996 resultados para Contaminant transport


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Intelligent Transport Systems (ITS) have the potential to substantially reduce the number of crashes caused by human errors at railway levels crossings. Such systems, however, will only exert an influence on driving behaviour if they are accepted by the driver. This study aimed at assessing driver acceptance of different ITS interventions designed to enhance driver behaviour at railway crossings. Fifty eight participants, divided into three groups, took part in a driving simulator study in which three ITS devices were tested: an in-vehicle visual ITS, an in-vehicle audio ITS, and an on-road valet system. Driver acceptance of each ITS intervention was assessed in a questionnaire guided by the Technology Acceptance Model and the Theory of Planned Behaviour. Overall, results indicated that the strongest intentions to use the ITS devices belonged to participants exposed to the road-based valet system at passive crossings. The utility of both models in explaining drivers’ intention to use the systems is discussed, with results showing greater support for the Theory of Planned Behaviour. Directions for future studies, along with strategies that target attitudes and subjective norms to increase drivers’ behavioural intentions, are also discussed.

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In this thesis a new approach for solving a certain class of anomalous diffusion equations was developed. The theory and algorithms arising from this work will pave the way for more efficient and more accurate solutions of these equations, with applications to science, health and industry. The method of finite volumes was applied to discretise the spatial derivatives, and this was shown to outperform existing methods in several key respects. The stability and convergence of the new method were rigorously established.

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Carbon dioxide (CO2) is considered the most harmful of the greenhouse gases. Despite policy efforts, transport is the only sector experiencing an increase in the level of CO2 emissions and thereby possesses a major threat to sustainable development. In contrast, a reduced level of mobility has been associated with an increasing risk of being socially excluded. However, despite being the two key elements in transport policy, little effort has so far been made to investigate the links between CO2 emissions and social exclusion. This research contributes to this gap by analysing data from 157 weekly activity-travel diaries collected in rural Northern Ireland. CO2 emission levels were calculated using average speed models for different modes of transport. Regression analyses were then conducted to identify the socio-spatial patterns associated with these CO2 emissions, mode choice behaviour, and patterns of participation in activities. This research found that despite emitting a higher level of carbon dioxide, groups in rural areas possess the risk of being socially excluded due to their higher levels of mobility.

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Heavy metals that are built-up on urban impervious surfaces such as roads are transported to urban water resources through stormwater runoff. Therefore, it is essential to understand the predominant pathways of heavy metals to the build-up on roads in order to develop suitable pollution mitigation strategies to protect the receiving water environment. The study presented in this paper investigated the sources and transport pathways of manganese, lead, copper, zinc and chromium, which are heavy metals commonly present in urban road build-up. It was found that manganese and lead are contributed to road build-up primarily by direct deposition due to the re-suspension of roadside soil by wind turbulence, while traffic is the predominant source of copper, zinc and chromium to the atmosphere and road build-up. Atmospheric deposition is also the major transport pathway for copper and zinc, and for chromium, direct deposition by traffic sources is the predominant pathway.

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This paper investigated the influence of nano-silica (NS) on the mechanical and transport properties of lightweight concrete (LWC). The resistance of LWC to water and chloride ions penetration was enhanced despite strength marginally increased. Water penetration depth, moisture sorptivity, chloride migration and diffusion coefficient was reduced by 23% and 49%, 23% and 10%, 5% and 0%, 22% and 12% compared to the two reference LWC mixes (pure cement and 60% slag blended cement), respectively with 1% NS. Such improvements were attributed to more compact microstructures because the micropore system was refined and the interface between aggregates and paste was enhanced.

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The Queensland Department of Transport and Main Roads (TMR) required an evaluation framework for the Queensland Alcohol Ignition Interlock Program (AIIP). The objective of this project was to develop a framework to evaluate the AIIP in terms of its effect on road safety outcomes.

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Unlicensed driving remains a serious problem for road safety, despite ongoing improvements in traffic law enforcement practices and technology. While it does not play a direct causative role in road crashes, unlicensed driving undermines the integrity of the driver licensing system and is associated with a range of high-risk behaviours. This report examines official road crash data from Queensland for the years 2003-08 to compare the crash involvement patterns of unlicensed drivers with those of licensed drivers and explore the scope and nature of unlicensed driving. This study replicates and extends upon two previous studies examining the involvement of unlicensed drivers in crashes in Queensland (Watson, 2004a; 2004b; Watson & Steinhardt, 2006).

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A state-wide observational study was undertaken by the Centre for Accident Research and Road Safety – Queensland (CARRS-Q) in order to investigate the prevalence of unregistered vehicles on Queensland roads. This study was conducted on behalf of the Queensland department of Transport and Main Roads (TMR). This study builds upon research commissioned by Queensland Transport and conducted in 2000, 2003 and 2005. Vehicles were observed throughout Queensland from April 13th, 2010 to May 8th, 2010 in a mix of small rural towns, regional centres and metropolitan locations. The locations sampled for this study were restricted to destinations (e.g. shopping centres, hospitals, airports and park-and-ride facilities) rather than residential areas, and a variety of different destinations were sampled. Sampling vehicles in these types of locations provides a higher probability that the vehicles captured in the survey are being driven on a regular basis (Younglove, et al. 2004).

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Vehicle registration represents an important component of the management of the road transport system in Queensland, with most vehicles required to be registered before they can be driven or parked on a public road (Department of Transport and Main Roads, 2010b). In addition to the collection of taxes for road construction and maintenance, the current registration system also: • Sets the safety standards required for vehicles to be allowed on public roads; • Allows driver behaviour to be managed by identifying vehicles, and the responsible owners of vehicles, for enforcement purposes; and • Facilitates the collection of insurance premiums for the Queensland Compulsory Third Party (CTP) insurance scheme.

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Unlicensed driving is a serious problem in many countries, despite ongoing improvements in traffic law enforcement practices and technology. The term ‘unlicensed driver' is generally used to refer to people who operate a motor vehicle or motorcycle without a valid driver's licence, including those who: • have let their licence expire; • have been disqualified or suspended from driving; • hold an inappropriate class of licence for the vehicle they drive; • drive outside the restrictions of a special licence; • don’t currently hold a licence; or • have never held a licence.

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This report documents a second, revised roadside licence check survey undertaken by the Queensland Police Service (QPS) in conjunction with roadside random breath testing (RBT) traffic operations. The methodology utilised was devised by the Centre for Accident Research and Road Safety – Queensland (CARRS-Q), Transport and Main Roads (TMR) and QPS, after consideration of a number of options.

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Unlicensed driving is a serious problem in many countries, despite ongoing improvements in traffic law enforcement practices and technology. Unlike alcohol impairment and speeding, unlicensed driving does not play a direct causative role in road crashes. However it represents a major problem for road safety in two respects. Firstly, it undermines the effectiveness of driver licensing systems by preventing the allocation of demerit points and reducing the impact of licence loss (Watson, 2004b). Secondly, there is a growing body of evidence linking unlicensed driving to a cluster of high-risk behaviours including drink driving, speeding, failure to wear seat belts and motorcycle use (Griffin & DeLaZerda, 2000; Harrison, 1997; Watson, 1997, 2004b). Consistent with this, utilising the quasi-induced exposure method, Watson (2004a) estimated that in Queensland, unlicensed drivers were almost three times more likely to be involved in a reported crash than licensed drivers.