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on Transport Economics |
| By: | Guensler, Randall; Liu, Haobing; Lu, Hongyu; Chang, Chia-Huai "Chris"; Dai, Ziyi; Xia, Tian; Fu, Zixiu; Liu, Diyi; Kim, Daejin; Zhao, Yingping; Guin, Angshuman |
| Abstract: | Ongoing assessment of system performance monitoring is critical to successful and efficient transportation planning, ensuring that infrastructure investments provide a desired return on investment. As with any new transportation facility, it is important to understand how Express Lane facilities affect travel behavior, resulting on-road vehicle activity, and subsequent person-throughput (a function of vehicle occupancy) as part of the facility performance assessment. This report summarizes the vehicle and person throughput analysis for the I-75 Northwest Corridor (NWC) and I-85 Express Lanes in Atlanta, GA, undertaken by the Georgia Institute of Technology research team for the State Road and Tollway Authority (SRTA). The research team tracked changes in observed vehicle throughput on four managed lane corridors and collected vehicle occupancy (persons per vehicle) data to assess changes in both vehicle throughput and person throughput associated with the opening of new Express Lane facilities. The team collected traffic volumes by video observation (GDOT’s Georgia NaviGAtor machine vision system and SRTA’s vehicle activity monitoring system). The team implemented a large-scale data collection effort for vehicle occupancy across all general purpose freeway lanes and from SRTA’s Express Lanes over a two-year period (before-and-after the opening of the Express Lanes). Between the baseline year (2018) and post-opening year (2019), the team observed a decrease in average vehicle occupancy (persons/vehicle), coupled with a significant increase in traffic volumes, especially on the NWC. The combined effect of increased traffic volumes and decreased occupancy still led to an overall increase in person throughput at all sites. Vehicle throughput on the I-85 corridor increased by about 5-7% and person throughput increased by 1-2% in the morning peak, and increased by around 10% for vehicles and 5% for persons in the evening peak. Vehicle throughput increased by more than 35% on I-575 in the AM and PM peaks, and by the same on I-75 in the AM peaks (only minor increases were noted in the PM peaks), likely due to the diversion of commute traffic from arterials onto the freeway corridor once the Express Lanes opened and congestion declined. Based upon vehicle throughput and occupancy distributions, the largest share of the increase in vehicle throughput in the peak periods came from an influx of single-occupant vehicle activity onto the corridor. Even though the number of carpools traversing the I-575 corridor increased slightly during the morning peak, the overall carpool mode share (percentage of carpools) decreased after the significantly greater numbers of single-occupant vehicles began using the corridor. View the NCST Project Webpage |
| Keywords: | Engineering, Carpools, Demographics, Evaluation and assessment, Express lanes, Focus groups, High occupancy toll lanes, Reversible traffic lanes, Surveys, Through traffic, Vehicle occupancy |
| Date: | 2022–06–01 |
| URL: | http://d.repec.org/n?u=RePEc:cdl:itsdav:qt47v759fs&r= |
| By: | LIAN, Ying; LUCAS, Flavien; SÖRENSEN, Kenneth |
| Abstract: | We propose to solve a real-time traffic variation of the On-Demand Bus Routing Problem (ODBRP) introduced by Melis and Sörensen (2021). The ODBRP belongs to the category of dial-a-ride problems (DARP), and features departure and arrival bus station selection. This problem is specifically aimed at planning a fleet of on-demand buses in an urban environment. However, cities are frequently plagued by traffic congestion, which may cause delays and missed time windows for passengers. To deal with this situation, we introduce, study, and solve a variant of the ODBRP in which travel times are both time-dependent (i.e., the travel time between two nodes depends on the departure time) and updated dynamically. In our approach, congested roads that might cause passenger delays are modeled by frequently updating the travel speed on the road segments that constitute them. The resulting problem is solved by using a K-shortest paths procedure to determine alternative paths between bus stations combined with a variable neighborhood search procedure to repair violated time windows. Our experimental results show the overall effectiveness of this real-time control under different degrees of flexibility (congestion and number of buses available). Specifically, the average tardiness, maximum tardiness, and number of late passengers are significantly reduced under a wide range of congestion scenarios, from slight to severe. In addition, this effectiveness holds for various ratios of requests to the number of vehicles. |
