Age related annual crash incidence rate ratios in professional drivers of heavy goods vehicles

ObjectivesEvidence concerning crash risk for older heavy vehicle drivers is sparse, making it difficult to assess if it is prudent to encourage older drivers to remain in the workforce in a climate of labour shortages. The objective of this study was to estimate annual crash rate ratios of older male heavy vehicle drivers relative to their middle aged peers.MethodsData utilized in this study includes all crashes meeting inclusion criteria involving heavy goods vehicles, categorised as rigid trucks and articulated trucks; this data was recorded by the New South Wales Roads and Traffic Authority. The exposure to the risk of a crash was represented by distance travelled for each vehicle type and year, by age of driver, as estimated by the Australian Survey of Motor Vehicle Use. Negative binomial regression modelling was applied to estimate annual crash incidence rate ratios for male drivers in various age groups.ResultsA total of 26,146 crashes occurred in New South Wales during 1999–2006, involving a total of 54,191 vehicles; removing observations that did not meet the inclusion criteria, 19,736 observations remained representing 12,501 crashes. For rigid trucks, the incidence rate ratio for drivers aged 65+ years, compared to 45–54 year olds, was 0.74 (95% CI 0.51, 0.98). For articulated trucks, the annual crash incidence rate ratio for drivers aged 65+ years compared to 45–54 year olds was 1.4 (95% CI 0.96, 1.9), and that for drivers aged 55–64 years compared to 45–54 year olds was 1.1 (95% CI 0.83, 1.3).ConclusionsOlder male professional drivers of heavy goods vehicles have lower risk of crashes in rigid vehicles, possibly due to accrued driving experience and self-selection of healthy individuals remaining in the workforce. Thus, encouraging these drivers to remain in the workforce is appropriate in the climate of labour shortages, as this study provides evidence that to do so would not endanger road safety.     

公路隧道照明LED灯具选型及布设方法初探

文章依托具体工程实例,介绍了LED灯具的基本参数,阐述了LED灯具照明的计算条件和亮度要求,并探讨了公路隧道照明LED灯具的选型、布设方法及控制要点,通过工程现场测试,证明了LED灯具选型和布设的合理性。     

龙里二号隧道中导洞溶洞坍方处治

文章介绍了阿荣旗-北海高速公路广西段六寨-河池段龙里二号隧道中导洞施工溶洞坍方的情况和综合处治技术方案,并对溶洞坍方处理过程及方法进行了详细阐述,为类似的隧道坍方溶洞处理提供参考。     

A comparative analysis of US toll policy

In the US, there is a long tradition of toll roads, beginning with the Lancaster Turnpike that was built at the end of the 18th century connecting Philadelphia and Lancaster. There are currently more than 300 toll facilities in the US, which is probably the largest number of toll facilities in the world. These facilities represent a wide range of conditions, from hypercongested facilities in large metropolitan areas such as New York City to toll highways in rural areas. The toll structures are equally diverse, ranging from multi-tier price structures with frequent user, carpool, and time of day discounts; to simpler structures in which the only differentiation is made on the basis of the number of axles per vehicle. The toll rates are typically set by the agencies that operate or own the toll facilities. The rules or formulas by which these tolls are determined are not generally available to the public, though it is safe to say that toll decisions are made taking into account technical considerations, as well as the all important criterion of political acceptability. However, data on toll rates and how they change by vehicle types and by some other attributes are readily available.The overall objective of this paper is to analyze the toll data from various facilities across the US to gain insight into the overall factors affecting the tolls. A more specific objective is to assess—though in a rather approximate fashion—if the tolls by vehicle type, relative to each other, are appropriate and consistent with economic theory. This is achieved by comparing tolls to approximate indicators of road space consumption and pavement deterioration. The literature review confirmed that this is the first time such research has been conducted which is an important first step toward an analysis of the efficiency of current toll policies.The analyses in this paper are based on a random sample of all toll facilities across the US. The toll dataset, which include toll rates for passenger cars, busses, and three different truck types, is assembled mainly from the available information on the web sites of various toll agencies. After cleaning the data, the authors used econometric modeling to estimate a set of ordinary least squares (OLS) regression models that express tolls as functions of independent variables. Three families of models were estimated: linear models, models based on expansions of Taylor series, and models based on piece-wise linear approximations to non-linear effects. The resulting models were analyzed to identify the salient features of current toll policies towards different vehicle types.     

美国交通运输机构及职能简介

从4个层次分别介绍美国联邦政府运输机构、美国联邦独立运输管理机构、美国地方交通运输机构及美国道路交通管理机构的职能分工，侧重于其在道路交通管理方面的职能。     

酸性石料工程性质的试验研究

广西高速公路沥青路面面层多采用辉绿岩材料,储量少,成本高。作者通过对花岗岩、砂岩等酸性石料的基本物理性质、工程性质等进行试验研究后显示,采取适宜的防止剥落措施,酸性石料沥青混合料完全满足抗水损害能力和抗车辙性能,可以用作高等级沥青路面表面层或磨耗层材料,从而达到就地取材、降低工程造价的目的。     

固化剂稳定粉土路面基层材料的路用性能研究

通过对两种不同固化剂在不同剂量情况下稳定粉土的强度、刚度、水稳定性、冻融稳定性及干缩、温缩等性能的实验研究,分析了水泥基及石灰基的两种固化剂在相同配合比及同一种固化剂不同配合比或不同龄期情况下的路用性能的变化规律,得出了适当配合比的固化剂稳定粉土能够满足路面基层材料的要求,并结合使用性能提出了实际应用时应重点注意的问题,为工程应用做了一定的准备。     

公路隧道交通量的预测及分析

公路隧道交通量的预测对隧道通风系统的节能以及降低隧道运营成本有很重要的意义。分别利用多元统计分析法和BP神经网络两种方法对公路隧道交通量进行了预测,并对两类预测数据进行分析比较,得出了多元统计分析法适用于车流量少而且稳定的公路隧道的预测,而BP神经网络法则适用于车流量大而且不稳定的公路隧道的预测的结论。     

底盘测功机工作原理及使用

底盘测功机以其方便、安全和溯源性好等优势在汽车开发及检测工作中得到广泛应用。利用数据采集卡实现驱动力和车速的测量,通过单片机与PC机通信可实现传感器信号的采样和数据传送。文章采用底盘测功机测量驱动轮输出功率来换算发动机功率,分析驱动轮输出功率不足的原因并得出底盘的技术状况。底盘测功机可用以模拟汽车在实际行驶时的阻力、测定汽车的使用性能、检测汽车的技术状况以及诊断汽车故障。     

Path-differentiated pricing in congestion mitigation

Instead of charging tolls on individual links, this paper considers doing the same on paths. Path and link tolls are “valid” if they encourage motorists to use routes that collectively lead to a target distribution, e.g., one that minimizes travel delay. Because the numbers of valid link and path tolls are typically infinite, an objective in pricing tolls is to find a set of valid tolls that yields the least revenue to lessen the financial burden on motorists.Path tolls are generally more flexible than link tolls and this paper shows that this flexibility can substantially reduce the financial burden on motorists. Additionally, valid path tolls yielding the least revenue possess characteristics with interesting policy implications. To determine these path tolls, it is natural to formulate the problem as a mathematical program with complementarity constraints. However, this paper also investigates alternative formulations that highlight the problem’s complexity and suggest ways to solve the problem efficiently.