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To a client, taxi quality of service involves not only the riding time and comfort, but also the access time between the instants of booking (or readying oneself) and pickup. In turn, the access time depends on fleet size and the macroscopic patterns of service usage: demand volume and its spread in space, average ride time, transaction times. In this article, we investigate the formation of the access time and derive its economic consequences for a taxi service in an idealized city with ring shape and spatial homogeneity, hence circular symmetry. At the operational level, under given supply and demand conditions the access time stems from the number of busy vehicles, which obeys to a second-degree characteristic equation. This enables us to model fleet size as a function of target demand volume and access time. Taking then a broader perspective, demand is elastic to supply conditions including access time, ride time, transaction time and tariff fare. We model short-term traffic equilibrium and demonstrate the existence and uniqueness of an equilibrium state. Next, at the tactical level the service supplier sets up the fleet size and the tariff fare in order to satisfy an economic objective. We model medium-term supply-demand equilibrium under three regulation patterns of, respectively, (i) service monopoly and the maximization of production profit, (ii) system optimum and the maximization of social surplus, (iii) second best system optimum subject to a budgetary constraint. In each pattern, both the tariff fare and the access time are linked by analytical formulas to exogenous conditions about the territory, the demand and the cost function of service provision. Theoretical properties are obtained to compare the patterns under specific demand function with constant elasticity of volume to generalized cost: under constant elasticity of-2, the monopoly tariff and generalized cost are more than twice as large as their system optimum counterparts, and exact doubles of their second best optimum counterparts in the absence of fixed production costs. At the strategic level, the model can be applied to assess decisions on vehicle technology (motor type, driving technology) and on service location by the service supplier, as well as the regulation policies by public authorities.

To a client, taxi quality of service involves not only the riding time and comfort, but also the access time between the instants of booking (or readying oneself) and pickup. In turn, the access time depends on fleet size and the macroscopic patterns of service usage: demand volume and its spread in space, average ride time, transaction times. In this article, we investigate the formation of the access time and derive its economic consequences for a taxi service in an idealized city with ring shape and spatial homogeneity, hence circular symmetry. At the operational level, under given supply and demand conditions the access time stems from the number of busy vehicles, which obeys to a second-degree characteristic equation. This enables us to model fleet size as a function of target demand volume and access time. Taking then a broader perspective, demand is elastic to supply conditions including access time, ride time, transaction time and tariff fare. We model short-term traffic equilibrium and demonstrate the existence and uniqueness of an equilibrium state. Next, at the tactical level the service supplier sets up the fleet size and the tariff fare in order to satisfy an economic objective. We model medium-term supply-demand equilibrium under three regulation patterns of, respectively, (i) service monopoly and the maximization of production profit, (ii) system optimum and the maximization of social surplus, (iii) second best system optimum subject to a budgetary constraint. In each pattern, both the tariff fare and the access time are linked by analytical formulas to exogenous conditions about the territory, the demand and the cost function of service provision. Theoretical properties are obtained to compare the patterns under specific demand function with constant elasticity of volume to generalized cost: under constant elasticity of-2, the monopoly tariff and generalized cost are more than twice as large as their system optimum counterparts, and exact doubles of their second best optimum counterparts in the ...

