Effectiveness of UK motorway services areas in reducing sleep-related and other collisions

In the UK, motorway service areas (MSAs) are believed to be helpful in reducing sleep (‘fatigue’) related collisions (SRCs), however, their actual effectiveness has yet to be evaluated. During a 2-3-year period, and over two sections of UK motorways comprising 14 MSA sites, assessments were undertaken of all fatal and injury road traffic collisions (RTCs), especially SRCs. Analyses examined whether there was: (i) a reduction in collisions 16 km beyond MSAs compared with the same distance beforehand; (ii) accumulation of collisions with increasing inter-MSA distances. Within the 16 km regions there was a non-significant fall in all RTCs from 355 before MSAs, to 304 afterwards. However, the 22% decrease in SRCs (108 vs. 84) was significant. Cars comprised the greatest reduction in SRCs possibly attributable to a MSA. Including and beyond these 16 km regions, there was no correlation between inter-MSA distances and accumulated RTCs or SRCs (n = 682 of which 181 were SRCs [26%]). There were obvious differences between MSAs in all these respects. Of the 23 fatal RTCs, 17 were SRCs. Whilst SRCs had their greatest daily incidence between 02:00 h and 06:00 h, as expected, MSAs seemed to have their least beneficial effect on SRCs during this vulnerable period, which is a matter for concern.     

合肥地铁深基坑开挖对邻近高速公路沉降的影响

针对合肥地铁深基坑开挖对邻近高速公路沉降的影响,采用MidasGTS有限元数值计算软件进行分析,建立了考虑高速公路及基坑施工过程的三维有限元模型,研究了邻近高速公路在不同开挖阶段的最大沉降变化以及不同开挖阶段高速公路的路面沉降分布规律,研究表明:路面最大沉降位置始终在离基坑最近的一侧路面,最终沉降量为7.77mm,对路面安全没有造成影响;随着开挖的进行,沉降量和沉降影响范围不断增加,但增加速率越来越缓慢;研究所得到结论可用来指导未来的相似工程。     

面向未来的电信骨干网络架构研究

通信业务的快速高质量发展对骨干传输网络带宽、时延和可靠性提出更高的要求。本文分析了运营商当前骨干传输网络现状以及存在的问题,提出了骨干核心和骨干接入两级网络架构,可将时延降低30%-60%、故障率降低90%以上、设备投资降低45%以上。     

Expression of the heat shock protein Hsp70 in chloride target cells of mayfly larvae from motorway retention pond: a biomarker of osmotic shock

The aim of this work was to study, by an in toto immunohistochemical technique, the expression pattern of the heat shock protein, Hsp70, in the widely used bioindicator species Cloeon dipterum (Linnaeus 1761) (Ephemeroptera, Baetidae), living in a motorway retention pond. All sampling and measurements have been performed from March 2002 to March 2003. The water physicochemical analyses have revealed a large increase in Na(+) and Cl(-) concentrations after the de-icing road surface in winter related to motorway maintenance that correspond to an osmotic shock (from 3.1 to 105.7 mg L(-1) for Na(+) and from 3.5 to 193.9 mg L(-1) for Cl(-)). An expression of Hsp70 was observed in the chloride cells only during the osmotic shock. In contrast, the gill insertions were Hsp70 immunoreactive in specimens collected all along the year. For comparison, the expression of Hsp70 was investigated in specimens collected in a temporary pond. C. dipterum larvae living in this pond, not submitted to such osmotic shock, do not express Hsp70 neither in chloride cells nor in gill insertions. Likewise, the expression of Hsp70 was not detected in these structures during the drying period when the abiotic conditions become progressively stressful (elevation of temperature and anoxia). As chloride cells play a key role in osmoregulation, their functional integrity is crucial for the survival of the mayfly larvae in occasionally salty freshwaters. According to the well known protective role of the Hsp70 stress proteins, it is likely that the induction of Hsp70 may protect the chloride cells from osmotic shock injuries resulting from the increase in salinity. So, the Hsp70 induction in chloride cells is designed as a useful biomarker of osmotic shock. The in toto immunohistochemical detection of Hsp70 allows to characterize both the exposure situation and biological effects in target cells induced by stresses. This method could be used as a complementary qualitative approach in the biomarker actual concept. Finally, this investigation that combines this osmotic shock biomarker and this kind of bioindicator species would be a helpful tool for the monitoring of freshwater ecological systems.     

