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Autonomous vehicles promise to revolutionize the automobile market, although their implementation could take several decades in which both types of cars will coexist on the streets. We formulate a model for a circular city based on continuous approximations, considering demand surfaces over the city. Numerical results from our model predict direct and indirect effects of connected and autonomous vehicles. Direct effects will be positive for our cities: (a) less street supply is needed to accommodate the traffic; (b) congestion levels decrease: travel costs may decrease by 30%. Some indirect effects will counterbalance these positive effects: (c) a decrease of 20% in the value of travel time can reduce the total cost by a third; (d) induced demand could be as high as 50%, bringing equivalent total costs in the future scenario; (e) the vehicle-kilometers traveled could also affect the future scenario; and (f) increases in city size and urban sprawl. As a conclusion, the implementation of autonomous vehicles could be neutral for the cities regarding travel time costs. City planning agencies still have to promote complementary modes such as active mobility (walking and bicycle), transit (public transportation), and shared mobility (shared autonomous vehicles and mobility as a service).
Marcos Medina-Tapia; Francesc Robusté. Implementation of Connected and Autonomous Vehicles in Cities Could Have Neutral Effects on the Total Travel Time Costs: Modeling and Analysis for a Circular City. Sustainability 2019, 11, 482 .
AMA StyleMarcos Medina-Tapia, Francesc Robusté. Implementation of Connected and Autonomous Vehicles in Cities Could Have Neutral Effects on the Total Travel Time Costs: Modeling and Analysis for a Circular City. Sustainability. 2019; 11 (2):482.
Chicago/Turabian StyleMarcos Medina-Tapia; Francesc Robusté. 2019. "Implementation of Connected and Autonomous Vehicles in Cities Could Have Neutral Effects on the Total Travel Time Costs: Modeling and Analysis for a Circular City." Sustainability 11, no. 2: 482.
Night distribution and consolidation strategies have been proposed in many cities to increase the efficiency of the urban goods distribution system and to reduce the external effects that it causes in terms of emissions. However, the deployment of these initiatives presents a new reallocation of costs and incomes among collaborative stakeholders that take part in. In this paper, an analytical model to estimate the new economic effects caused by these strategies on the involved agents is presented, based on continuous approximations. This model allows decision makers to estimate the transportation cost and emissions savings that will be obtained by each strategy as well as the range of retailer demand in which these strategies are not economically feasible. The results show that night distribution generally outperforms the carrier cost reduction and emissions savings, especially when large vehicles are used in night periods.
Miquel Estrada; José Magín Campos Cacheda; Francesc Robusté. NIGHT DELIVERIES AND CARRIER-LED CONSOLIDATION STRATEGIES TO IMPROVE URBAN GOODS DISTRIBUTION. Transport 2018, 33, 930 -947.
AMA StyleMiquel Estrada, José Magín Campos Cacheda, Francesc Robusté. NIGHT DELIVERIES AND CARRIER-LED CONSOLIDATION STRATEGIES TO IMPROVE URBAN GOODS DISTRIBUTION. Transport. 2018; 33 (4):930-947.
Chicago/Turabian StyleMiquel Estrada; José Magín Campos Cacheda; Francesc Robusté. 2018. "NIGHT DELIVERIES AND CARRIER-LED CONSOLIDATION STRATEGIES TO IMPROVE URBAN GOODS DISTRIBUTION." Transport 33, no. 4: 930-947.
Urban mobility is a dynamic system that has had a (slow) natural evolution. Scientists and engineers are currently developing new mobility technologies. A progressive paradigm shift will change everything from the fuel type to the way of driving vehicles. Vehicles will progressively become autonomous and will communicate and cooperate with each other. In the long run, profound changes are expected in mobility as a service. Furthermore, urban areas will have a higher level of development, and cities will likely turn into Smart Cities in which the vehicles will interact with the urban infrastructure. The main objective of this paper is to explore the macroscopic effects of mobility interaction in a radial-circular urban road system for current and future cities (Smart Cities). In the literature, there is documentation of the direct effects of autonomous vehicles, but some indirect effects will cause undesirable impacts such as an increase in demand and more congestion, which change the demand behavior and the urban structure. Finally, this paper exhibits the results of direct and indirect effects calculated through analytical tools (Continuous Approximation Method). In fact, our research shows that if demand increases by about 50%, the current scenario could have the same total cost as the future scenario with autonomous vehicles. Moreover, if the city radius increases by about 33% and the subjective value of time decreases about 20%, the benefits of the autonomous cars will be compensated. Therefore, the paper proves that autonomous vehicles could encourage the urban sprawl in the long run. Finally, Administrations should define transport strategies and policies to control these externalities, because autonomous driving could deteriorate mobility even worse than it is now.
