Assessing factors causing severe injuries in crashes of high-deck buses in long-distance driving on freeways

High-deck buses that have a higher center of gravity traveling at an excessive speed have a higher likelihood of causing serious and fatal accidents when drivers lose control of the vehicle. In addition, drivers who suffer from fatigue in long-distance driving increase the likelihood of serious accident. This paper examines the effects of risk factors contributing to severe crashes associated with high-deck buses used for long-distance driving on freeways. An ordered logit and latent class models are used to examine significant factors on the severity of injuries in crashes related to high-deck buses. Driver fatigue, drivers or passengers not wearing a seat belt, reckless driving, drunk driving, crashes occurred between midnight and dawn, and crashes occurred at interchange ramps were found to significantly affect the severity of injuries in crashes involving high-deck buses. Safety policies to prevent severe injuries in crashes involving high deck buses used for long-distance runs on freeways include: (1) restricting drivers from exceeding the limit of daily driving hours and mandating sufficient rest breaks; (2) installing an automatic sleep-warning device in the vehicle; (3) drivers with obstructive sleep apnea syndrome or sleep disorders should be tested and treated before they are allowed to perform long hours of driving tasks; (4) educating the public or even amending the seatbelt legislation to require all passengers to wear a seat belt and thus reduce the chance of ejection from a high-deck bus and prevent serious injuries in a crash while traveling at a higher speed on freeways.     

Effect of bus size and operation to crash occurrences

This paper evaluates roadway and operational factors considered to influence crashes involving buses. Factors evaluated included those related to bus sizes and operation services. Negative binomial (NB) and multinomial logit (MNL) models were used in linearizing and quantifying these factors with respect to crash frequency and injury severities, respectively. The results showed that position of the bus travel lane, presence or absence of on-street shoulder parking, posted speed limit, lane width, median width, number of lanes per direction and number of vehicles per lane has a higher influence on bus crashes compared to other roadway and traffic factors. Wider lanes and medians were found to reduce probability of bus crashes while more lanes and higher volume per lane were found to increase the likelihood of occurrences of bus-related crashes. Roadways with higher posted speed limits excluding freeways were found to have high probability of crashes compared to low speed limit roadways. Buses traveling on the inner lanes and making left turns were found to have higher probability of crashes compared to those traveling on the right most lanes. The same factors were found to influence injury severity though with varying magnitudes compared to crash frequency.     

Incidence and characteristics of school bus crashes and injuries

Objective

Studies of school bus crashes have focused on the biomechanics of catastrophic collisions, with very few examining crash incidence.

Methods

Crashes in the state of Iowa were examined from January 2002 through December 2005. School bus crashes were identified through the Iowa Crash Data, a comprehensive database of all reported crashes in the State of Iowa. School bus mileage data were provided by the Iowa Department of Education. School bus crash, fatality, and injury rates were calculated and differences in crash and injury characteristics between school buses and other vehicles were examined.

Results

The school bus crash, fatality and non-fatal injury rates were 320.7, 0.4 and 13.6 per 100 million bus miles travelled, respectively. School bus crash fatality and injury rates were 3.5 and 5.4 times lower than overall all vehicle crash fatality and injury rates, respectively. Drivers of other vehicles were more likely to have caused the crash than the bus driver (P < 0.001).

Conclusions

School buses experience low crash rates, and the majority of crashes do not lead to injury. Buses are among the safest forms of road transportation, and efforts to educate drivers of other vehicles may help reduce crashes with buses.     

Bus accident analysis of routes with/without bus priority

This paper summarises findings on road safety performance and bus-involved accidents in Melbourne along roads where bus priority measures had been applied. Results from an empirical analysis of the accident types revealed significant reduction in the proportion of accidents involving buses hitting stationary objects and vehicles, which suggests the effect of bus priority in addressing manoeuvrability issues for buses. A mixed-effects negative binomial (MENB) regression and back-propagation neural network (BPNN) modelling of bus accidents considering wider influences on accident rates at a route section level also revealed significant safety benefits when bus priority is provided. Sensitivity analyses done on the BPNN model showed general agreement in the predicted accident frequency between both models. The slightly better performance recorded by the MENB model results suggests merits in adopting a mixed effects modelling approach for accident count prediction in practice given its capability to account for unobserved location and time-specific factors. A major implication of this research is that bus priority in Melbourne's context acts to improve road safety and should be a major consideration for road management agencies when implementing bus priority and road schemes.     

