101 research outputs found
Monocentric analysis of restricting the budget share of housing alone or with transportation
Considering the prolonged rise of energy price and the still elevated housing prices, the policy to limit the share of housing expenses in the households' budget, so as to secure their solvability, has been criticized. Supposedly, it induces people to get farther from the city center in search for cheaper housing prices, but with subsequent increased transportation costs that are often disregarded during the house search process. Therefore, to improve the well-being of households, it has been advocated to set a constraint on the share of both housing and transportation expenditure. The paper is purported to analyze and compare the effects of the two policies in terms of: 1. Well-being of the households; 2. Land-use: city size and density curve; 3. Solvability of the households; 4. Transportation costs. The analysis is carried out within the classical monocentric model of urban economics. After setting a general analysis, an applied model is specified to capture the effects of each policy in straightforward formulae. It is shown that constraining housing expenses may increase the well-being of households. Besides, both policies prove effective in reducing urban sprawl and hereby energy consumption. Thus the choice of the optimal policy will depend on the local authority's objectives.monocentric model, urban economics, housing expenses, transportation expenses, housing policy
Monocentric analysis of restricting the budget share of housing alone or with transportation
Considering the prolonged rise of energy price and the still elevated housing prices, the policy to limit the share of housing expenses in the households' budget, so as to secure their solvability, has been criticized. Supposedly, it induces people to get farther from the city center in search for cheaper housing prices, but with subsequent increased transportation costs that are often disregarded during the house search process. Therefore, to improve the well-being of households, it has been advocated to set a constraint on the share of both housing and transportation expenditure. The paper is purported to analyze and compare the effects of the two policies in terms of: 1. Well-being of the households; 2. Land-use: city size and density curve; 3. Solvability of the households; 4. Transportation costs. The analysis is carried out within the classical monocentric model of urban economics. After setting a general analysis, an applied model is specified to capture the effects of each policy in straightforward formulae. It is shown that constraining housing expenses may increase the well-being of households. Besides, both policies prove effective in reducing urban sprawl and hereby energy consumption. Thus the choice of the optimal policy will depend on the local authority's objectives
Comment mesurer la précarité énergétique en matière de transport
National audienceSi des indicateurs existent pour quantifier la précarité énergétique dans le logement, leur simple transposition au domaine du transport n’est pas satisfaisante. Afin de mieux identifier les ménages vulnérables à une hausse des prix des carburants, un « indicateur Composite » est proposé. Il permet de mieux refléter les différents facteurs qui contraignent la mobilité des ménages et leurs possibilités d’adaptation
Investigating fuel poverty in the transport sector: toward a composite indicator of vulnerability
International audienceThis paper investigates the issue of fuel poverty and of its measurement in the transport sector. We seek to identify households who run the risk of facing difficulties if fuel prices increase. We show that fuel poverty indicators from the domestic sector are not satisfactory in this regard. They fail to take into account three specificities of the transport sector: (1) the diversity of travel needs, (2) restriction behaviours, and (3) variable capacities to adapt. We propose a composite indicator that targets factors of vulnerabilities. In contrast to the previous indicators, it does not solely focus on budgetary aspects but also reflects conditions of mobility. Three levels of exposition to rising fuel prices are considered, depending on the combinations of factors. We test this indicator on French data and find that 7,8% of French households are identified fuel poor, a further 7,4% fuel vulnerable and a further 3,7% fuel dependent
PRT Spidernet around rail hub for local empowerment of urban passenger transit: from conceptual design to simulation-based assessment methodology, with application to St Denis station of Grand Paris Express
The Spidernet concept consists in making a metropolitan, heavy rail station the hub of a web of elevated guided ways dedicated to small-size cabins driven automatically. Thus, comfortable point-to-point transport service would be provided to passengers, offering both speed and reliability (since its running would be uninterrupted), together with quick access and short wait at egress station were there sufficiently many " podcars ". This specific concept of Personal Rapid Transit (PRT) is purported to empower the local attraction of the heavy network and to develop the hub potential as service centre and urban centre. The paper investigates these issues in the case of the St Denis station in the Grand Paris Express network by the time horizon of implementation. After introducing the territorial context and putting forward a tentative scheme of Spidernet dedicated ways and stations, we turn to simulation to study potential demand, multimodal effects, fare sensitivity and potential revenues, as well as capital and operational costs. Two models are used complementarily: first, a macroscopic, four-step Travel Demand Model at the regional level; then, PRTSim is used for microscopic traffic simulation of both passengers and podcars. Microsimulation is essential to infer realistic enough traffic conditions on the supply side (way capacity, fleet size) as well as on the demand side (effective quality of service, wait time at access station, opportunity of car-sharing). The tentative estimation of revenues and costs suggests that financial profitability might be achieved. Yet a number of important topics still deserve further investigation