To a client, taxi quality of service involves not only the riding time and comfort, but also the access time between the instants of booking (or readying oneself) and pickup. In turn, the access time depends on fleet size and the macroscopic patterns of service usage: demand volume and its spread in space, average ride time, transaction times. In this article, we investigate the formation of the access time and derive its economic consequences for a taxi service in an idealized city with ring shape and spatial homogeneity, hence circular symmetry. At the operational level, under given supply and demand conditions the access time stems from the number of busy vehicles, which obeys to a second-degree characteristic equation. This enables us to model fleet size as a function of target demand volume and access time. Taking then a broader perspective, demand is elastic to supply conditions including access time, ride time, transaction time and tariff fare. We model short-term traffic equilibrium and demonstrate the existence and uniqueness of an equilibrium state. Next, at the tactical level the service supplier sets up the fleet size and the tariff fare in order to satisfy an economic objective. We model medium-term supply-demand equilibrium under three regulation patterns of, respectively, (i) service monopoly and the maximization of production profit, (ii) system optimum and the maximization of social surplus, (iii) second best system optimum subject to a budgetary constraint. In each pattern, both the tariff fare and the access time are linked by analytical formulas to exogenous conditions about the territory, the demand and the cost function of service provision. Theoretical properties are obtained to compare the patterns under specific demand function with constant elasticity of volume to generalized cost: under constant elasticity of-2, the monopoly tariff and generalized cost are more than twice as large as their system optimum counterparts, and exact doubles of their second best optimum counterparts in the absence of fixed production costs. At the strategic level, the model can be applied to assess decisions on vehicle technology (motor type, driving technology) and on service location by the service supplier, as well as the regulation policies by public authorities.

In Île-de-France, the high level of property prices translates into a higher share of income devoted to housing than in the province. In this context, rising fuel prices could weigh on households' creditworthiness. Several authors argue that this risk is increased in peri-urban and rural areas. Remoteness from Paris would entail significant transport costs in addition to an already high housing budget. However, the monocentric model of the urban economy contradicts this statement at the very least. This model predicts that transport and housing budgets will be fungible, from partial to total depending on the assumptions made. The high transport costs in remote areas would therefore be offset by a lower housing budget. This study tests the predictions of the monocentric model regarding the fungibility of housing and transport budgets in the case of francial households. The information contained in the Global Transport Survey 2001-2002 makes it possible to develop a simple econometric test (i.e. the transport cost variable in the housing expenditure equation), but not so far. With a given occupancy status, income is the main determinant of the housing budget, with other household characteristics having a secondary impact. The different transport cost variables tested are insignificant or of marginal influence. In particular, the elasticity of the housing budget to the transport budget is zero for households accessing private ownership and tenants, and slightly positive (0,025) in the social sector. These results lead to the rejection of the assumption of a trade-off between the cost of accommodation and the cost of transport. As an annex, the study finds a positive link between housing expenditure and prices per m². This calls into question the frequent choice of Cobb-Douglas utility functions to model households' residential preferences. ; International audience ; In Île-de-France, the high level of property prices translates into a higher share of income devoted to housing than in the province. In this context, ...

International audience ; The development of electro-mobility, with electric motors replacing the internal combustion engine, raises issues relating to the environment, energy and industry. Within a given country, it would have an economic and social impact in many areas, in particular on governments. Our objective is to quantify the respective impacts on the public finances of an electrically powered or petrol fuelled private car. In order to do this, we establish an integrated method of valuation, covering both manufacture and use of the vehicle, which locates these stages within or outside the country concerned. From a "depth" perspective, it incorporates the economic proceeds from the different activities and what they consume, and from a "breadth" perspective it incorporates the fiscal effects (VAT, fuel and energy taxes, tax on production, etc.) and the social effects (social contributions, unemployment benefits). The valuation method is based on an input-output model of the productive economy within a country, combined with mechanisms of fiscal and social transfer. We postulate the existence of an activity for the Manufacture of electric vehicles, and we include this within the consumption matrix associated with production. We apply this method to France, and to a diverse range of scenarios regarding the place in which the vehicle is manufactured and used. From this assessment it emerges that the impact of a vehicle on the public finances is substantial: manufacture contributes approximately the purchase price excluding VAT, and usage adds an amount of the same order of magnitude. The vast majority of the revenues arise from the social contributions associated with production (approximately 70%); VAT accounts for almost 20%, tax on production around 5%, and energy surcharge 9% for an internal combustion vehicle or 1% for an electric vehicle. If it is both manufactured and used inside the country, then an electric vehicle might contribute very slightly more to the public finances than an internal combustion vehicle, before any purchase incentive bonus, which would markedly reverse the outcome. The worst scenario would be the use of an imported electric vehicle instead of a domestically manufactured internal combustion vehicle. At the other end of the scale, as an export product, an electric vehicle contributes substantially more to the public purse than an internal combustion vehicle.