Marcos Medina-Tapia; Francesc Robusté. Exploring paradigm shift impacts in urban mobility: Autonomous Vehicles and Smart Cities. Transportation Research Procedia 2018, 33, 203 -210.
AMA StyleMarcos Medina-Tapia, Francesc Robusté. Exploring paradigm shift impacts in urban mobility: Autonomous Vehicles and Smart Cities. Transportation Research Procedia. 2018; 33 ():203-210.
Chicago/Turabian StyleMarcos Medina-Tapia; Francesc Robusté. 2018. "Exploring paradigm shift impacts in urban mobility: Autonomous Vehicles and Smart Cities." Transportation Research Procedia 33, no. : 203-210.
Travel time and activity time have been treated as separate notions, albeit with some assumed interdependencies. But, previous studies show that people accept noticeable higher travel time ratios when travelling by public transport compared with travelling by car. The cost of travel time is reduced as travel time is converted as activity time (towards the productive use). Furthermore, the impact of a high quality journey is an important issue in lifestyle and distribution of activities. The efficiency, safety and productivity of the journey can be expected to impact the value of time. And, the proportion of travel time saved, which can be used for other activities might have positive effects on the quality of life. In recent years some significant ICT-related innovations have been introduced to large shares of society, but research on the current relation between characteristics of ICT-use and its impact on mobility is limited. Development of smart cities and urban living labs is strongly affected by the ICT use and mobility patterns, as urban living labs co-create new products from collaboration between public, private and civic partnerships. At the same time, in certain self-constrained environments, activity duration has many effects in travel patterns for out-ofhome activities. Use of big data to model travel behaviour might bring important implications for individual mobility. Similarly, traffic safety and management of transport infrastructure are a main concern for government decisions in developing countries. This paper contains a summary of five keynote sessions of the Symposium Smart Cities and Value of Time, that took place in Santo Domingo, Dominican Republic in January 18 and 19 2018. This symposium aimed to contribute to the debate on planning transport system and urban development according to the needs and activities undertaken by citizens of the modern ‘on move’ society. This summary presents five key points of transport research oriented to smart cities and value of time, which can be mentioned as: user’s perspective (equity), data collection and infrastructure (traffic safety and network design). These topics are substantially important to estimate accurate travel demand models, and therefore design efficient transport measures.
Karst Geurs; Francesc Robusté; Lissy La Paix; Thais Rangel; John Pritchard. Smart cities and value of time: An International Symposium. Ciencia, Ingenierías y Aplicaciones 2018, 1, 71 -78.
AMA StyleKarst Geurs, Francesc Robusté, Lissy La Paix, Thais Rangel, John Pritchard. Smart cities and value of time: An International Symposium. Ciencia, Ingenierías y Aplicaciones. 2018; 1 (1):71-78.
Chicago/Turabian StyleKarst Geurs; Francesc Robusté; Lissy La Paix; Thais Rangel; John Pritchard. 2018. "Smart cities and value of time: An International Symposium." Ciencia, Ingenierías y Aplicaciones 1, no. 1: 71-78.
