城际客运专线通过能力研究

根据城际客运专线开行大站停和站站停列车特点，确定城际客运专线通过能力是在给定大站停列车数量上放行站站停列车能力来计算的。由于各类车存在速差，以及停站越行方案不同都会产生站站停列车扣除大站停列车，为此引入各类列车及列车组扣除系数计算城际客运专线通过能力，为保证扣除系数准确性对各类列车的分布作概率分析。最后得出了计算城际客运专线通过能力的算法和公式，并给出算例说明和辅以计算机编图验证其结论。     

秦沈客运专线工程建设办公信息系统的安全设计

从秦沈客运专线工程建设办公信息系统的网络和系统内部安全机制出发 ,提出了大型交通工程项目办公自动化系统信息安全技术的理论和设计思路。系统而成功的运行为今后同类项目的安全设计提供了一种新的思路并有一定的参考价值。     

Constrained Laboratory vs. Unconstrained Steering-Induced Rollover Crash Tests

Objective: The goal of this study was to evaluate how well an in-laboratory rollover crash test methodology that constrains vehicle motion can reproduce the dynamics of unconstrained full-scale steering-induced rollover crash tests in sand.

Methods: Data from previously-published unconstrained steering-induced rollover crash tests using a full-size pickup and mid-sized sedan were analyzed to determine vehicle-to-ground impact conditions and kinematic response of the vehicles throughout the tests. Then, a pair of replicate vehicles were prepared to match the inertial properties of the steering-induced test vehicles and configured to record dynamic roof structure deformations and kinematic response.

Results: Both vehicles experienced greater increases in roll-axis angular velocities in the unconstrained tests than in the constrained tests; however, the increases that occurred during the trailing side roof interaction were nearly identical between tests for both vehicles. Both vehicles experienced linear accelerations in the constrained tests that were similar to those in the unconstrained tests, but the pickup, in particular, had accelerations that were matched in magnitude, timing, and duration very closely between the two test types. Deformations in the truck test were higher in the constrained than the unconstrained, and deformations in the sedan were greater in the unconstrained than the constrained as a result of constraints of the test fixture, and differences in impact velocity for the trailing side.

Conclusions: The results of the current study suggest that in-laboratory rollover tests can be used to simulate the injury-causing portions of unconstrained rollover crashes. To date, such a demonstration has not yet been published in the open literature. This study did, however, show that road surface can affect vehicle response in a way that may not be able to be mimicked in the laboratory. Lastly, this study showed that configuring the in-laboratory tests to match the leading-side touchdown conditions could result in differences in the trailing side impact conditions.     

Evaluating the Effect of a Mechanical Adjunct to Improve the Installation of Child Restraint Systems to Vehicles

Objectives: We explored if an alternative CRS design that utilized a mechanical adjunct to amplify the force applied to the adult seat belt (intervention CRS) results in more accurate and secure attachment between the CRS and the vehicle compared to similar CRS models that use LATCH or the existing adult seat belt. We conducted three separate studies to address this question and additionally explored: (1) the contribution of prior CRS installation experience (Study 1), (2) the value-added of CRS labeling (Study 2), and (3) paper-based vs. video instructions (Study 3).

Methods: In Studies 1 and 2 we assessed a forward facing combination CRS design (intervention CRS) compared to a commercially available LATCH equipped model (control CRS) and in Study 3 we conducted a similar study using a convertible model of both the intervention and control CRS. Participants installed both CRS in a contemporary minivan and could choose which type of attachment to use for the control CRS (LATCH or seat belt); order of installation was counter-balanced. Evaluators systematically examined installations for accuracy and security.

Results: Study 1: A greater proportion of participants in both the experienced and inexperienced groups was able to securely install the intervention CRS compared to the control CRS: (45% vs. 16%, p =.0001 for experienced) and (37% vs. 6%, p =.003 for inexperienced). No differences between the CRS were observed for accuracy of installation in either user group. Study 2: A greater proportion of participants were able to securely install the enhanced intervention CRS compared to the control CRS: (62% vs. 9%, p =.001). The intervention CRS demonstrated reduced installation accuracy: (30% vs. 61%, p =.001). Study 3: A greater proportion of participants was able to securely install the intervention CRS compared to the control CRS: 79% vs. 66% p =.03, but this effect was smaller than in the previous studies. Participants were less likely to achieve an accurate installation with the intervention CRS compared to the control CRS: 54% vs. 79%, p =.004. Common accuracy errors in each study included twisting or misrouting the seatbelt when installing the intervention CRS.

Conclusions: Our results suggest that novel CRS designs that utilize mechanical advantage to facilitate attachment of the CRS to the vehicle result in a tighter installation compared to LATCH equipped models, but an increase in accuracy errors occurred.     