| Keywords: | On-demand bus, Real-time traffic information, Dynamic travel speed, Real-time control |
| Date: | 2022–05 |
| URL: | http://d.repec.org/n?u=RePEc:ant:wpaper:2022003&r= |
| By: | LIAN, Ying; LUCAS, Flavien; SÖRENSEN, Kenneth |
| Abstract: | Electric vehicle routing problems (EVRPs) with recharging policy consider the limited range of electric vehicles and thus include intermediate visits to charging stations (CSs). In general, minimizing the resultant charging costs such as charging duration or charging amount are also part of the objective of EVRP. Accordingly, EVRPs have received considerable attention over the past years. Nevertheless, this type of problems in the domain of passenger transportation, a VRP variant, has been rarely studied in the literature, especially with time windows, a realistic nonlinear charging function or partial charging policy. Hence this research extends the existing work on EVRP to an On-Demand Bus Routing Problem (ODBRP) which transports passengers with bus station assignment (BSA). The resultant problem is the EODBRP. Specifically, each passenger can have more than one stations to board or alight, and they are assigned to the ones with the smallest increase in the total user ride time (URT). In EODBRP, frequent intermediate visits to CSs are considered. Moreover, nonlinear charging functions are in use and partial charging strategy is applied. To solve the EODBRP, a greedy insertion method with ‘charging first, routing second’ strategy is developed, followed by a large neighborhood search (LNS) which consists of local search (LS) operators to further improve the solution quality. Experimental data were generated by a realistic instance generator based on a real city map, and the corresponding results show that the proposed heuristic algorithm performs well in solving the EODBRP. Finally, sensitivity analyses with divergent parameters such as the temporal distributions of passengers and bus ranges may provide practical guidance |
| Keywords: | On-demand bus routing problem, Electric vehicle, Non-linear charging function, Partial charging |
| Date: | 2022–05 |
| URL: | http://d.repec.org/n?u=RePEc:ant:wpaper:2022005&r= |
| By: | Lijing Zhu (China University of Petroleum); Jingzhou Wang (China University of Petroleum, IFPEN - IFP Energies nouvelles - IFPEN - IFP Energies nouvelles, IFP School); Arash Farnoosh (IFPEN - IFP Energies nouvelles - IFPEN - IFP Energies nouvelles, IFP School); Xunzhang Pan (China University of Petroleum) |
| Abstract: | To reduce traffic congestion and protect the environment, license plate control (LPC) policy has been implemented in Beijing since 2011. In 2019, 100,000 vehicle license plates were distributed, including 60,000 for electric vehicles (EVs) and 40,000 for gasoline vehicle (GVs). However, whether the current license plate allocation is optimal from a social welfare maximization perspective remains unclear. This paper proposes a two-level Stackelberg game, which portrays the interaction between vehicle applicants and the government to quantify the optimal number of EV license plates under the LPC policy in Beijing. The equilibrium number of EV license plates derived from the Stackelberg model is 58,800, which could increase the social welfare by 0.38%. Sensitivity analysis is conducted to illustrate the impact of important influential factors — total license plate quota, vehicle rental fee, and energy price — on EV adoption. The LPC policy under COVID-19 is also studied through a scenario analysis. If the government additionally increases the total quota by 20,000, 24% could be allocated to GV and 76% to EV. One third reduction of the current vehicle rental fee could increase EV license plates by 10.5%. In terms of energy prices, when gasoline price is low, reducing electricity prices could contribute to EV adoption significantly, while that effect tapers off as gasoline prices increase. |
| Keywords: | Electric vehicle,License plate control (LPC) policy,Stackelberg game theory,License plate quota |
| Date: | 2022–04 |
| URL: | http://d.repec.org/n?u=RePEc:hal:journl:hal-03686100&r= |
| By: | Ismir Mulalic (Copenhagen Business School); Jan Rouwendal (Vrije Universiteit Amsterdam) |