Las paradas de transporte público (TP), tanto en su distribución como en su localización, son generalmente analizadas desde un punto de vista macroscópico, utilizando modelos analíticos para observar tanto una línea de buses, en particular, o la red de transporte público, en general. Sin embargo, la importancia y complejidad de lograr una buena operación de las paradas de transporte público y en particular lograr que éstas tengan una buena accesibilidad, requiere de un análisis más detallado. Actualmente no existen desarrollos metodológicos que solucionen este problema, menos aún en el caso de proyectos viales de mejora de la infraestructura urbana que implican una intervención importante de un sector de la ciudad, por lo que en este trabajo se propone una metodología de localización de paradas de transporte público que a través de un modelo matemático de optimización permita ubicar dichos paraderos provisorios a lo largo de las calles propuestas en un Plan de Desvíos de manera tal de optimizar la accesibilidad de los usuarios al transporte público. Esta metodología fue aplicada a un caso real de estudio en la intersección de las avenidas 5 de Abril – Esquina Blanca con Avenida Del Ferrocarril de Santiago, Chile, y los resultados muestran que se puede mantener y, en algunos casos, mejorar el nivel de servicio del transporte público desde el punto de vista de la accesibilidad al mismo. Por lo tanto, se demuestra la importancia y el aporte que esta metodología puede tener para mejorar la planificación de los Planes de Desvío por obras de mejoramiento vial al incorporar la variable accesibilidad al transporte público.DOI: http://dx.doi.org/10.4995/CIT2016.2016.4253
Marcos Medina-Tapia; Cristian Baeza; Daniel Arancibia; Francesc Robusté. Relocalización de paradas de transporte público para ser incorporado dentro planes de contingencia como resultado de la construcción de obras de mejora vial. Libro de Actas CIT2016. XII Congreso de Ingeniería del Transporte 2016, 1 .
AMA StyleMarcos Medina-Tapia, Cristian Baeza, Daniel Arancibia, Francesc Robusté. Relocalización de paradas de transporte público para ser incorporado dentro planes de contingencia como resultado de la construcción de obras de mejora vial. Libro de Actas CIT2016. XII Congreso de Ingeniería del Transporte. 2016; ():1.
Chicago/Turabian StyleMarcos Medina-Tapia; Cristian Baeza; Daniel Arancibia; Francesc Robusté. 2016. "Relocalización de paradas de transporte público para ser incorporado dentro planes de contingencia como resultado de la construcción de obras de mejora vial." Libro de Actas CIT2016. XII Congreso de Ingeniería del Transporte , no. : 1.
Hugo Badia; Miquel Estrada; Francesc Robusté. Competitive transit network design in cities with radial street patterns. Transportation Research Part B: Methodological 2014, 59, 161 -181.
AMA StyleHugo Badia, Miquel Estrada, Francesc Robusté. Competitive transit network design in cities with radial street patterns. Transportation Research Part B: Methodological. 2014; 59 ():161-181.
Chicago/Turabian StyleHugo Badia; Miquel Estrada; Francesc Robusté. 2014. "Competitive transit network design in cities with radial street patterns." Transportation Research Part B: Methodological 59, no. : 161-181.
Miquel Estrada; Francesc Robusté; Jordi Amat; Hugo Badia; Jaume Barcelo. Optimal Length of Transit Network with Traffic Performance Microsimulation. Transportation Research Record: Journal of the Transportation Research Board 2012, 2276, 9 -16.
AMA StyleMiquel Estrada, Francesc Robusté, Jordi Amat, Hugo Badia, Jaume Barcelo. Optimal Length of Transit Network with Traffic Performance Microsimulation. Transportation Research Record: Journal of the Transportation Research Board. 2012; 2276 (1):9-16.
Chicago/Turabian StyleMiquel Estrada; Francesc Robusté; Jordi Amat; Hugo Badia; Jaume Barcelo. 2012. "Optimal Length of Transit Network with Traffic Performance Microsimulation." Transportation Research Record: Journal of the Transportation Research Board 2276, no. 1: 9-16.
