GEOMETRIC AND ENVIRONMENTAL CONSIDERATIONS IN HIGHWAY ALIGNMENT OPTIMIZATION

The highway alignment optimization problem is modeled to identify the preferred alignment alternatives which minimize total cost and satisfy the highway design standards. Several mathematical models have been developed during the past decades, among which the Highway Alignment Optimization (HAO) model has been used in several practical highway design projects with satisfactory results. However, several major cost components, such as vehicle operating cost and environmental cost are estimated roughly, and should be improved to yield more precise cost estimates and to allow optimization of lane widths. These are the HAO model features which this thesis seeks to improve. Lane width is an important factor in highway design, which is related to the travel speed, safety, as well as earthwork cost. This thesis employs Newton's method and Finite Difference method to search for the appropriate lane width. The preferred lane width found in the case study is 10.6 feet, for which the total cost is $233 million, and 12.5% less than the total cost at 12 feet lane width. In addition, this thesis improves the vehicle operating cost prediction by calculating the vehicle resistance force and horsepower, and estimating the fuel consumption based on the fuel consumption rate (g/hp-hr). Moreover, the environmental cost, particularly the vehicle emissions cost is incorporated in the newly improved HAO model. It is found that the vehicle emission cost decreases by 9% after including the environmental cost component in the model objective function. The results of the case study and sensitivity analyses indicate that the improved HAO model can find good highway alignments efficiently in tough topographic environmental. Moreover, the model can jointly consider the social, economic and environmental consequences, and result in less fuel consumption and pollutant emissions

Experimental study of carriageway operational condition influence on acoustic roadside area pollution

Environmental noise management is an important part of the policy across the EU policy context, because transportation noise is a significant local environmental problem for most of the urban population. Increasing numbers of vehicles are associated with growing noise levels from road transport in urban areas and rising public health problems. Motor transport is considered to be a main source of noise pollution, so it is important to investigate the level of traffic noise and assess the relationship with traffic flows. The paper describes the main methods for determination of noise characteristics of traffic flows. The dependences for the prediction of the equivalent noise level and the results of field measurements of sound levels are presented. The results of field experiments and the calculated values of sound levels obtained by the analytical method are tested for homogeneity, using the Wilcoxon test. Experimental studies have established that the external sound level depends largely on the speed of vehicles, road conditions, and basic operating characteristics of highways. The analytical method associated with the use of deterministic and probabilistic models makes it possible to predict the traffic noise. But when dealing with the foregoing methods, there arise specific problems, many of which have not been resolved: there is no uniform terminology, nor is there any consensus on the use of noise characteristics of traffic flows in calculations at different stages of construction and reconstruction of highways of a certain traffic flow model under conditions of human settlements. Standardized measurement methods have been established and revised throughout the years by many renowned researchers. These methodologies have been revised in order to minimize problems that may occur and may not be foreseen by a less experienced researcher when adopting the measurement methods. Standardizing the measurement method is also useful for researchers because it becomes possible for researchers from around the world to compare their data. The joint effect of road conditions and the operational status of the roadway on the acoustic pollution of the roadside area is not fully taken into account. Therefore, applying the internationally recognized acoustical measurement standards is a good way to start any noise measurement experiment. The purpose of experimental research is to investigate the joint effect of road conditions and the operational status of the roadway on the acoustic pollution of the roadside area of settlements: identify the main characteristics of noise produced by traffic flows, consider the comparability of results of the field experiment and analytical computations. Slopes of 20…40‰ have little impact on the noise caused by the movement of passenger cars and trucks. In this case, the average acoustic emissions are identical to those used in the prediction of noise mode

An evaluation of the sustainability of the tramline in Croydon.

This thesis is a descriptive analysis of the sustainability of the Croydon Tramlink, using indicators as the bases of the examination. A sustainable transport system is vital for the wellbeing of society. However the present British system, with the emphasis on road building rather than improving the dilapidated public transport network, is experiencing problems on an enormous scale. Current Government policy such as Transport 2010 has been heavily criticised and is in urgent need of review. The rise of the concept of sustainability has increased awareness of transport problems and of the disastrous consequences if predicted trends of growth in cars materialise. Whilst the concept of sustainability has generally been accepted in modern society, debate continues about the implications of sustainable transport, and how best to improve the situation. The main objective of the report is to evaluate the sustainability of the Croydon Tramlink within environmental, social and economic sub-contexts. Indicators for each of the sub-contexts shall be drawn from the literature review in preparation for the analysis. Case studies of European tram networks are also introduced to allow for any comparison between the performances of systems. The research paradigm is of a positivist nature and this is reflected in the choice of a survey to collect primary data that is allocated into categories under a quantitative approach. Secondary data is also presented to add weight to the arguments. The analysis argues that the Croydon Tramlink is a highly sustainable mode of transport and one key inference is that more networks should be considered across the country. Other conclusions include changes in policy reform and social values as attempts to highlight the benefits of sustainability to both natural and human environments

