Delivering improved alerts,warnings, and control assistance using basic safety messages transmitted between connected vehicles

When vehicles share their status information with other vehicles or the infrastructure, driving actions can be planned better, hazards can be identified sooner, and safer responses to hazards are possible. The Safety Pilot Model Deployment (SPMD) is underway in Ann Arbor, Michigan; the purpose is to demonstrate connected technologies in a real-world environment. The core data transmitted through Vehicle-to-Vehicle and Vehicle-to-Infrastructure (or V2V and V2I) applications are called Basic Safety Messages (BSMs), which are transmitted typically at a frequency of 10 Hz. BSMs describe a vehicle’s position (latitude, longitude, and elevation) and motion (heading, speed, and acceleration). This study proposes a data analytic methodology to extract critical information from raw BSM data available from SPMD. A total of 968,522 records of basic safety messages, gathered from 155 trips made by 49 vehicles, was analyzed. The information extracted from BSM data captured extreme driving events such as hard accelerations and braking. This information can be provided to drivers, giving them instantaneous feedback about dangers in surrounding roadway environments; it can also provide control assistance. While extracting critical information from BSMs, this study offers a fundamental understanding of instantaneous driving decisions. Longitudinal and lateral accelerations included in BSMs were specifically investigated. Varying distributions of instantaneous longitudinal and lateral accelerations are quantified. Based on the distributions, the study created a framework for generating alerts/warnings, and control assistance from extreme events, transmittable through V2V and V2I applications. Models were estimated to untangle the correlates of extreme events. The implications of the findings and applications to connected vehicles are discussed in this paper.     

Impact assessment of extreme weather events on transport networks: A data-driven approach

The present paper presents a data-driven method for assessing the resilience of the European passenger transport network during extreme weather events. The method aims to fill in the gap of current research efforts regarding the quantification of impacts attributed to climate change and the identification of substitutability opportunities between transport modes in case of extreme weather events (EWE). The proposed method consists of three steps concerning the probability estimation of an EWE occurring within a transportation network, the assessment of its impacts and the passengers’ flow shift between various transport modes. A mathematical formulation for the proposed data-driven method is provided and applied in an indicative European small-scale network, in order to assess the impacts of EWE on modal choice. Results are expressed in passenger differentiated flows and the paper concludes with future research steps and directions.     

大型活动交通影响评价方法

大型活动吸引和产生的突增交通量会造成周边地区的交通拥挤。通过比较大型活动与大型商业建设项目的交通影响评价特点和分析大型活动交通管理的影响因素,分别针对“提供一次性服务的大型活动”和“提供长效服务的大型活动”,设计了交通需求的预测方法。以交叉口服务水平分析方法为基础,提出一种了大型活动的交通影响评价方法。以长春市南岭体育场举办的“中国足球甲A联赛”为对象,运用Vissim微观交通仿真软件对所提出的方法进行了初步验证。结果表明,在大型活动条件下,所提出的方法能够确定需要进行交通管制的空间范围。     

Factors influencing travel mode choice among families with young children (aged 0–4): a review of the literature

Life events, such as the birth of a child, disrupt habitual travel behaviour and provide a valuable opportunity to influence the adoption of sustainable transport practices. However, in order for sustainable travel practices to be adopted, an understanding is required of the factors that influence travel mode choice among families with young children. Research in this field is particularly timely given many in the millennial generation, a comparably large cohort, are approaching this life stage. This comprehensive literature review develops a framework of factors influencing travel mode choice among families with young children. The findings reveal a multitude of factors influence decisions about mode choice, and, in particular, encourage travel by car, when travelling with young children. The paper concludes with an agenda for future research about travel among families with young children, a largely overlooked group of transport users.     

Disaster prevention and strategic investment for multiple ports in a region: cooperation or not

With the growth of maritime transportation, seaports have become critical to the world economy as linking nodes between shipping and inland transport. However, the port system is fragile under certain unconventional emergency events. This study addresses the issue of investment on disaster prevention within the port competition context. The present model discusses and compares four situations of different relationships and strategies of pre-disaster prevention between two adjacent ports. Results indicate that both ports increase the disaster prevention investment under the cooperation scenario compared with that in the case of non-cooperation wherein they are complementary ports. Meanwhile, a numerical simulation is conducted to examine the collective and individual rationality of both ports. Although cooperation strategy decreases the total risk cost of two ports, one of the two ports may profit, whereas the other may suffer losses.     