基于证据推理客运索道安全性评估

在比较分析现有各种评估方法的基础上,提出基于证据推理的安全性评估方法。在评估过程中,首先确定评价因素集及相应的权重和评价等级及评价等级效用值,然后利用解析算法进行证据的合成,并根据方案最终效用值到各评语等级效用值之间距离的大小确定评价等级。最后,将该方法运用于某客运索道安全评估,得出客运索道安全性评价为较好,并通过与模糊综合评价方法相比,进一步论证了该方法的可行性和有效性。     

Investigating traffic fatality trends and restraint use among rear-seat passengers in the United States, 2000–2016

Introduction: Motor-vehicle crash is one of the leading causes of unintentional injury death in the United States. Previous studies focused on fatalities among drivers and front-seat passengers, with a limited number of studies examining rear-seat passenger fatalities. The objectives of this study were to assess trends in rear-seat passenger motor-vehicle fatalities in the United States from 2000 to 2016 and to identify demographic factors associated with being unrestrained among fatally injured rear-seat passengers. Methods: Rear-seat passenger fatality data were obtained from the Fatality Analysis Reporting System (FARS) database. The fatality rate ratios for overall rear-seat passengers and for different age and sex groups were determined by comparing fatality rates in 2000 and 2016 using random effects models. Risk ratios of being unrestrained for age and sex groups were obtained using general estimating equations. Results: Compared to 2000, the overall rear-seat passenger fatality rate in 2016 decreased by 44% (95% confidence interval [CI]: 39–49%). In particular, the fatality rate among rear-seat passengers decreased more in males than females, and passengers aged 14–19 years experienced a larger decline than all other age groups. Fatally injured male rear-seat passengers had a higher risk of being unrestrained (adjusted risk ratio: 1.06, 95% CI: 1.04–1.07) than their female counterparts, and both youngest (≤13 years) and oldest (65–85 years) passengers were less likely to be unrestrained than those aged 20–64 years. Conclusions: Overall, fatality rates among rear-seat passengers have declined, with differential degrees of improvement by age and sex. Practical Applications: Continued restraint use enforcement campaigns targeted at teenagers and males would further preserve them from fatal injuries and improve traffic safety for the overall population.     

Ticketing aggressive cars and trucks (TACT): How does it work on city streets?

Objective: The purpose of this study was to determine the feasibility of modifying the Ticking Aggressive Cars and Trucks (TACT) program, originally designed to work on state highways, within a metropolitan area to reduce unsafe interactions and their related crashes between drivers of large trucks and passenger vehicles.

Methods: Using crash data, the driving behaviors most commonly associated with large truck and passenger vehicle crashes were identified. A public awareness campaign using media messaging and increased law enforcement was created targeting these associated behaviors. The frequency of these behaviors both before and after the public awareness campaign was determined through observation of traffic at 3 specific locations within the city. Each location had a sufficient volume of large truck and passenger traffic to observe frequent interactions. Pre- and postintervention data were compared using negative binomial regression with generalized estimating equations to evaluate whether the campaign was associated with a reduction in the identified driving behaviors.

Results: A comparison between crash data from before, during, and after the campaign and crashes during the same time periods in previous years did not show a significant difference (P =.081). The number of large trucks observed in traffic remained the same during pre- and postintervention periods (P =.625). The rates of negative interactions per 100 large trucks decreased for both large trucks and passenger vehicles after the intervention, with calculated rate ratios of 0.58 (95% confidence interval [CI], 0.48, 0.70) and 0.31 (95% CI, 0.20, 0.47). The greatest reduction was seen in passenger vehicles following too close, with a rate ratio of 0.21 (95% CI, 0.15, 0.30).

Conclusions: Although designed for reducing crashes on highways, the TACT program can be an effective approach for improving driver behaviors on city streets.     

突发性客流地铁站点的疏散设计优化研究

为提升突发性客流地铁站点疏散效率,以武汉市某地铁站为研究对象,采用数值模拟方法,分析不同期间节点下的疏散状况,选择最不利的典型工况(节假日A3)进行特征分析。研究结果表明：站台层拥堵时间大于站厅层拥堵时间,站台层疏散口为疏散瓶颈区;对站台层疏散口的位置与朝向进行调整,优化后疏散效率提高9.3%;验证合理增加高选择度站厅层出入口宽度等优化措施效果,发现以上策略具有一定可操作性和推广性,研究结果可为定量评估地铁站疏散能力提供参考。     

基于车站设施服务水平累积时间的地铁换乘车站风险分析

为研究地铁换乘车站风险,制定客流组织方案,基于Fruin设施服务水平划分标准,提出通过比较各级服务水平累积时间,对地铁换乘车站风险进行分析。以北京地铁1,5号线换乘站-东单站为研究对象,对单向换乘及双向换乘2种方案下,早高峰1 h的客流疏运过程进行模拟。研究结果表明：采用双向换乘方案时,客流平均密度高峰值对应区域发生变化,站台北端上行扶梯入口的E,F服务水平累积时间共增加68.5倍,站厅北端楼扶梯附近E,F服务水平累积时间共增加4.9倍,成为新的客流风险点,早高峰期间在该区域应加强客流疏导。     

山西省道路旅客运输企业安全评价指标体系研究

为了帮助山西省道路旅客运输业从源头上预防和减少交通事故,在对山西省道路旅客运输企业实地调研后,分析总结出其当前在安全生产管理体制、人员素质、运输市场等方面存在的问题,根据安全评价指标体系的构建原则和专家调研法建立了包含内部综合管理、驾乘人员管理、车辆管理和事故统计处理四大块36个指标的安全评价指标体系,并采用无需一致性检验的G1法计算指标权重。该指标体系为山西省道路旅客运输企业安全生产管理提供理论指导和实际应用价值。