Euclidean distance versus travel time in business location: A probabilistic mixture of hurdle-Poisson models
While the question of the specification of spatial weight matrix is now largely discussed in the spatial econometrics literature, the definition of distance has attracted less attention. The choice of the distance measure is often glossed over, with the ultimate use of the Euclidean distance. This paper investigates this issue in the case of establishments locating in the Paris region. Indeed, numerous works highlight the importance of transport infrastructure in the location model, which challenges the choice of the Euclidean distance in representing spatial effects. To compare the various distance measures, we develop a probabilistic mixture of hurdle-Poisson models for several activity sectors. Each model class uses a different definition of distance to capture spatial spillovers. The following distance measures are considered: Euclidean distance, two road distances (with and without congestion), public transit distance, and the corresponding travel times. Overall, the obtained results are in line with the literature regarding the main determinants of establishments' location. However, we find that for some activity sectors, such as construction, the peak road travel time for private vehicles is the most likely to correctly capture spatial spillovers, whereas for other sectors, such as real estate, the Euclidean distance slightly prevails. This tends to show that spatial spillovers are channeled by different means, depending on the activity sector. In addition, we find that the proposed mixture of hurdle-Poisson models that uses several latent classes performs significantly better than the "pure" hurdle-Poisson models based on a single distance measure, emphasizing the usefulness of our approach
Observatory of Strategic Developments Impacting Urban Logistics (2017 version)
Urban freight living labs need to operate in full recognition of the challenges that will shape the mobility of goods in urban areas in the future. These challenges are several: macroeconomic, micro-economic, demographic, technological, societal, and legal. To help CITYLAB cities implement their urban freight initiatives, a better understanding of These challenges is necessary. This is what this Observatory of strategic developments impacting urban logistics intends to do, by providing data and analysis on some of the most important, or less well known, trends that will shape the urban mobility of goods in the future.
This second version (2017) of the Observatory provides data and analyses on 1) Logistics
Sprawl; 2) E-commerce; and 3) Service trips. Our findings about the main impacts of these three trends for cities involved in urban freight living labs are the following:
- The number of logistics facilities (in their diversity: warehouses, fulfilment centres, distribution centres, cross-dock terminals) is increasing in cities, especially cities of some logistics importance as large consumer markets and/or logistics hubs processing the flow of goods generated by the global economy. These facilities are generally located in suburban areas, but a new niche market of urban warehouses
is emerging.
- Both e-commerce and logistics sprawl generate a rise in freight vehicles in urban areas, dominated by small vehicles, while medium to large lorries are relatively less important. These vehicles performing delivery operations are visible in neighbourhoods and at times of day when they were not identified before: residential neighbourhoods, residential building blocks, side streets, in the early evening and on week-ends. Emerging new types of vehicles (clean delivery vehicles, two and three wheelers) are now visible in urban centres.
- Innovations in the urban supply chains include diverse forms of pick-up points and click-and-collect solutions, while the recent but extremely rapid rise in Technologies and algorithms supporting instant deliveries (on-demand deliveries within less than
two hours) brings with it a flourish of new companies connecting customers, suppliers and independent couriers, often using bicycles.
- The overall impact of these new trends on energy and carbon emission related to urban freight is difficult to assess. Urban freight in general, for the Paris region, brings the following environmental impact: the share of traffic-related CO2, NOx and PM10 due to urban freight is 2.5 times larger than the share of vans and trucks in the regional traffic. The contribution of urban freight to air pollution is larger in the city of Paris. Social costs of air pollution caused by road traffic in general amount to 0.9% of the regional GDP in 2012. Some of the new trends bring more CO2 emissions, such as the relocation of logistics facilities far away in the suburbs, as deconsolidated shipments are delivered to urban consumers and businesses in smaller and more numerous vans. Some trends bring less CO2 emissions, with a rise in cleaner vehicles and innovative solutions such as drop-off/pickup points or bikesupported instant deliveries. Substitution patterns between personal mobility and professional freight mobility can be a good, or a bad, thing for CO2 emissions, depending on the initial circumstances and the way personal shopping was done before online orders.