| Abstract: | This paper considers the impact of the introduction of a metro network in the Copenhagen metropolitan area. Using travel surveys from years before and after the opening of the metro network, we observe a significant change in travel times, speeds and mode choice for commutes that can completely or partly be realized by the metro. Interest in the metro among the higher educated is much stronger than among the lower educated. House prices in the vicinity of the metro stations increased significantly. The total additional value of real estate generated by the metro is appr. 40% of the actual construction cost. The government captured a substantial part of the value generated by the metro by concentrating housing construction in some hitherto undeveloped areas close to metro stations. We use a gravity model to explore the implications of the metro for urban structure in an urban equilibrium context and find that all adjustment takes place in the housing market. The lower and medium educated face adjustments in housing attractiveness that counteract the initial impact of the metro. We find no evidence for such adverse effects on the higher educated, which suggest a close connection between the impact of the metro and gentrification in the Copenhagen. |
| Keywords: | underground transportation, urban structure, public transport investment, commuting, gentrification |
| JEL: | D1 R4 R1 |
| Date: | 2022–05–31 |
| URL: | http://d.repec.org/n?u=RePEc:tin:wpaper:20220035&r= |
| By: | Gilbert E. Metcalf |
| Abstract: | More stringent fuel economy standards and increased market penetration of electric vehicles (EVs) present challenges to federal policy makers who historically have relied on motor vehicle fuel excise taxes to fund highway projects. This paper considers the distributional implications of a federal tax swap where a new vehicle miles travelled (VMT) tax is used to finance a reduction in the federal excise tax on gasoline. Whether the tax shift is progressive (relative to the pivot point) or not depends on the sign of the income elasticity of demand for fuel intensity. If it is negative (higher-income households demand more fuel efficient cars), then the tax shift is progressive around the pivot point. Conversely, if it is positive, then the tax shift is regressive around the pivot point. Where the pivot point occurs and how progressive a shift occurs is an empirical matter. Using data from the 2017 National Household Travel Survey (NHTS), I find that the income elasticity of fuel intensity is negative and that this revenue-neutral tax swap to be mildly progressive for all household incomes below $200,000. This is driven, in part, by the fact that higher income households are more likely to drive hybrid and electric vehicles and to own newer vehicles which, due to increasingly stringent fuel economy standards, tend to be more fuel efficient. How the progressivity of a tax swap changes as fuel economy standards are raised and EV market penetration increases depends on who purchases EVs and more efficient vehicles. Federal policy will likely play a role in influencing the future distribution of EV ownership. In addition, I find the tax swap benefits rural drivers and has no appreciable differential impacts on Black and Hispanic households. |
| JEL: | H22 H23 Q48 R48 |
| Date: | 2022–06 |
| URL: | http://d.repec.org/n?u=RePEc:nbr:nberwo:30129&r= |
| By: | Allister Loder; Fabienne Cantner; Lennart Adenaw; Markus Siewert; Sebastian Goerg; Markus Lienkamp; Klaus Bogenberger |
| Abstract: | In spring 2022, the German federal government agreed on a set of measures that aim at reducing households' financial burden resulting from a recent price increase, especially in energy and mobility. These measures include among others, a nation-wide public transport ticket for 9 EUR per month and a fuel tax cut that reduces fuel prices by more than 15% . In transportation research this is an almost unprecedented behavioral experiment. It allows to study not only behavioral responses in mode choice and induced demand but also to assess the effectiveness of transport policy instruments. We observe this natural experiment with a three-wave survey and an app-based travel diary on a sample of hundreds of participants as well as an analysis of traffic counts. In this first report, we inform about the study design, recruiting and initial participation of study participants. |
| Date: | 2022–06 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:2206.00396&r= |
| By: | Friedrich, Christian |