International audience ; The development of electro-mobility, with electric motors replacing the internal combustion engine, raises issues relating to the environment, energy and industry. Within a given country, it would have an economic and social impact in many areas, in particular on governments. Our objective is to quantify the respective impacts on the public finances of an electrically powered or petrol fuelled private car. In order to do this, we establish an integrated method of valuation, covering both manufacture and use of the vehicle, which locates these stages within or outside the country concerned. From a "depth" perspective, it incorporates the economic proceeds from the different activities and what they consume, and from a "breadth" perspective it incorporates the fiscal effects (VAT, fuel and energy taxes, tax on production, etc.) and the social effects (social contributions, unemployment benefits). The valuation method is based on an input-output model of the productive economy within a country, combined with mechanisms of fiscal and social transfer. We postulate the existence of an activity for the Manufacture of electric vehicles, and we include this within the consumption matrix associated with production. We apply this method to France, and to a diverse range of scenarios regarding the place in which the vehicle is manufactured and used. From this assessment it emerges that the impact of a vehicle on the public finances is substantial: manufacture contributes approximately the purchase price excluding VAT, and usage adds an amount of the same order of magnitude. The vast majority of the revenues arise from the social contributions associated with production (approximately 70%); VAT accounts for almost 20%, tax on production around 5%, and energy surcharge 9% for an internal combustion vehicle or 1% for an electric vehicle. If it is both manufactured and used inside the country, then an electric vehicle might contribute very slightly more to the public finances than an internal combustion vehicle, before any purchase incentive bonus, which would markedly reverse the outcome. The worst scenario would be the use of an imported electric vehicle instead of a domestically manufactured internal combustion vehicle. At the other end of the scale, as an export product, an electric vehicle contributes substantially more to the public purse than an internal combustion vehicle.

International audience ; Depuis quelques années, le véhicule électrique (VE) suscite un très important regain d'intérêt, au titre de divers enjeux d'ordre aussi bien écologique (qualité de l'air, bruit, émissions de gaz à effet de serre) qu'économique, pour revitaliser l'industrie automobile et à travers elle la production économique générale, ou encor énergétique, pour réduire la dépendance aux carburants importés. C'est pourquoi les pouvoirs publics promeuvent le développement de la mobilité électrique. Les acheteurs de VE bénéficient dès aujourd'hui de réductions de taxes et de fortes subventions à l'achat. Les fournisseurs de l'infrastructure de recharge profitent de nouvelles réglementations et de subventions de la part de l'Etat. Des prévisions de la demande en VE sont absolument nécessaires pour anticiper les économies d'échelle dans l'industrie et déterminer le prix de vente par voiture, ainsi que pour dimensionner les consommations de ressources. Leur élaboration est soumise à la complexité du système de mobilité électrique, dont les circonstances subissent une évolution permanente et parfois peu prévisible (ex. en ce qui concerne le prix du carburant) ; et aussi parce que la demande en véhicules dépendra fortement des politiques publiques. Les études antérieures qui explorent la demande en VE masquent souvent cette complexité systémique. L'interrelation entre les politiques publiques et la demande n'est pas prise en compte. Des modèles agrégés sont conçus pour des régions vastes (comme tout un pays) et servent ensuite à établir des prévisions plutôt contestables. Des paramètres désagrégés, tels que les caractéristiques des ménages ou du territoire analysé, restent bien souvent ignorés, alors qu'ils jouent un rôle important dans le bilan financier pour un ménage. Cette étude a pour but de mieux comprendre l'impact des paramètres désagrégés sur le choix d'équipement des ménages. Nous nous plaçons dans la perspective d'un ménage particulier résidant en Ile-de-France, et nous menons une analyse économique ...