Crash and safety assessment program for paratransit buses

This paper describes an assessment program for paratransit buses concerning their crashworthiness and safety of passengers. The program developed by the authors was approved by the Transit Office of the Florida Department of Transportation as a part of the Florida Vehicle Procurement Program (FVPP) in August 2007. Several valuable, worldwide vehicle safety standards were adopted in it with modifications addressing the bus construction process and relevance of particular structural components in crash events. Passenger compartment structure, which needs to be protected against the most dangerous accidents such as a side impact and a rollover, is a major area of concern in the standard. Lack of such standards may result in poor crashworthiness characteristics of the bus structure and in severe injuries and possible passenger fatalities. Either full-scale experiments or numerical standardized simulations were proposed as equivalent approval methods for paratransit buses. Selected results for partially validated Finite Element (FE) models and the nonlinear explicit dynamic code LS-DYNA were used to demonstrate a numerical approach for a bus structure approval. The FE models can also be used to assist the bus manufacturer in an effort to improve the crashworthiness of the new bus designs. The procedure described in this paper was implemented to monitor crashworthiness resistance of the paratransit buses distributed and operated in the state of Florida.     

Crashworthiness assessment of a paratransit bus

Most of the bus safety standards in the USA are not applicable to cutaway buses for which a production process is split into two stages. First, the chassis and cab section are assembled by automobile manufactures. Then the vehicle is shipped to another company, where bus body and additional equipment are installed. Lack of strict structural standards for transit bus body builders stimulates the need for crashworthiness and safety evaluation for this category of vehicles.This study focused on a selected transit bus, the Ford Eldorado Aerotech 240. Due to the lack of design data the reverse engineering process was used to acquire the geometric data of the bus. The finite element (FE) model was developed based on the geometry obtained by disassembling and digitizing all major parts of the actual bus.The FE model consists of 73,600 finite elements, has 174 defined properties (groups of elements with the same features) and 23 material models. LS-DYNA non-linear, explicit, 3-D, dynamic FE computer code was used to simulate behavior of the FE model under different impact scenarios, such as front impact and side impact of two buses at various velocities.     

Passenger car collision fatalities--with special emphasis on collisions with heavy vehicles

Between 1995 and 2004, 293 passenger car occupants died in collisions with other vehicles in northern Sweden (annual incidence: 3.3 per 100,000 inhabitants, 6.9 per 100,000 cars, or 4.8 per 10(9)km driven); half of these deaths involved heavy vehicles. The annual number of passenger car occupant deaths per 100,000 cars in car-truck/bus collisions has remained unchanged since the 1980s, but in car-car collisions it has decreased to one third of its former level. As crash objects, trucks and buses killed five times as many car occupants per truck/bus kilometer driven as did cars. The collisions were characterized by crashes in the oncoming vehicle's lane, under icy, snowy, or wet conditions; crashes into heavy vehicles generally occurred in daylight, on workdays, in winter, and on 90 and 70 km/h two-lane roads. Head and chest injuries accounted for most of the fatal injuries. Multiple fatal injuries and critical and deadly head injuries characterized the deaths in collisions with heavy vehicles. An indication of suicide was present in 4% of the deaths; for those who crashed into trucks, this percentage was doubled. Among the driver victims, 4% had blood alcohol levels above the legal limit of 0.2g/L. Frontal collision risks might be reduced by a mid-barrier, by building less injurious fronts on trucks and buses, by efficient skid prevention, and by use of flexible speed limits varying with road and light conditions.     

基于用户需求的宜老型公交倚靠设施设计研究

目的在人口老龄化的背景下,基于用户需求对宜老型公交倚靠设施进行设计,优化老年人的出行体验。方法针对现有公交车辆上存在的问题,结合老年人关节僵硬和下肢肌肉力量不足等情况,帮助老年人在车内平稳站立。依据研究结论,对公交车上的倚靠设施提出新的设想,并使用层次分析法进行评估。结论通过研究用户对公交倚靠设施的使用体验,分析老年乘客在不同评价维度上对于设计思路的信任感和认可度,以此满足老年乘客对宜老型公交倚靠设施的需求。     