| Abstract: | Urban freight transport is an indispensable component of economic and social life in cities. Compared to other types of transport, however, it contributes disproportionately to the negative impacts of traffic. As a result, urban freight transport is closely linked to social, environmental, and economic challenges. Managing urban freight transport and addressing these issues poses challenges not only for local city administrations but also for companies, such as logistics service providers (LSPs). Numerous policy measures and company-driven initiatives exist in the area of urban freight transport to overcome these challenges. One central approach is the consolidation of urban freight transport. This dissertation focuses on urban consolidation centers (UCCs) which are a widely studied and applied measure in urban freight transport. The fundamental idea of UCCs is to consolidate freight transport across companies in logistics facilities close to an urban area in order to increase the efficiency of vehicles delivering goods within the urban area. Although the concept has been researched and tested for several decades and it was shown that it can reduce the negative externalities of freight transport in cities, in practice many UCCs struggle with a lack of business participation and financial difficulties. This dissertation is primarily focused on the costs and savings associated with the use of UCCs from the perspective of LSPs. The cost-effectiveness of UCC use, which is also referred to as cost attractiveness, can be seen as a crucial condition for LSPs to be interested in using UCC systems. The overall objective of this dissertation is two-fold. First, it aims to develop models to provide decision support for evaluating the cost-effectiveness of using UCCs. Second, it aims to analyze the impacts of urban freight transport regulations and operational characteristics on the cost attractiveness of using UCCs from the perspective of LSPs. In this context, a distinction is made between UCCs that are jointly operated by a group of LSPs and UCCs that are operated by third parties who offer their urban transport service for a fee. The main body of this dissertation is based on three research papers. The first paper focuses on jointly-operated UCCs that are operated by a group of cooperating LSPs. It presents a simulation model to analyze the financial impacts on LSPs participating in such a scheme. In doing so, a particular focus is placed on urban freight transport regulations. A case study is used to analyze the operation of a jointly-operated UCC for scenarios involving three freight transport regulations. The second and third papers take on a different perspective on UCCs by focusing on third-party operated UCCs. In contrast to the first paper, the second and third papers present an evaluation approach in which the decision to use UCCs is integrated with the vehicle route planning of LSPs. In addition to addressing the basic version of this integrated routing problem, known as the vehicle routing problem with transshipment facilities (VRPTF), the second paper presents problem extensions that incorporate time windows, fleet size and mix decisions, and refined objective functions. To heuristically solve the basic problem and the new problem variants, an adaptive large neighborhood search (ALNS) heuristic with embedded local search heuristic and set partitioning problem (SPP) is presented. Furthermore, various factors influencing the cost attractiveness of UCCs, including time windows and usage fees, are analyzed using a real-world case study. The third paper extends the work of the second paper and incorporates daily and entrance-based city toll schemes and enables multi-trip routing. A mixed-integer linear programming (MILP) formulation of the resulting problem is proposed, as well as an ALNS solution heuristic. Moreover, a real-world case study with three European cities is used to analyze the impact of the two city toll systems in different operational contexts. |
| Date: | 2022 |
| URL: | http://d.repec.org/n?u=RePEc:dar:wpaper:132875&r= |
| By: | Shaheen, Susan; Farrar, Emily |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2022–01–01 |
| URL: | http://d.repec.org/n?u=RePEc:cdl:itsrrp:qt0gz5t8sw&r= |
| By: | Minh Hieu Nguyen (AME-DEST - Dynamiques Economiques et Sociales des Transports - Université Gustave Eiffel); Jimmy Armoogum (AME-DEST - Dynamiques Economiques et Sociales des Transports - Université Gustave Eiffel); Cedric Garcia (AME-DEST - Dynamiques Economiques et Sociales des Transports - Université Gustave Eiffel) |