Land use planning for utilizing biomass residues in Tuscia Romana (central Italy) : preliminary results of a multi criteria analysis to create an agro-energy district

This study provides a preliminary agro-environmental, economic and energetic analysis to critically evaluate the biomass potential of an area of central Italy (Tuscia Romana). This area is selected as representative for agro-forestry from its orographic characteristics, climatic conditions, land use and potential energy sources. Accordingly, the model we have obtained could be used for other similar areas of central Italy. We have assessed the potential agro-forestry biomass availability, energy po-tential and transport infrastructure using multi criteria analysis and geographic information system approaches. Finally, optimum locations to develop an energy plant were identified. This model could be applied at a local level to help deliver environmental policy

Vehicle and Traffic Safety

The book is devoted to contemporary issues regarding the safety of motor vehicles and road traffic. It presents the achievements of scientists, specialists, and industry representatives in the following selected areas of road transport safety and automotive engineering: active and passive vehicle safety, vehicle dynamics and stability, testing of vehicles (and their assemblies), including electric cars as well as autonomous vehicles. Selected issues from the area of accident analysis and reconstruction are discussed. The impact on road safety of aspects such as traffic control systems, road infrastructure, and human factors is also considered

Divisive connections: Theory and tools for the quantification of barrier effects in transport infrastructure projects

Transport infrastructure increases regional accessibility but at the same time it creates barriers that reduce local accessibility. These barriers reduce social contacts between people, and limit access to services and leisure. Barriers make cycling and walking less attractive, which has negative impacts on health, and can lead to increased emissions from cars. Assessments of barrier effects are commonly based on general descriptions and rough estimations, although methods for the quantification of these effects have been developed. Reasons for not using these methods are: limited dissemination, difficulty in separating barrier effects from other effects, and differences in the terminology that is used to describe them. This thesis aims to make existing academic knowledge and tools regarding the quantification of barrier effects more applicable in practice. The thesis presents a conceptual model that defines five determinants of barrier effects: Transport features, Crossing facilities and street network, People’s abilities, Land use, and People’s needs, and defines three levels of barrier effects. Further, the thesis lists indicators and methods for quantifying barrier effects. The model and indicators are studied in two case studies. In the first, four of the indicators were operationalised in a transport infrastructure project using conventional GIS tools. In the second, the indicators were studied in an ongoing transport infrastructure project using an action research approach. In this study, participants reported how the barrier effects analyses contributed to the impact assessments with transparent and precise support, which allowed the stakeholders to solve a long-standing conflict about the localisation of the infrastructure. One of the central issues that was revealed is the need for collaboration in order to create input material for the analyses. Based on these results, the main finding of this thesis is that knowledge of both social and technical processes in the assessment of barrier effects is required for making existing academic knowledge and instruments more applicable in practice

Normalizing accidents: cars, carnage and the disappearance of social problems

Thesis (Ph.D.)--Boston UniversityThis dissertation probes critical questions about the relationship between the production of cultural meanings, social power, and material objects. By using the public discourse on traffic accidents in the United States as a historical case study, this study investigates in particular the various ways by which social groups respond to unintended technological consequences and dangers within definitional processes of collectively constructing a social problem. The textual-thematic analysis draws largely upon theories from social problems literature and science & technology studies, as it looks at a number of salient historical claimsmakers, sites of discourse production, and cultural vehicles of meaning making. Specifically, the contributions of the private insurance industry, safety establishment, consumer market, automobile clubs, and printed media are closely dissected to flesh out the contours and content of the accident problem's construction and development through time. In line with a contextual constructivist approach to social problems analysis, the research has observed the emergence, evolution, and eventual waning of the accident issue along several structural anchors that provide possible explanations for some of these dynamics. To a great extent, the traffic accident problem has gradually 'disappeared' in America throughout the twentieth century - a disappearance that is not physical but conceptual. Specifically, it means that the troubling social condition is defined as something to live with, a necessary evil of which there seems to be limited ability or desire to substantially affect or eradicate. The sociological concept I employ to name this particular trajectory towards problem attenuation is normalization. Applied to the case analyzed here, the findings offer a way to understand the processes by which traffic accidents become nom1alized in America as an acquiescent price to pay for the benefits of the automobile. Theoretically, these conclusions have laid the groundwork for producing a hypothetical model of social problems normalization. The model highlights the role played by several cultural devices of claimsmaking in affecting issue attenuation or 'disappearance.' When the problem is constructed through highly technicizing, commensurating, commodifying, and socially controlling modalities of sense making, the likelihood of its normalization and eventual floundering increases