Safety evaluation of multilane arterials in Florida

Resurfacing is one of the more common construction activities on highways. While its effect on riding quality on any type of roadway is obviously positive; its impact on safety as measured in terms of crashes is far from obvious. This study examines the safety effects of the resurfacing projects on multilane arterials with partially limited access. Empirical Bayes method, which is one of the most accepted approaches for conducting before-after evaluations, has been used to assess the safety effects of the resurfacing projects. Safety effects are estimated not only in terms of all crashes but also rear-end as well as severe crashes (crashes involving incapacitating and fatal injuries). The safety performance functions (SPFs) used in this study are negative binomial crash frequency estimation models that use the information on ADT, length of the segments, speed limit and number of lanes. These SPFs are segregated by crash groups (all, rear-end, and severe), length of the segments being evaluated, and land use (urban, suburban, and rural). The results of the analysis show that the resulting changes in safety following resurfacing projects vary widely. Evaluating additional improvements carried out with resurfacing activities showed that all (other than sidewalk improvements for total crashes) of them consistently led to improvements in safety of multilane arterial sections. It leads to the inference that it may be a good idea to take up additional improvements if it is cost effective to do them along with resurfacing. It was also found that the addition of turning lanes (left and/or right) and paving shoulders were two improvements associated with a project's relative performance in terms of reduction in rear-end crashes.     

Is there a pattern in European bus and coach incidents? A literature analysis with special focus on injury causation and injury mechanisms

In order to identify and describe a pattern in bus and coach incident related injuries and fatalities, and to suggest possible future measures for improvement of bus and coach safety, a literature analysis was performed. The results formed a multi-faceted pattern, which briefly can be described as follows; women travelled more frequently by bus as compared to men. Injuries sustained predominantly affected women 60 years of age and older. Of all traffic fatalities in Europe, bus and coach fatalities represented 0.3-0.5%. In the OECD countries, the risk of being killed or seriously injured was found to be seven to nine times lower for bus and coach occupants as compared to those of car occupants. Despite the fact that fatalities were more frequent on rural roads, a vast majority of all bus and coach casualties occurred on urban roads and in dry weather conditions. Boarding and alighting caused about one-third of all injury cases. Collisions were a major injury-contributing factor. Buses and coaches most frequently collided with cars, but unprotected road users were hit in about one-third of all cases of a collision, the point of impact on the bus or the coach being typically frontal or side. Rollovers occurred in almost all cases of severe coach crashes. In this type of crash projection, total ejection, partial ejection, intrusion and smoke inhalation were the main injury mechanisms and among those, ejection being the most dangerous. A 2-point belt may prevent passenger ejection, but in frontal crashes when the upper abdominal parts and the head hit the seatback in front, it could, however, contribute to head and thoracic injuries. Hence, a 3-point belt provides the best restraint in rollovers and frontal crashes.     

Risky behavior of bus commuters and bus drivers in Karachi, Pakistan.

Buses account for a disproportionate number of road traffic accident fatalities in Karachi, Pakistan and other developing countries. Potentially dangerous bus driving and commuting practices that increase risk of road accidents and the effect of traffic police on bus behavior are evaluated. A total of 250 episodes each of disembarking and embarking commuters, buses stopping and moving on the road at ten of Karachi's highest risk intersections for traffic injuries were observed. Of the disembarking passengers, 33% did not wait for the bus to stop; 54% stepped off in the center of the road and 84% did not look out for traffic. Among the embarking commuters, 38% got on moving buses; 73% climbed on buses filled to their outer foot boards and 83% waited for buses on the street. Males were more likely than females to jump off a moving bus (43% versus 1.6%, P < 0.001), get on a moving bus (49% versus 12%, P < 0.001), and run to catch a bus (45% versus 8%, P < 0.001). At the bus stops, 30% of the buses did not stop completely; 46% stopped away from the stop and 79% stopped in the center of the road. Where traffic police were present buses were more likely to race (9% versus 3%, P = 0.05) and to cut off other vehicles (13% versus 2%, P = 0.001) than where police were absent. Risky behavior is common among both Karachi bus drivers and bus commuters. The traditional efforts to regulate bus traffic through traffic police is ineffective.     