This paper presents and tests a method to design high-performance transit networks. The method produces conceptual plans for geometric idealizations of a particular city that are later adapted to the real conditions. These conceptual plans are generalizations of the hybrid network concept proposed in Daganzo (2010). The best plan for a specific application is chosen via optimization. The objective function is composed of analytic formulae for a concept‘s agency cost and user level of service. These formulae include as parameters key demand-side attributes of the city, assumed to be rectangular, and supply-side attributes of the transit technology. They also include as decision variables the system‘s line and stop spacings, the degree to which it focuses passenger trips on the city center, and the service headway. These decision variables are sufficient to define an idealized geometric layout of the system and an operating plan. This layout-operating plan is then used as a design target when developing the real, detailed master plan. Ultimately, the latter is simulated to obtain more accurate cost and level of service estimates. This process has been applied to design a high performance bus (HPB) network for Barcelona (Spain). The idealized solution for Barcelona includes 182 km of one-way infrastructure, uses 250 vehicles and costs 42,489 €/h to build and run. These figures only amount to about one third of the agency resources and cost currently used to provide bus service. A detailed design that resembles this target and conforms to the peculiarities of the city is also presented and simulated. The agency cost and user level of service metrics of the simulated system differ from those of the idealized model by less than 10%. Although the designed and simulated HPB systems provide sub-optimal spatial coverage because Barcelona lacks suitable streets, the level of service is good. Simulations suggest that if the proposed system was implemented side-by-side with the current one, it would capture most of the demand.
M. Estrada; M. Roca-Riu; H. Badia; F. Robusté; C.F. Daganzo. Design and Implementation of Efficient Transit Networks: Procedure, Case Study and Validity Test. Procedia - Social and Behavioral Sciences 2011, 17, 113 -135.
AMA StyleM. Estrada, M. Roca-Riu, H. Badia, F. Robusté, C.F. Daganzo. Design and Implementation of Efficient Transit Networks: Procedure, Case Study and Validity Test. Procedia - Social and Behavioral Sciences. 2011; 17 ():113-135.
Chicago/Turabian StyleM. Estrada; M. Roca-Riu; H. Badia; F. Robusté; C.F. Daganzo. 2011. "Design and Implementation of Efficient Transit Networks: Procedure, Case Study and Validity Test." Procedia - Social and Behavioral Sciences 17, no. : 113-135.
This paper presents and tests a method to design high-performance transit networks. The method produces conceptual plans for geometric idealizations of a particular city that are later adapted to the real conditions. These conceptual plans are generalizations of the hybrid network concept proposed in Daganzo (2010). The best plan for a specific application is chosen via optimization. The objective function is composed of analytic formulae for a concept’s agency cost and user level of service. These formulae include as parameters key demand-side attributes of the city, assumed to be rectangular, and supply-side attributes of the transit technology. They also include as decision variables the system’s line and stop spacings, the degree to which it focuses passenger trips on the city center, and the service headway. These decision variables are sufficient to define an idealized geometric layout of the system and an operating plan. This layout-operating plan is then used as a design target when developing the real, detailed master plan. Ultimately, the latter is simulated to obtain more accurate cost and level of service estimates. This process has been applied to design a high performance bus (HPB) network for Barcelona (Spain). The idealized solution for Barcelona includes 182 km of one-way infrastructure, uses 250 vehicles and costs 42,489 €/h to build and run. These figures only amount to about one third of the agency resources and cost currently used to provide bus service. A detailed design that resembles this target and conforms to the peculiarities of the city is also presented and simulated. The agency cost and user level of service metrics of the simulated system differ from those of the idealized model by less than 10%. Although the designed and simulated HPB systems provide sub-optimal spatial coverage because Barcelona lacks suitable streets, the level of service is good. Simulations suggest that if the proposed system was implemented side-by-side with the current one, it would capture most of the demand.
M. Estrada; M. Roca-Riu; H. Badia; F. Robusté; C.F. Daganzo. Design and implementation of efficient transit networks: Procedure, case study and validity test. Transportation Research Part A: Policy and Practice 2011, 45, 935 -950.
AMA StyleM. Estrada, M. Roca-Riu, H. Badia, F. Robusté, C.F. Daganzo. Design and implementation of efficient transit networks: Procedure, case study and validity test. Transportation Research Part A: Policy and Practice. 2011; 45 (9):935-950.
Chicago/Turabian StyleM. Estrada; M. Roca-Riu; H. Badia; F. Robusté; C.F. Daganzo. 2011. "Design and implementation of efficient transit networks: Procedure, case study and validity test." Transportation Research Part A: Policy and Practice 45, no. 9: 935-950.