大型活动的交通调查及分析

随着我国经济的不断发展,全国各地举行的大型活动越来越多。大型活动产生突增交通量造成周边地区的交通拥挤,而分析大型活动带来的交通拥挤则是以对大型活动的交通调查为基础的。以长春市南岭体育场周围的道路交通系统为基础,对举行足球比赛产生的观众到达高峰和离开高峰进行了实地调查,并通过问卷的方式对观众出行方式及其他与此活动相关的特性进行了分析。     

大规模侵权责任化解机制探讨

论文从大规模侵权与大规模侵权责任化解机制的概念出发,对大规模侵权责任化解机制在解决大规模侵权损害救济的重要作用进行了学理分析,并从大规模侵权民事责任的法律化解、行政化解和社会救济化解等3个方面,围绕大规模侵权责任承担的实体保障、程序保障、清偿保障,以及政府责任担当和社会救助等方面的内容,论证了大规模侵权责任化解机制的具体内容,强调多元化、综合化的责任承担模式,对受害群体进行最大力度的救助,是解决大规模侵权纠纷的重要保证。     

温拌沥青混合料施工技术研究

文章从温拌沥青混合料的作用机理、分类及优势入手,依托某试验路铺筑实例,阐述了温拌沥青混合料的拌和、运输、摊铺和碾压工艺流程及技术要点,并对铺筑的温拌沥青路面的各项质量控制指标进行了检测分析。     

对海上突发事件及其应急机制的思考

预防和处置海上突发事件,已成为当前海警部队需要认真研究的重要课题。根据当前海上突发事件的特点,来建设和完善海上突发事件的应急机制,显得尤为迫切。根据海上突发事件所具有的发生的不确定性、种类多频率高、反应的紧迫性、处置的艰难性、一定的涉外性的特点,其应急机制应着重围绕机制的防控体系、训练体系、指挥体系、公关体系和善后体系来综合建设。     

The shoaling of nutrient-enriched subsurface waters as a mechanism to sustain primary productivity off Central Baja California during El Niño winters

Using CalCOFI data for coastal shallow stations (above 100 m depth), higher than expected nitrate concentrations were detected in near-surface high-temperature waters off of Central Baja California during some El Niño winters. Though recent data are not available for Central Baja California, past El Niño data, though limited, showed nitrate concentrations above 16 μM at temperatures above 16 °C, and nitrate concentrations between 1 and 2 μM at 19 °C, while the previously established relationship of temperature and nitrate for California Current waters predicts nitrate depletion above 14 or 15 °C. The anomalous, high temperature–high nitrate enrichment events documented in Central Baja California were detected as shallow as 9 m and as deep as 73 m, were associated with low-oxygen (between 2 and 4 ml/l) and high-salinity (between 33.8 and 34.3 psu) waters, and occurred during the winter months of an El Niño year. Using recent data for San Diego, CA, similar but weaker enrichment events were detected for the El Niño winter of 1997–1998. The periodic shoaling of a subsurface subtropical water mass of high temperature, high salinity, low oxygen and high nutrients during some El Niño winters is proposed to cause periodic enrichment and to maintain productivity during warming events in this area. Enrichment events were not detected off Ensenada, in Northern Baja California, possibly due to the amplification of the onshore flow during El Niño there, or due to the Ensenada front. The proposed mechanism of periodic enrichment of nutrient-depleted surface waters during some El Niño winters by subsurface waters from the California Undercurrent may explain the following: (1) survival of giant kelp forests at their southern limit in Central Baja California documented during past El Niño events in warm waters, (2) the rapid recovery and high carrying capacity of giant kelp documented after the mass disappearance during El Niño 1997–1998, and (3) the increase in the extent of mesotrophic chlorophyll detected in the area during the 1997–1998 and 1982–1983 El Niño events.