An empirical analysis of farm vehicle crash injury severities on Iowa's public road system

Farm vehicle crashes are a major safety concern for farmers as well as all other users of the public road system in agricultural states. Using data on farm vehicle crashes that occurred on Iowa's public roads between 2004 and 2006, we estimate a multinomial logit model to identify crash-, farm vehicle-, and driver-specific factors that determine farm vehicle crash injury severity outcomes. Estimation findings indicate that there are crash patterns (rear-end manner of collision; single-vehicle crash; farm vehicle crossed the centerline or median) and conditions (obstructed vision and crash in rural area; dry road, dark lighting, speed limit 55 mph or higher, and harvesting season), as well as farm vehicle and driver-contributing characteristics (old farm vehicle, young farm vehicle driver), where targeted intervention can help reduce the severity of crash outcomes. Determining these contributing factors and their effect is the first step to identifying countermeasures and safety strategies in a bid to improve transportation safety for all users on the public road system in Iowa as well as other agricultural states.     

A bi-objective optimization approach for exclusive bus lane selection and scheduling design

This study proposes a methodology to solve the integrated problems of selection and scheduling of the exclusive bus lane. The selection problem intends to determine which roads (links) should have a lane reserved for buses while the scheduling problem intends to find the time period of the application. It is formulated as a bi-objective optimization model that aims to minimize the total travel time of non-bus traffic and buses simultaneously. The proposed model formulation is solved by the hybrid non-dominated sorting genetic algorithm with Paramics. The results show that the proposed methodology is workable. Sets of Pareto solutions are obtained indicating that a trade-off between buses and non-bus traffic for the improvement of the bus transit system is necessary when the exclusive bus lane is applied. This allows the engineer to choose the best solutions that could balance the performance of both modes in a multimode transport system environment to achieve a sustainable transport system.     

基于路况适配下的城市专用校车造型设计

目的以满足我国儿童对专用校车安全性及舒适性的需求为目标,使其在符合我国城市路况环境的基础上,探索具有高度适配性的儿童专用校车设计方法和实践路径。方法通过对儿童行为及心理需求的分析,把握专用校车外观、内饰及车身附件的设计要素及实践方向,并分析路面状况、交通状况、道路规格等因素对于校车设计产生的影响,明确儿童专用校车的设计痛点和趋向目标。结果在系统分析了人、环境、车3种基本要素的基础上,依据设计方法及实践路径,开展儿童专用校车的外观及内饰设计,通过需求内涵的转译、美学要素的传达使设计实践结果达到了最终目标。结论儿童专用校车要综合考虑儿童心理、行为要素、环境系统等专用特种车特点,使其能够符合国情、国民特征,具备时代性和发展性。     

军用ATS测试总线技术的现状与发展趋势

总线技术,特别是外部总线技术在装备自动测试系统(ATS)中占有十分重要的地位,是构成装备自动测试系统的桥梁与纽带.本文较为详细地介绍了现有军用ATS中常用的几种外部总线,并对主要外部总线的性能进行了比较;对军用ATS外部总线技术的发展趋势进行了展望,指出带热插拔功能的USB总线及满足高吞吐量、长传输距离的总线将成为未来总线发展的趋势.     

Analysis of factors associated with injury severity in crashes involving young New Zealand drivers

Young people are a risk to themselves and other road users, as motor vehicle crashes are the leading cause of their death. A thorough understanding of the most important factors associated with injury severity in crashes involving young drivers is important for designing well-targeted restrictive measures within youth-oriented road safety programs. The current study estimates discrete choice models of injury severity of crashes involving young drivers conditional on these crashes having occurred. The analysis examined a comprehensive set of single-vehicle and two-vehicle crashes involving at least one 15–24 year-old driver in New Zealand between 2002 and 2011 that resulted in minor, serious or fatal injuries. A mixed logit model accounting for heterogeneity and heteroscedasticity in the propensity to injury severity outcomes and for correlation between serious and fatal injuries proved a better fit than a binary and a generalized ordered logit. Results show that the young drivers’ behavior, the presence of passengers and the involvement of vulnerable road users were the most relevant factors associated with higher injury severity in both single-vehicle and two-vehicle crashes. Seatbelt non-use, inexperience and alcohol use were the deadliest behavioral factors in single-vehicle crashes, while fatigue, reckless driving and seatbelt non-use were the deadliest factors in two-vehicle crashes. The presence of passengers in the young drivers’ vehicle, and in particular a combination of males and females, dramatically increased the probability of serious and fatal injuries. The involvement of vulnerable road users, in particular on rural highways and open roads, considerably amplified the probability of higher crash injury severity.     