The Effects of Motorway Runoff on Watercourses in South-West Scotland

The paper examines the potential pollution of rivers due to surface-water discharges from newly-built sections of the A74(M) motorway in south-west Scotland. A method for assessing the theoretical risks of pollution of road drainage is compared with the results of discharge monitoring. The impact of motorway runoff on the invertebrate fauna of watercourses is also investigated.     

Wertheim's hypothesis on 'highway hypnosis': empirical evidence from a study on motorway and conventional road driving

This paper aims to study the phenomenon known as ‘highway hypnosis’ or ‘driving without attention mode’, which has been defined as a state showing sleepiness signs and attention slip resulting from driving a motor vehicle for a long period in a highly predictable environment with low event occurrence, this being the case with motorways and very familiar roads [Highway hypnosis: a theoretical analysis. In: Gale, A.G., Brown, I.D., Haslegrave, C.M., Moorhead, I., Taylor, S. (Eds.), Vision in Vehicles-III. Elsevier, North-Holland, pp. 467–472]. According to Wertheim’s hypothesis on ‘highway hypnosis’, long-term driving on motorways and conventional roads, e.g. main roads, secondary roads—implies differences in the predictability of the movement pattern of the visual stimulation, in the eye musculature activity and in the type of feedback used in visual information processing (mostly extra-retinal on motorways and retinal and extra-retinal on conventional roads). All this ultimately leads to alertness differences between both road types. Our research is intended to provide empirical evidence from the hypothesis, based on the data recorded during the actual driving experience of a group of subjects on a motorway and a conventional road. We studied whether or not significant alertness differences were found-measured by EEG data relative to time periods of on-target eye-tracking performance—between motorway and conventional road driving. Our results partially support the hypothesis, as drowsiness proved to be higher on motorways than on conventional roads during the final driving period but not during the starting stage, when the opposite trend was noticed. This result could be explained by the fact that during the first driving periods the effects of the stimulus movement predictability had not yet become apparent, since they tend to show after a long drive.     

Automated section speed control on motorways: An evaluation of the effect on driving speed

Automated section speed control is a fairly new traffic safety measure that is increasingly applied to enforce speed limits. The advantage of this enforcement system is the registration of the average speed at an entire section, which would lead to high speed limit compliances and subsequently to a reduction in the vehicle speed variability, increased headway, more homogenised traffic flow and increased traffic capacity. However, the number of studies that analysed these effects are limited. The present study evaluates the speed effect of two section speed control systems in Flanders, Belgium. Both sections are located in the opposite direction of a three-lane motorway with a posted speed limit of 120 km/h. Speed data were collected at different points: from 6 km before the entrance of the section to 6 km downstream from the section. The effect was analysed through a before- and after comparison of travel speeds. General time trends and fluctuations were controlled through the analysis of speeds at comparison locations. On the enforced sections considerable decreases were found of about 5.84 km/h in the average speed, 74% in the odds of drivers exceeding the speed limit and 86% in the odds of drivers exceeding the speed limit by more than 10%. At the locations up- and downstream from the section also favourable effects were found for the three outcomes. Furthermore a decrease in the speed variability could be observed at all these data points.     

特大型互通式立交桥施工测量

本文结合郑州柳林立交桥，探讨了特大型互通式立交桥施工测量的方法及精度，其中包括施工控制测量、三维空间位置模型的建立和匝道放样。     

Behavioural effects of fixed speed cameras on motorways: Overall improved speed compliance or kangaroo jumps?

The present study evaluates the speed effects of fixed speed cameras on motorways. Two locations with speed cameras were extensively examined in a quasi-experiment: (1) a two-lane motorway and (2) a three-lane motorway, each with a posted speed limit of 120 km/h and sited in Flanders, Belgium. The effect is analysed through a before-and-after comparison of travel speeds. General time trends and fluctuations were controlled through the analysis of the speeds at comparison locations. At each of the two roads, data were gathered at five measurement points from 3 km upstream to 3.8 km downstream of the camera. Three outcomes were analysed: (1) average speed, (2) the odds of drivers exceeding the speed limit and (3) the odds of drivers exceeding the speed limit by more than 10%. Speeds decreased on average by 6.4 km/h at the camera locations. Both the odds of drivers exceeding the speed limit (−80%) and the odds of drivers exceeding the speed limit by more than 10% (−86%) decreased considerably. However, before and beyond the cameras the speeds hardly, if at all, reduced. Moreover, the analyses of the speed profiles before and beyond the cameras show that drivers do slow down quite abruptly before the camera and speed up again after passing the camera. It is concluded that a V-profile is found in the spatial speed distribution for both locations.