International audience ; The development of electro-mobility, with electric motors replacing the internal combustion engine, raises issues relating to the environment, energy and industry. Within a given country, it would have an economic and social impact in many areas, in particular on governments. Our objective is to quantify the respective impacts on the public finances of an electrically powered or petrol fuelled private car. In order to do this, we establish an integrated method of valuation, covering both manufacture and use of the vehicle, which locates these stages within or outside the country concerned. From a "depth" perspective, it incorporates the economic proceeds from the different activities and what they consume, and from a "breadth" perspective it incorporates the fiscal effects (VAT, fuel and energy taxes, tax on production, etc.) and the social effects (social contributions, unemployment benefits). The valuation method is based on an input-output model of the productive economy within a country, combined with mechanisms of fiscal and social transfer. We postulate the existence of an activity for the Manufacture of electric vehicles, and we include this within the consumption matrix associated with production. We apply this method to France, and to a diverse range of scenarios regarding the place in which the vehicle is manufactured and used. From this assessment it emerges that the impact of a vehicle on the public finances is substantial: manufacture contributes approximately the purchase price excluding VAT, and usage adds an amount of the same order of magnitude. The vast majority of the revenues arise from the social contributions associated with production (approximately 70%); VAT accounts for almost 20%, tax on production around 5%, and energy surcharge 9% for an internal combustion vehicle or 1% for an electric vehicle. If it is both manufactured and used inside the country, then an electric vehicle might contribute very slightly more to the public finances than an internal combustion ...

International audience ; Depuis quelques années, le véhicule électrique (VE) suscite un très important regain d'intérêt, au titre de divers enjeux d'ordre aussi bien écologique (qualité de l'air, bruit, émissions de gaz à effet de serre) qu'économique, pour revitaliser l'industrie automobile et à travers elle la production économique générale, ou encor énergétique, pour réduire la dépendance aux carburants importés. C'est pourquoi les pouvoirs publics promeuvent le développement de la mobilité électrique. Les acheteurs de VE bénéficient dès aujourd'hui de réductions de taxes et de fortes subventions à l'achat. Les fournisseurs de l'infrastructure de recharge profitent de nouvelles réglementations et de subventions de la part de l'Etat. Des prévisions de la demande en VE sont absolument nécessaires pour anticiper les économies d'échelle dans l'industrie et déterminer le prix de vente par voiture, ainsi que pour dimensionner les consommations de ressources. Leur élaboration est soumise à la complexité du système de mobilité électrique, dont les circonstances subissent une évolution permanente et parfois peu prévisible (ex. en ce qui concerne le prix du carburant) ; et aussi parce que la demande en véhicules dépendra fortement des politiques publiques. Les études antérieures qui explorent la demande en VE masquent souvent cette complexité systémique. L'interrelation entre les politiques publiques et la demande n'est pas prise en compte. Des modèles agrégés sont conçus pour des régions vastes (comme tout un pays) et servent ensuite à établir des prévisions plutôt contestables. Des paramètres désagrégés, tels que les caractéristiques des ménages ou du territoire analysé, restent bien souvent ignorés, alors qu'ils jouent un rôle important dans le bilan financier pour un ménage. Cette étude a pour but de mieux comprendre l'impact des paramètres désagrégés sur le choix d'équipement des ménages. Nous nous plaçons dans la perspective d'un ménage particulier résidant en Ile-de-France, et nous menons une analyse économique par type de véhicule, thermique ou électrique, en termes de coûts totaux de détention. Le modèle est conçu sous une forme flexible et permet l'analyse de scénarios divers. Nous investiguons les impacts de paramètres désagrégés, de politiques publiques et du développement de marché. De plus, chaque scénario fait l'objet d'une analyse de " point mort ": quel est le kilométrage annuel, et/ou le prix de carburant, nécessaire pour rendre le VE plus avantageux que son concurrent thermique ? Les résultats démontrent l'importance déterminante des paramètres désagrégés dans la prospection de la demande.