Travel time for a road trip is a drivers’ most appreciated traffic information. Measuring travel times on a real time basis is also a perfect indicator of the level of service in a road link, and therefore is a useful measurement for traffic managers in order to improve traffic operations on the network. In conclusion, accurate travel time measurement is one of the key factors in traffic management systems. This paper presents a new approach for measuring travel times on closed toll highways using the existing surveillance infrastructure. In a closed toll system, where toll plazas are located on the on/off-ramps and each vehicle is charged a particular fee depending on its origin and destination, the data used for toll collection can also be valuable for measuring mainline travel times on the highway. The proposed method allows estimating mainline travel times on single sections of highway (defined as a section between two neighboring ramps) using itineraries covering different origin–destinations. The method provides trip time estimations without investing in any kind of infrastructure or technology. This overcomes some of the limitations of other methods, like the information delay and the excess in the travel time estimation due to the accumulation of exit times (i.e. the time required to travel along the exit link plus the time required to pay the fee at the toll gate). The results obtained in a pilot test on the AP-7 toll highway, near Barcelona in Spain, show that the developed methodology is sound.
Francesc Soriguera; D. Rosas; F. Robusté. Travel time measurement in closed toll highways. Transportation Research Part B: Methodological 2010, 44, 1242 -1267.
AMA StyleFrancesc Soriguera, D. Rosas, F. Robusté. Travel time measurement in closed toll highways. Transportation Research Part B: Methodological. 2010; 44 (10):1242-1267.
Chicago/Turabian StyleFrancesc Soriguera; D. Rosas; F. Robusté. 2010. "Travel time measurement in closed toll highways." Transportation Research Part B: Methodological 44, no. 10: 1242-1267.
In one of the very first papers on traffic flow theory back in 1952, Wardrop presented the difference between the space mean speed (SMS) and the time mean speed (TMS) of a group of traveling vehicles, and derived a relationship suitable for estimating TMS, given SMS and the speed variance over SMS. As time goes by, traffic practitioners have tended towards computing TMS instead of SMS, mainly when using double loop detectors, and nowadays this is the usual practice in traffic management centers. Therefore, the useful relationship between TMS and SMS should go the other way around in relation to Wardrop’s. Recently, the complementary relationship, suitable for estimating SMS from TMS and the speed variance over TMS, has been proved. However this is not enough, as speed variance is usually not available. The present paper develops a probabilistic method to estimate SMS from TMS without the previous knowledge of speed variance and only using the usual time aggregations of double loop detector data. The main assumption of the method – the normality of vehicle speed distribution – is discussed and a formulation to obtain the expected error of the estimation is derived. The results obtained with test data from the AP-7 highway, near Barcelona in Spain, show that the developed methodology is able to estimate SMS with an average relative error as low as 0.5%.
F. Soriguera; F. Robusté. Estimation of traffic stream space mean speed from time aggregations of double loop detector data. Transportation Research Part C: Emerging Technologies 2010, 19, 115 -129.
AMA StyleF. Soriguera, F. Robusté. Estimation of traffic stream space mean speed from time aggregations of double loop detector data. Transportation Research Part C: Emerging Technologies. 2010; 19 (1):115-129.
Chicago/Turabian StyleF. Soriguera; F. Robusté. 2010. "Estimation of traffic stream space mean speed from time aggregations of double loop detector data." Transportation Research Part C: Emerging Technologies 19, no. 1: 115-129.
A simulation optimization model is outlined: traffic signal offsets in intersections are calculated to minimize the travel time of bus users in an urban network. The model considers a passive signal priority system and restricts the maximal incremental delay caused to car users. The simulation tool is able to trace discrete trajectories of both buses and cars in a network. It also evaluates potential perturbations that may cause time variations for average performance. Moreover, the optimization tool is based on evolutionary algorithms. The results of applying the traffic signal coordination model to a set of small trial networks are given. It is proved that the algorithm is able to design a sequence of signal offsets that reduces bus travel times by an 8.5% rate in a real network while maintaining the incremental car delay below 5%.Postprint (published version
Miquel Estrada; C. Trapote; Mireia Roca Riu; F. Robusté. Improving Bus Travel Times with Passive Traffic Signal Coordination. Transportation Research Record: Journal of the Transportation Research Board 2009, 2111, 68 -75.
