scholarly journals Differences between day and night pedestrian-injury severities: Accounting for temporal and unobserved effects in prediction

2021 ◽  
pp. 100201
Author(s):  
Asim Alogaili ◽  
Fred Mannering
Keyword(s):  
Pedestrian Injury ◽  
Unobserved Effects ◽  
Injury Severities

Pedestrian Injury Severities in Pedestrian-Vehicle Crashes and the Partial Proportional Odds Logit Model: Accounting for Age Difference

2019 ◽  
Vol 2673 (5) ◽  
pp. 731-746 ◽  
Author(s):  
Yang Li ◽  
Wei (David) Fan
Keyword(s):  
Logit Model ◽  
Injury Severity ◽  
Parameter Estimates ◽  
Age Difference ◽  
Age Group ◽  
Vehicle Crashes ◽  
Ordered Logit ◽  
Proportional Odds ◽  
Pedestrian Injury ◽  
Injury Severities

This study investigates factors that significantly contribute to the severity of pedestrian injuries resulting from pedestrian-vehicle crashes. Multinomial logit (MNL) models, mixed logit (ML) models, and ordered logit/probit models have been widely used in modeling crash injury severity, including pedestrian injury severity in pedestrian-vehicle crashes. However, both MNL and ML models treat injury severity levels as non-ordered, ignoring the inherent hierarchical nature of crash injury severities, and the data used in ordered logit models need to be strictly subjected to the proportional odds (PO) assumption. In this study, a partial proportional odds (PPO) logit model approach is employed to explore the issues of pedestrian safety associated with each age group: young (aged under 24), middle-aged (aged 25–55), and older pedestrians (aged over 55). Data used in this study are police-reported pedestrian crash data collected from 2007 to 2014 in North Carolina. A variety of motorist, pedestrian, environmental, and roadway characteristics are inspected. Results from likelihood ratio tests statistically show the better performance of developing separate injury severity models for each age group compared with estimating a single model utilizing all data. Relevant parameter estimates and associated marginal effects are used to interpret the results, followed by recommendations made in the concluding section.

A Numerical Study on Pedestrian Kinematics and Injury Parameters in Bus Collisions

2014 ◽  
Vol 945-949 ◽  
pp. 35-39
Author(s):  
Shu Jing Zhao ◽  
Li Li ◽  
Fang Wang ◽  
Ji Kuang Yang
Keyword(s):  
Injury Risk ◽  
Numerical Study ◽  
Travel Speed ◽  
Design Parameters ◽  
Parameter Study ◽  
Initial State ◽  
Pedestrian Injury ◽  
Injury Severities ◽  
Multi Body ◽  
The Impact

This paper aimed at investigating the injury risk and the kinematics of pedestrians in collisions with buses. A mathematical model of a production bus was developed. A parameter study of the bus-pedestrian collision was carried out by using the bus MB (multi-body model) and a validated pedestrian MB model in terms of pedestrian postures, bus front design parameters, and different impact conditions. The results indicated that the initial state of pedestrians has significant influences on their kinematic responses. The impact speed and front stiffness has remarkable effects on pedestrian injury severities. Besides, restricted bus travel speed,lowered stiffness of bus front structure and reduced ground clearance could reduce the pedestrian injury risks.

Modeling Pedestrian Injury Severity in Pedestrian-Vehicle Crashes in Rural and Urban Areas: Mixed Logit Model Approach

2019 ◽  
Vol 2673 (4) ◽  
pp. 1023-1034 ◽  
Author(s):  
Zhen Chen ◽  
Wei (David) Fan
Keyword(s):  
Urban Areas ◽  
Injury Severity ◽  
Mixed Logit ◽  
Speed Limit ◽  
Vehicle Crashes ◽  
Dark Light ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
Pedestrian Injury ◽  
Injury Severities

Pedestrian-vehicle crashes are more likely to result in severe pedestrian incapacitating injuries and fatalities than other types of crashes. In this study, mixed logit models are developed to investigate and identify significant contributing factors to the pedestrian injury severity in pedestrian-vehicle crashes in both rural and urban areas in North Carolina, United States. Pedestrian-vehicle crash data from the Highway Safety Information System database from 2005 to 2012 are collected and used in this study. Crash injury severities are classified into five categories: fatality; injury class 1 (disabling injury); injury class 2 (evident injury); injury class 3 (possible injury); and no injury (property damage only). The estimation results show that factors such as a bad driver’s physical condition, heavy trucks, dark light condition, speed limit between 35 and 50 mph and speed limit above 50 mph will significantly increase pedestrian injury severities in both rural and urban areas. The developed model and analysis results provide insights on developing effective countermeasures to reduce pedestrian injury severities in pedestrian-vehicle crashes and improve traffic system safety performance.

scholarly journals The effects of health shocks on family status: do financial incentives encourage marriage?