International audience ; Depuis quelques années, le véhicule électrique (VE) suscite un très important regain d'intérêt, au titre de divers enjeux d'ordre aussi bien écologique (qualité de l'air, bruit, émissions de gaz à effet de serre) qu'économique, pour revitaliser l'industrie automobile et à travers elle la production économique générale, ou encor énergétique, pour réduire la dépendance aux carburants importés. C'est pourquoi les pouvoirs publics promeuvent le développement de la mobilité électrique. Les acheteurs de VE bénéficient dès aujourd'hui de réductions de taxes et de fortes subventions à l'achat. Les fournisseurs de l'infrastructure de recharge profitent de nouvelles réglementations et de subventions de la part de l'Etat. Des prévisions de la demande en VE sont absolument nécessaires pour anticiper les économies d'échelle dans l'industrie et déterminer le prix de vente par voiture, ainsi que pour dimensionner les consommations de ressources. Leur élaboration est soumise à la complexité du système de mobilité électrique, dont les circonstances subissent une évolution permanente et parfois peu prévisible (ex. en ce qui concerne le prix du carburant) ; et aussi parce que la demande en véhicules dépendra fortement des politiques publiques. Les études antérieures qui explorent la demande en VE masquent souvent cette complexité systémique. L'interrelation entre les politiques publiques et la demande n'est pas prise en compte. Des modèles agrégés sont conçus pour des régions vastes (comme tout un pays) et servent ensuite à établir des prévisions plutôt contestables. Des paramètres désagrégés, tels que les caractéristiques des ménages ou du territoire analysé, restent bien souvent ignorés, alors qu'ils jouent un rôle important dans le bilan financier pour un ménage. Cette étude a pour but de mieux comprendre l'impact des paramètres désagrégés sur le choix d'équipement des ménages. Nous nous plaçons dans la perspective d'un ménage particulier résidant en Ile-de-France, et nous menons une analyse économique par type de véhicule, thermique ou électrique, en termes de coûts totaux de détention. Le modèle est conçu sous une forme flexible et permet l'analyse de scénarios divers. Nous investiguons les impacts de paramètres désagrégés, de politiques publiques et du développement de marché. De plus, chaque scénario fait l'objet d'une analyse de " point mort ": quel est le kilométrage annuel, et/ou le prix de carburant, nécessaire pour rendre le VE plus avantageux que son concurrent thermique ? Les résultats démontrent l'importance déterminante des paramètres désagrégés dans la prospection de la demande.

The paper provides a synthetic, "strategic" model of transit systems in urban areas that features out a set of modes, quality of service and terminal access, demand and network usage by users' trips, with some hints of spatial heterogeneity. The model encompasses technical relationships relating fleet size and design parameters such as infrastructure length and station spacing, to frequency, commercial speed and access distance, hence to wait time, running time and access/egress time. Economic features are modelled, too: generalized costs to individual users, demand elasticity, supply costs and system welfare. The model can be used for synthetic statistical description of real-world systems as well as for economic analysis and the assessment of given system states against theoretical references. After introducing the model elements and relationships, we put forward a causal diagram that synthesizes the system under study and constitutes the model architecture. We then turn to mathematical analysis to formalize (i) the determination of a system state on the basis of a supply plan, technical relationships and demand behaviour, (ii) the optimisation of system welfare with respect to the action levers on the supply side. Next, for an uncongested system we establish theoretical conditions for both an optimum system state under fixed demand and a second best optimum under variable demand and tariffs. Three "golden rules" for transit network design and management are established, namely (i) balancing the rolling stock costs and the users' costs of waiting time, (ii) balancing the station costs plus the value to users of the dwelling part of their in-network times, against the users' costs of "longitudinal" access times, (iii) balancing the full supply costs and the users' costs of "transversal" access times. Furthermore, the existence and uniqueness of a System Optimum state are proven and a solution scheme is provided.