AMA StyleMiquel Estrada, C. Trapote, Mireia Roca Riu, F. Robusté. Improving Bus Travel Times with Passive Traffic Signal Coordination. Transportation Research Record: Journal of the Transportation Research Board. 2009; 2111 (1):68-75.
Chicago/Turabian StyleMiquel Estrada; C. Trapote; Mireia Roca Riu; F. Robusté. 2009. "Improving Bus Travel Times with Passive Traffic Signal Coordination." Transportation Research Record: Journal of the Transportation Research Board 2111, no. 1: 68-75.
Less-than-truckload (LTL) carriers supply freight transportation services for small parcel shipments. These companies consolidate multiple shipments in vehicles to guarantee the efficiency of the system. A method for LTL carriers is presented to solve the long-haul routing design problem with capacitated distribution centers and time-constrained shipments. The method uses direct, hub-and-spoke, and stopover strategies to allocate shipments in the set of routes. The resolution method is based on a tabu search algorithm. The search process in the solution domain is performed dynamically with four possible perturbations. The results obtained in a set of test problems demonstrate that the restart parameters play a significant role in the efficiency of the algorithm. Implementation of this computational technique in the long-haul operations network of the largest carrier in Spain reduced transportation costs by 6%.Postprint (published version
Miquel Estrada; Francesc Robusté. Long-Haul Shipment Optimization for Less-Than-Truckload Carriers. Transportation Research Record: Journal of the Transportation Research Board 2009, 2091, 12 -20.
AMA StyleMiquel Estrada, Francesc Robusté. Long-Haul Shipment Optimization for Less-Than-Truckload Carriers. Transportation Research Record: Journal of the Transportation Research Board. 2009; 2091 (1):12-20.
Chicago/Turabian StyleMiquel Estrada; Francesc Robusté. 2009. "Long-Haul Shipment Optimization for Less-Than-Truckload Carriers." Transportation Research Record: Journal of the Transportation Research Board 2091, no. 1: 12-20.
Francesc Robusté; Carlos F. Daganzo. Analysis of baggage sorting schemes for containerized aircraft. Transportation Research Part A: Policy and Practice 1992, 26, 75 -92.
AMA StyleFrancesc Robusté, Carlos F. Daganzo. Analysis of baggage sorting schemes for containerized aircraft. Transportation Research Part A: Policy and Practice. 1992; 26 (1):75-92.
Chicago/Turabian StyleFrancesc Robusté; Carlos F. Daganzo. 1992. "Analysis of baggage sorting schemes for containerized aircraft." Transportation Research Part A: Policy and Practice 26, no. 1: 75-92.
This paper shows how the geometric concepts examined in the first paper perform for baggage operations, recognizing that passengers and bags travel different distances through the airport. The paper shows that the most effective geometry (minimizing total passenger walking plus baggage travel costs) can be selected by focusing on passenger walking alone, provided that one first calculates an equivalent percentage of transfers with a simple formula. The paper also introduces a “sun” terminal concept, consisting of a circular concourse (open or closed) with both gates and piers (possibly with branches), which generalizes the geometries of part one to some advantage. Finally, the paper introduces and compares the results of two techniques that are useful for more refined analyses. The first of these, calculus of variations, was used to develop simple approximate formulas for the optimal shape of parallel‐pier terminals. The second technique, simulated annealing, does not lead to formulas but can be used without simplifications; e.g., to refine a preliminary design with the aid of a computer, recognizing real‐world complications.
Francesc Robusté; Carlos F. Daganzo. Centralized Hub‐Terminal Geometric Concepts. II: Baggage and Extensions. Journal of Transportation Engineering 1991, 117, 159 -177.
AMA StyleFrancesc Robusté, Carlos F. Daganzo. Centralized Hub‐Terminal Geometric Concepts. II: Baggage and Extensions. Journal of Transportation Engineering. 1991; 117 (2):159-177.
Chicago/Turabian StyleFrancesc Robusté; Carlos F. Daganzo. 1991. "Centralized Hub‐Terminal Geometric Concepts. II: Baggage and Extensions." Journal of Transportation Engineering 117, no. 2: 159-177.