Search results for " transportation"
showing 10 items of 511 documents
From cars to bikes – the feasibility and effect of using e-bikes, longtail bikes and traditional bikes for transportation among parents of children a…
2017
Abstract Background The present study aims to increase bicycling and level of physical activity (PA), and thereby promote health in parents of toddlers, by giving access to different bicycle types. There is a need for greater understanding of e-bikes and their role in the transportation network, and further effects on PA levels and health. Moreover, longtail bikes could meet certain practical needs not fulfilled by e-bikes or traditional bikes, hence increased knowledge regarding their feasibility should be obtained. No previous studies have investigated whether providing an e-bike or a longtail bike over an extended period in a sample of parents of toddlers influence objectively assessed a…
Rail freight transport and demand requirements : an analysis of attribute cut-offs through a stated preference experiment
2014
This paper analyses the choice between road and rail in Spain where rail market share for freight is still residual. Discrete choice models are estimated with data obtained through a two-phase fieldwork, thus allowing us to carry out a stated preference efficient design for each interviewee. We analyse the existence of attribute cut-offs and the presence of a segment of the population with a zero value of frequency. Our results show that ignoring the existence of cut-offs and segments of the population with polarised valuations can lead to erroneous conclusions in terms of the possibilities of rail for absorbing significant quota.
Geovisualizing the sail-to-steam transition through vessel movement data
2017
International audience; Technological transitions in the maritime and port industries go along with increased transport and economic efficiency, resulting in faster movements and longer travelled distances. Yet, such transformations may also enhance disparities between winners and loosers, should they be ports or shipping companies. This research focuses on the particular case of the transition from sail to steam over the period 1890-1925, which witnesses the rapid replacement of sailing vessels, the latter concentrating 65% of the world fleet in 1890 but only 3.5% in 1925. It applies a variety of measures to compare how these two layers overlap in the network (at links and ports) and what …
Smart cities approach for Colombian Context. Learning from ITS experiences and linking with government organization
2015
The forecast (world bank) related to the growth of world population tends to be around 9000 million to 2050 and most of the people will live in the cities or in conurbations, this means that, a new approach for support the development of the cities needs to be analyzed. Currently, the mankind has developed and produce a lot of technology advances and many of them are related to the Information and communications technology (ICT). In this way, ICT has become in a key element for the development of the cities, even, introduce the ICT concept in the context of the cities has provoked a new scope for the cities that is called Smart City or Digital City. In this paper, it is presented an approac…
Urban segregation and unemployment: A case study of the urban area of Marseille – Aix-en-Provence (France)
2018
International audience; In this paper, we study the effects of the spatial organization of the urban area of Marseille – Aix-en-Provence on unemployment there. More specifically, differences in the characteristics of the residential population induce urban stratification with the result that urban structure may affect the probability of employment. In order to evaluate the effects of spatial structure on unemployment, we implement a spatial probit model to reveal the employment probabilities of young adults still living with their parents. Our results support the hypothesis that living in or near a deprived neighborhood decreases the probability of employment.
More firms, more competition? The case of the fourth operator in France's mobile phone market
2010
Accepted, Forthcoming; International audience; To foster competition the French government authorized a fourth operator, ‘Free', to enter the country's mobile phone market at the end of 2009 alongside Orange, SFR and Bouygues Telecom (BT), who held respectively one-half, one-third and one-sixth of the market. By using a stylized model of France's phone market, we have examined what we call the regulator's nightmares and dreams. If Cournot competition is in place before Free's entry, minimizing the total profit fails to maximize the consumer surplus and the total surplus; the maximum most realistic price fall is 6.7% compared to three-way competition and could be 1.7% only; if Orange, SFR an…
Automatic Segmentation and Enhancement of Pavement Cracks Based on 3D Pavement Images
2019
Pavement cracking is a significant symptom of pavement deterioration and deficiency. Conventional manual inspections of road condition are gradually replaced by novel automated inspection systems. As a result, a great amount of pavement surface information is digitized by these systems with a high resolution. With pavement surface data, pavement cracks can be detected using crack detection algorithms. In this paper, a fully automated algorithm for segmenting and enhancing pavement crack is proposed, which consists of four major procedures. First, a preprocessing procedure is employed to remove spurious noise and rectify the original 3D pavement data. Second, crack saliency maps are segmente…
Deviations in pedestrian itineraries in urban areas: a method to assess the role of environmental factors
2010
Walking has long been neglected in urban-mobility research, but it is now making its way into numerous studies using various approaches. Empirical data are often processed in well-known models of flow allocation to study the behaviour of pedestrians and to identify their preferences. However, these models assume that route choices are predetermined at the start of each trip and do not admit any possible intervening decision along these trips. We propose to overcome this limitation through a new method for the analysis of pedestrian behaviour. This method, which we call ‘deviation analysis’ consists of (1) identifying the intersections from which a pedestrian has chosen a route longer than …
Energy-environmental and cost assessment of a set of strategies for retrofitting a public building toward nearly zero-energy building target
2017
Abstract The purpose of this study was to assess an energy retrofit of a building representative of those in public tertiary stock, to improve energy performance toward nearly Zero-Energy Building (nZEB) requirements. The building is located in the campus of the Politecnico di Milano University (Italy). Several hypothetical improvements regarding the building envelope and plants were assessed in terms of energy savings, costs, and the reduction of greenhouse gas emissions. The results of the study show that it is possible to reduce primary energy demand and associated emissions up to 40% from the current values by adopting market-available and well-proven technological solutions for retrofi…
Capacity and safety analysis of hard-shoulder running (HSR). A motorway case study
2016
Abstract Operational motorway conditions can be improved by introducing traffic flow management and control systems, such as ramp metering (RM), high occupancy vehicle (HOV) lanes, real-time variable speed limits (VSLs), reversible lanes (RL), automated highway systems (AHS) and hard-shoulder running (HSR). The effects of such devices need to be examined in terms of capacity and safety. This paper examines the case study of the Italian motorway A22, which is supposed to be equipped with an HSR system implemented along 128 km in order to reduce congestion with consequent improvement in levels of service (LOS). We studied the traffic processes (capacity, flow distribution between lanes, relia…