| Abstract: | Mode detection is the heart of researches based on GPS data collected in mobility surveys using wearable devices and recently smartphones. There is room in the literature of this field that is the great focus on developed countries like US, Sweden, Switzerland, Canada, Australia and so on, which has led list of modes to be around basic modes including walk, bike, bus/tram, car and train. Here, we presented an attempt to identify modes from data in a developing country where mobility heavily depends upon motorcycle. Data: Between mid-April and mid-May in 2019, the lab DEST under IFSTTAR (France) carried out a survey using the app TRavelVU developed by Trivector (Sweden) to collect both GPS data at high frequency ranging from 1 to 3 seconds and the corresponding ground truth of 63 participants in Hanoi, Vietnam. Among 2791 segments, 758 (27.2%), 104 (3.7%), 97 (3.5%), 1245 (44.6%) and 587 (21%) are walking, biking, bus, motor and car, respectively. Method: To distinguish five modes, deterministic and random forest methods were created and described in the following table. Method Description RULE-BASED 95th percentile speed Median speed Proximity to bus stops Mode Step 1 < 3.5 < 2.0 - Walk Step 2 < 6.0 < 4.0 - Bike Step 3 < 15.0 > 3.5 Yes Bus Step 4 > 12.0 > 6.0 - Car Step 5 The remainder of segments Motor - This is a hierarchical process where segments given labels in a previous step are not considered in the subsequent. - Proximity to bus stops refers to the distances from both origin and destination of a segment to the nearest stops within 75 m RANDOM FOREST Features: 95th percentile speed, median speed, proximity to bus stops (0 if no and 1 if yes), heading change rate, low speed rate, 95 percentile acceleration, average (absolute) acceleration. Splitting data: at the rate of 75% vs. 25% Results and discussions: The prediction results of two methods were compared with the ground truth and showed on the normalised confusion matrixes in the following figure. Random forest generated higher accuracy (79.08%) than Rule-based (61.73%) thanks to detecting significantly more correctly walk and motorcycle that make up the largest percentages in the mode share; however, it identified obviously worse bus, bike and car. The reason is that random forest over-fitted seriously motorcycle and walks. This problem came from the nature of unbalanced mode usage and limited sample size of secondary modes (i.e. bike and bus). As for the rule-based approach, compared with random forest, it showed a considerable higher recalls of bus and bike. Rules failed to address overlapping of speed between modes but it demonstrated the advantage of a hierarchical process over random forest where all modes and features were examined simultaneously. To illustrate, bus was detected far better (53% vs. 11%) if only considered proximity to bus stops and speed profiles than considered adjacent to bus stops with a series of other features such as heading change rate, acceleration characteristics, distance and so on. Among five modes, motorcycle was the major source of misclassification. It could show similar behaviours to car, bus and bike. Whereas, detecting bus by origin and destination of each segment seems to be insufficient. Conclusion: Inferring modes from GPS data in emerging countries is demanding due to the inclusion of motorcycle as the main means. A hierarchical process would be better choice in case of the limited sample size of some modes. Together with the first and the last point, the association between GPS points between them and GIS data should be examined to gain higher precision level for bus classification. This paper contributes to the geographical diversity of the mode detection field. Besides, it is one of the first studies covering motorcycle in the list of classification. |
| Keywords: | MODE DETECTION,MOBILITY SURVEY,MOTORCYCLE,SMARTPHONE,GPS |
| Date: | 2022–03–20 |
| URL: | http://d.repec.org/n?u=RePEc:hal:journl:hal-03670773&r= |
| By: | Cobos, Carlos; Escribano, Álvaro |
| Abstract: | The research is focused on the impact of High-Speed Rail (HSR) by Municipalities on population density and unemployment, based on economic and demographic variables of Spain. For that purpose, we construct a panel for a 15-years period (1998-2012) where the treatment variable HSR takes the value of 1 when the municipality is within an area of 10 km from the train station, allowing for the size of the municipality to interact with HSR. Two different samples are considered: all the municipalities and by HSR corridors.To evaluate the transport service impact, a Difference in Difference technique is applied to different model specifications to isolate the HSR effects, after controlling for relevant variables. A simultaneous equation panel data model is estimated, equation by equation by ordinary least squares and by dynamic ordinary least squares, with robust empirical results. Reallocation effects on the population are observed in the national sample, with positive effects on small cities and little municipalities (20,000 people). Only the South and North corridors show positive net results on population density. With respect to unemployment, the effects are not so clear. At the national level, only small municipalities ( |
| Keywords: | High-Speed Rail; Municipalities; Radial Infrastructure Network; Depopulation; Unemployment; Reallocation Effects By Corridors |
| JEL: | R1 R12 R14 R23 R41 R58 |