2021 ◽  
Author(s):  
Andree Ehlert
Keyword(s):  
Financial Incentives ◽  
Economic Benefits ◽  
Health Shocks ◽  
Family Status ◽  
Female Partners ◽  
Political Implications ◽  
Financial Benefits ◽  
German Socioeconomic Panel ◽  
Unobserved Effects ◽  
Traditional Marriage

AbstractThis paper asks whether marriage decisions of unmarried mature couples are driven by the prospect of financial advantages for the later widowed after one partner has suffered a serious health shock. We hypothesize that, in contrast to traditional marriage models, such health shocks may induce unmarried couples to obtain economic benefits, such as survivors’ pensions in particular, through marriage in advance of one partner’s death. This question has not yet been studied empirically. Hazard models capturing unobserved effects are applied to longitudinal data of the German Socioeconomic Panel. It turns out that the probability of marriage after male partners’ health shocks can increase significantly depending on the amount of expected survivors’ pensions for the (likely) surviving female partners. In contrast, an increased probability of marriage after health shocks to women (depending on the expected financial benefits to men) was not found. These findings are supported by various robustness checks. Economic and political implications are discussed and the results are placed in an international context.

Analysis of Single-Vehicle Crash Injury Severities in Urban River-Crossing Road Tunnels

2015 ◽  
Vol 743 ◽  
pp. 526-532 ◽  
Author(s):  
C.M. Jiang ◽  
J.J. Lu ◽  
L.J. Lu
Keyword(s):  
Heavy Vehicles ◽  
Probit Regression ◽  
Factors Affecting ◽  
Explanatory Variables ◽  
Urban Road ◽  
Road Tunnels ◽  
Negative Effect ◽  
Single Vehicle ◽  
Injury Severities ◽  
One Year

Based on the originally unprocessed data from the Official Platform of“110”Alarming Receiving Center (OP110ARC) of Shanghai Public Security Bureau (SPSB), 529 single-vehicle crashes reported during one year and a half which happened at the thirteen urban road tunnels going across the Huangpu River are used in this study. To investigate the factors affecting the crash influence severity levels, ordered probit regression is established. Several categories of factors are considered as explanatory variables in the models. The study finds that the entrance of the tunnels is the site where severe injury crashes trend to occur. Rainy and snowy days impose vehicles and motorists driving via the tunnel sections in danger. Tunnels with a low speed limit (40 km/h in this study) may be not as safe as we thought before. Two-wheel vehicles without sufficient physical protection for its drivers and heavy vehicles also show a negative effect on the operation safety of single-vehicle at these studied tunnels. Alcohol involved drivers are more likely to suffer from a severe crashes and gets badly hurt.

Examining Driver Injury Severity in Single-Vehicle Road Departure Crashes Involving Large Trucks

2021 ◽  
pp. 036119812110101
Author(s):  
Mehdi Hosseinpour ◽  
Kirolos Haleem
Keyword(s):  
Rural Areas ◽  
Injury Severity ◽  
Factors Affecting ◽  
Crash Data ◽  
Natural Logarithm ◽  
Concrete Barriers ◽  
Local Roads ◽  
Single Vehicle ◽  
Safety Countermeasures ◽  
Injury Severities

Road departure (RD) crashes are among the most severe crashes that can result in fatal or serious injuries, especially when involving large trucks. Most previous studies neglected to incorporate both roadside and median hazards into large-truck RD crash severity analysis. The objective of this study was to identify the significant factors affecting driver injury severity in single-vehicle RD crashes involving large trucks. A random-parameters ordered probit (RPOP) model was developed using extensive crash data collected on roadways in the state of Kentucky between 2015 and 2019. The RPOP model results showed that the effect of local roadways, the natural logarithm of annual average daily traffic (AADT), the presence of median concrete barriers, cable barrier-involved collisions, and dry surfaces were found to be random across the crash observations. The results also showed that older drivers, ejected drivers, and drivers trapped in their truck were more likely to sustain severe single-vehicle RD crashes. Other variables increasing the probability of driver injury severity have included rural areas, dry road surfaces, higher speed limits, single-unit truck types, principal arterials, overturning-consequences, truck fire occurrence, segments with median concrete barriers, and roadside fixed object strikes. On the other hand, wearing seatbelt, local roads and minor collectors, higher AADT, and hitting median cable barriers were associated with lower injury severities. Potential safety countermeasures from the study findings include installing median cable barriers and flattening steep roadside embankments along those roadway stretches with high history of RD large-truck-related crashes.

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