The effects of electronic stability control (ESC) on crashes--an update

The present study is an update of the meta-analysis by Erke (Erke, A., 2008. Effects of Electronic Stability Control (ESC) on accidents: a review of empirical evidence. Accident Analysis & Prevention, 40 (1), 167–173). Results from 12 studies of the effects of Electronic Stability Control (ESC) on the number of different types of crashes were summarized by means of meta-analysis. The results indicate that ESC prevents about 40% of all crashes involving loss of control. The greatest reductions were found for rollover crashes (−50%), followed by run-off-road (−40%) and single vehicle crashes (−25%). These results are however likely to be somewhat overestimated, especially for non-fatal crashes. Multiple vehicle crashes were found to be largely unchanged. Reductions were found for some types of multiple vehicle crashes. Rear-end collisions are unchanged or may increase. Fatal crashes involving pedestrians, bicycles or animals were found to increase as well. ESC was found to be more effective in preventing fatal crashes than non-fatal crashes. ESC is often found to be more effective in Sports Utility Vehicles (SUVs) than in passenger cars. This may be due to differences between drivers of SUVs and passenger cars. The results from meta-analysis indicate that drivers of ESC-equipped vehicles are likely to be safer drivers than other drivers. All the same, ESC may lead to behavioural adaptation in some cases, but it is not likely that behavioural adaptation offsets the positive safety effects. This may be due to a lack of knowledge about ESC.     

Factors affecting the probability of bus drivers being at-fault in bus-involved accidents

Previous research has provided little insight into factors that influence the probability of bus drivers being at-fault in bus-involved accidents. In this study, an analysis was conducted on accident data compiled by a bus company that include an assessment on whether the bus driver was deemed by the company to hold primary responsibility for accident occurrence. Using a mixed logit modelling approach, roadway/environmental, vehicle and driver related variables that were identified to be influential were road type, speed limit, traffic/lighting conditions, bus priority, bus age/length and driver's age/gender/experience/historic at-fault accident record. Results were indicative of possible confined road-space issues that bus drivers face along routes with roadside traffic friction and point to the provision of exclusive right of way for buses as a possible way to address this. Results also suggest benefits in assigning routes comprising mainly divided roads as well as newer and shorter buses to less experienced drivers.     

Cost savings from a sustained compulsory breath testing and media campaign in New Zealand

This paper evaluates three approaches to compulsory breath testing (CBT) where all drivers stopped are tested: (1) intensive, moderate-profile CBT (plus zero alcohol tolerance for drivers under age 20, which was implemented simultaneously, remains in effect, and unavoidably is commingled with CBT in the effectiveness estimates); (2) CBT plus an enhanced media campaign; and (3) shifting to aggressively visible booze buses, which also streamlined drunk-driver processing, plus enhanced community campaigns against drunk-driving. Approaches 1 and 2 were implemented throughout New Zealand (NZ) in 1993 and 1995. Booze buses and community programs were added for about one-third of the country in late 1996. ARIMA time series models estimated the impact on serious and fatal injury crashes between 10 p.m. and 3 a.m., a proxy for alcohol-related crashes. A benefit-cost analysis assessed return on investment. Cost savings were analyzed from four perspectives: societal, governmental, drunk-drivers', and people other than drunk-drivers (external cost). CBT plus zero tolerance reduced expected night-time crashes by 22.1% and enhanced media by 13.9%. Booze buses yielded a further 27.4% reduction where implemented. The program and associated crash reduction persisted until at least 2001 (the most recent data available). Estimated societal benefit-cost ratios were 14 for CBT, 19 for CBT plus enhanced media, and 26 for the comprehensive package. Government saved more than it spent on the program, especially with booze buses. Aggressive CBT plus zero alcohol tolerance for youth, media blitzes, and booze buses proved dramatically effective. Together, these four interventions halved late night serious and fatal injury crashes. Sustained effort seems to be critical. Better outcomes may be achieved with staged, increasingly visible and inescapable checkpoints than with an "ideal" initial program. It appears CBT is best implemented in conjunction with broader community-centered efforts to reduce drunk-driving.