The paper provides a synthetic, "strategic" model of transit systems in urban areas that features out a set of modes, quality of service and terminal access, demand and network usage by users' trips, with some hints of spatial heterogeneity. The model encompasses technical relationships relating fleet size and design parameters such as infrastructure length and station spacing, to frequency, commercial speed and access distance, hence to wait time, running time and access/egress time. Economic features are modelled, too: generalized costs to individual users, demand elasticity, supply costs and system welfare. The model can be used for synthetic statistical description of real-world systems as well as for economic analysis and the assessment of given system states against theoretical references. After introducing the model elements and relationships, we put forward a causal diagram that synthesizes the system under study and constitutes the model architecture. We then turn to mathematical analysis to formalize (i) the determination of a system state on the basis of a supply plan, technical relationships and demand behaviour, (ii) the optimisation of system welfare with respect to the action levers on the supply side. Next, for an uncongested system we establish theoretical conditions for both an optimum system state under fixed demand and a second best optimum under variable demand and tariffs. Three "golden rules" for transit network design and management are established, namely (i) balancing the rolling stock costs and the users' costs of waiting time, (ii) balancing the station costs plus the value to users of the dwelling part of their in-network times, against the users' costs of "longitudinal" access times, (iii) balancing the full supply costs and the users' costs of "transversal" access times. Furthermore, the existence and uniqueness of a System Optimum state are proven and a solution scheme is provided.

The paper provides a synthetic, "strategic" model of transit systems in urban areas that features out a set of modes, quality of service and terminal access, demand and network usage by users' trips, with some hints of spatial heterogeneity. The model encompasses technical relationships relating fleet size and design parameters such as infrastructure length and station spacing, to frequency, commercial speed and access distance, hence to wait time, running time and access/egress time. Economic features are modelled, too: generalized costs to individual users, demand elasticity, supply costs and system welfare. The model can be used for synthetic statistical description of real-world systems as well as for economic analysis and the assessment of given system states against theoretical references. After introducing the model elements and relationships, we put forward a causal diagram that synthesizes the system under study and constitutes the model architecture. We then turn to mathematical analysis to formalize (i) the determination of a system state on the basis of a supply plan, technical relationships and demand behaviour, (ii) the optimisation of system welfare with respect to the action levers on the supply side. Next, for an uncongested system we establish theoretical conditions for both an optimum system state under fixed demand and a second best optimum under variable demand and tariffs. Three "golden rules" for transit network design and management are established, namely (i) balancing the rolling stock costs and the users' costs of waiting time, (ii) balancing the station costs plus the value to users of the dwelling part of their in-network times, against the users' costs of "longitudinal" access times, (iii) balancing the full supply costs and the users' costs of "transversal" access times. Furthermore, the existence and uniqueness of a System Optimum state are proven and a solution scheme is provided.

The paper provides a synthetic, "strategic" model of transit systems in urban areas that features out a set of modes, quality of service and terminal access, demand and network usage by users' trips, with some hints of spatial heterogeneity. The model encompasses technical relationships relating fleet size and design parameters such as infrastructure length and station spacing, to frequency, commercial speed and access distance, hence to wait time, running time and access/egress time. Economic features are modelled, too: generalized costs to individual users, demand elasticity, supply costs and system welfare. The model can be used for synthetic statistical description of real-world systems as well as for economic analysis and the assessment of given system states against theoretical references. After introducing the model elements and relationships, we put forward a causal diagram that synthesizes the system under study and constitutes the model architecture. We then turn to mathematical analysis to formalize (i) the determination of a system state on the basis of a supply plan, technical relationships and demand behaviour, (ii) the optimisation of system welfare with respect to the action levers on the supply side. Next, for an uncongested system we establish theoretical conditions for both an optimum system state under fixed demand and a second best optimum under variable demand and tariffs. Three "golden rules" for transit network design and management are established, namely (i) balancing the rolling stock costs and the users' costs of waiting time, (ii) balancing the station costs plus the value to users of the dwelling part of their in-network times, against the users' costs of "longitudinal" access times, (iii) balancing the full supply costs and the users' costs of "transversal" access times. Furthermore, the existence and uniqueness of a System Optimum state are proven and a solution scheme is provided.