- What is certain is that these changes bring diversity in the urban traffic flow.
Instant couriers are using all sorts of transport modes, including foot, bicycles, electrically assisted cargocycles, motorbikes, and various types of vans and lorries.
This can negatively impact traffic management, road safety and conflicts in road uses, congestion, air pollution. Also, the trends we have looked at bring new types of urban jobs, with many unresolved legal issues and poor working conditions in many instances. New types of logistics buildings bring architectural diversity and innovation in cities, but also complaints about noise, aesthetics, as well as congestion and pollution at entrance and exit points.
- These environmental and social impacts have been so far poorly documented and researched. Consumers are the main drivers of the changes we have observed, but they are also the residents or visitors of urban areas, and for that they carry an important share of the burdens, as well as the benefits, of the new landscape of urban logistics.
- Service trips are trips in commercial traffic induced by service oriented activities.
According to the German study KiD 2010 service traffic accounts for 11.8% of traffic
in terms of trips and for 19.9% in terms of kilometres travelled. There are differences in terms of vehicle types and economic sectors but few variations in Terms of spatial types.
- An observatory on service traffic must take into account light duty vehicles and passenger cars in general. Establishment based analysis as well as vehicle based
analysis can give detailed insight in traffic generation and traffic behaviour in Service traffic
A New Look at the Environmental Assessment of Logistics Sprawl Part 1: The Environmental Impact of Urban Road Freight: A Modeling Exercise for the Paris Region [Brief]
This research aims at improving knowledge on the environmental impacts of urban road freight (URF). It questions the gap between common beliefs about the environmental impact of URF and its specific empirical measurement
Editorial: Household transport costs, economic stress and energy vulnerability
International audienceSince the early 2000s issues of transport poverty and social exclusion have received increasing attention in transport studies (Dodson et al., 2004; Hine and Mitchell, 2001; Lucas et al., 2001). Although much of this research has focused on low-mobility and/or carless individuals, there has been growing awareness that the costs of daily mobility can have important economic stress impacts. In developed countries with high levels of car dependence, the costs of motoring can be burdensome, raising questions of affordability for households with limited economic resources.A number of developments in the first two decades of this century have contributed to raise the profile of household transport costs as a research topic and a policy concern. First, and more obviously, increasing and increasingly volatile global oil prices have raised concerns for the vulnerability of households to fuel price increases (Dodson and Sipe, 2007). Second, the rise of the climate change agenda has led to consider pricing measures as a key component of sustainable transport policy. Implementation of such measures however, has often been hampered by concerns for the distributional impacts of increasing transport costs faced by households. Third, the global financial crisis of 2007–2008 and its aftermath have highlighted broader issues of living standards, economic stress and affordability, which go beyond the specific case of transport.In this context, a further reason to investigate household transport costs has to do with other competing pressures on household budgets
Transport poverty and fuel poverty in the UK: From analogy to comparison
The notion of ’fuel poverty’, referring to affordable warmth, underpins established research and policy agendas in the UK and has been extremely influential worldwide. In this context, British researchers, official policymaking bodies and NGOs have put forward the notion of ’transport poverty’, building on an implicit analogy between (recognised) fuel poverty and (neglected) transport affordability issues. However, the conceptual similarities and differences between ’fuel’ and ’transport’ poverty remain largely unaddressed in the UK. This paper systematically compares and contrasts the two concepts, examining critically the assumption of a simple equivalence between them. We illustrate similarities and differences under four headings: (i) negative consequences of lack of warmth and lack of access; (ii) drivers of fuel and transport poverty; (iii) definition and measurement; (iv) policy interventions. Our review suggests that there are important conceptual and practical differences between transport and domestic energy consumption, with crucial consequences for how affordability problems amongst households are to be conceptualised and addressed. In a context where transport and energy exhibit two parallel policy worlds, the analysis in the paper and these conclusions reinforce how and why these differences matter. As we embark on an ever closer union between our domestic energy and transport energy systems the importance of these contradictions will become increasingly evident and problematic. This work contributes to the long-term debate about how best to manage these issues in a radical energy transition that properly pays attention to issues of equity and affordability
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