions. The results also verify that, with the appropriate operational settings and synergistic combination of strategies, weather-related ATDM strategies can generate maximal effectiveness to improve traffic performance.

Effect of Median Design on Rural Freeway Safety

2008 ◽  
Vol 2060 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Andrew P. Tarko ◽  
Natalie M. Villwock ◽  
Nicolas Blond
Keyword(s):  
Opposite Direction ◽  
Negative Binomial ◽  
Prediction Models ◽  
Negative Binomial Regression ◽  
Well Being ◽  
Crash Severity ◽  
Before And After ◽  
Single Vehicle ◽  
Median Width ◽  
The Impact

Although median barriers are an absolute means of preventing drivers from crossing road medians and colliding with vehicles moving in the opposite direction, they may cause additional crashes. This perhaps complex safety effect of median barriers has not been investigated well. Being able to predict the safety impact of most types of median barriers on rural freeways is becoming more desirable because some state departments of transportation plan to expand many of their four-lane rural freeways to six lanes to accommodate increases in traffic volume. Realistic crash prediction models sensitive to the median design would provide the needed guidance useful in designing adequate median treatments on widened freeways. The impact of median designs on crash frequency was investigated in this study through negative binomial regression and before-and-after studies based on data collected in eight participating states. The impact on crash severity was investigated with a logit model. The separate effects of changes in median geometry were quantified for single-vehicle, multiple-vehicle same direction, and multiple-vehicle opposite direction crashes. The results were significantly different and indicated that reducing the median width without adding barriers (the remaining median width is still reasonably wide) increases the severity of crashes, particularly opposite direction crashes. Further, reducing the median and installing concrete barriers eliminates opposite direction crashes but doubles the frequency of single-vehicle crashes and tends to lessen the frequency of same direction crashes. The crash severity also tends to increase.

scholarly journals Cardiovascular risk assessment of the population under adverse weather conditions

2020 ◽  
Vol 99 (5) ◽  
pp. 488-492
Author(s):  
R. B. Tsallagova ◽  
O. I. Kopytenkova ◽  
Fatima K. Makoeva ◽  
A. R. Nanieva
Keyword(s):  
Negative Impact ◽  
Adult Population ◽  
Medical Science ◽  
Weather Conditions ◽  
Air Pressure ◽  
Medical Documentation ◽  
Atmospheric Air ◽  
Adverse Weather ◽  
The Impact ◽  
The City

Introduction. Climate change around the world determines the relevance of the study of its effects on the human health. Nowadays, due to the development of modern medical science, the methods of evidence-based analysis of negative impact of the environmental factors on the public health are being widely implemented into preventive medicine. Their use should make it possible to quantify the various risks with high confidence and to manage them effectively. Material and methods. The weather conditions of the territory of Vladikavkaz for a 15-years period (2001-2015) have been studied. On the basis of the data from the primary medical documentation of emergency medical care (EMC) for the same period, the health status of the adult population in the city has been studied. The impact of the meteorological elements under the study on the frequency of seeking EMC was estimated using the relative (RR) and population risks (Rpop) values. Results. For the city of Vladikavkaz (according to the medical classification of weather conditions), high air humidity is typical for 65% of the days in a year, low air velocity (less than 3 m/s) - 77% of the days in a year. Inter-day fluctuations in temperature and atmospheric air pressure, exceeding the optimal levels for the human body, are recorded more than in 30% of the days in a year. Discussion. The city of Vladikavkaz is characterized by windless, wet weather, with frequent inter-day fluctuations in temperature and atmospheric air pressure, which corresponds to the clinically irritating and acute types of weather. Conclusion. The calculations of the relative and the population risks of impact of meteorological changes on the developing of urgent cardiovascular conditions in the population of Vladikavkaz showed RR of combining two unfavourable weather factors to be of 1.081 (p <0.0001), and the Rpop increases by more than 3600 additional EMC calls due to cardiovascular pathology.

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