| Date: | 2022–06–24 |
| URL: | http://d.repec.org/n?u=RePEc:cte:werepe:35284&r= |
| By: | Bolivar, Osmar |
| Abstract: | The research aims to evaluate the impact of paved major roads on economic growth at the municipal level in Bolivia, Paraguay and Ecuador. Due to the absence of municipal information, pub-licly available satellite data are used to construct a municipal panel dataset on a yearly basis from 2000 to 2013; particularly, nightlight luminosity is adopted as a proxy for economic activity. Methodologically, empirical evidence is obtained regarding the effect of having access to a paved major road on luminosity, as well as the elasticity between GDP and nightlight luminosity; both estimates are then linked to approximate economic growth in benefited municipalities. The findings suggest that, on aver-age, economic activity was 0.5% to 0.6% higher in municipalities that benefited from paved major roads than in municipalities that did not. The effects vary over time and are dependent on whether the benefited areas are located closer to the road or are part of a population center. |
| Keywords: | Desarrollo urbano, Economía, Evaluación de impacto, Infraestructura, Investigación socioeconómica, Movilidad urbana, Movilidad urbana, Seguridad vial, Vialidad, |
| Date: | 2022 |
| URL: | http://d.repec.org/n?u=RePEc:dbl:dblwop:1910&r= |
| By: | Warnes, Pablo Ernesto |
| Abstract: | How do improvements in the urban transport infrastructure affect the spatial sorting of residents with different levels of in-come and education within a city? What are the welfare effects of improving urban transit once we take into account these pat-terns of spatial sorting? In this paper, I study the effects of the construction of a bus rapid transit system (BRT) on the spatial reorganization of residents within the city of Buenos Aires, Ar-gentina. To do so, I leverage an individual level panel data set of more than two million residents with which I can describe intra-city migration patterns. I first find reduced form evidence that the construction of the BRT increased the spatial segregation between high and low-skilled residents within the city. I then develop a dynamic quantitative spatial equilibrium model of a city with heterogeneous workers that allows me to quantify the welfare effects of this BRT system while taking into account these spatial sorting patterns. With this quantitative framework, I can measure the average welfare gains for residents that were living near the BRT lines before these were built. |
| Keywords: | Ciudades, Desarrollo urbano, Evaluación de impacto, Infraestructura, Investigación socioeconómica, Movilidad urbana, Servicios públicos, Transporte, |
| Date: | 2022 |
| URL: | http://d.repec.org/n?u=RePEc:dbl:dblwop:1911&r= |
| By: | Mayara Moraes Monteiro; Carlos M. Lima Azevedo; Maria Kamargianni; Yoram Shiftan; Ayelet Gal-Tzur; Sharon Shoshany Tavory; Constantinos Antoniou; Guido Cantelmo |
| Abstract: | Car-sharing services have been providing short-term car access to their users, contributing to sustainable urban mobility and generating positive societal and often environmental impacts. As car-sharing business models vary, it is important to understand what features drive the attraction and retention of its members in different contexts. For that, it is essential to examine individuals preferences for subscriptions to different business models and what they perceive as most relevant, as well as understand what could be attractive incentives. This study aims precisely to examine individuals preferences for the subscription of different car-sharing services in different cities. We designed a stated preference experiment and collected data from three different urban car-sharing settings, namely Copenhagen, Munich, and Tel Aviv-Yafo. Then a mixed logit model was estimated to uncover car-sharing plan subscription and incentives preferences. The results improve our understanding of how both the features of the car-sharing business model and the provision of incentives can maintain and attract members to the system. The achieved insights pave the road for the actual design of car-sharing business models and incentives that can be offered by existing and future car-sharing companies in the studied or similar cities. |
| Date: | 2022–06 |
| URL: | http://d.repec.org/n?u=RePEc:arx:papers:2206.02448&r= |
| By: | Bai, Yihang; Cao, Mengqiu; Wang, Ruoyu; Liu, Yuqi; Wang, Seunghyeon |
| Abstract: | Introduction: Active travel is currently gaining popularity worldwide as a sustainable form of travel. However, very few studies have examined how the built environment affects active travel behaviour on university campuses, particularly in China. It is a key feature of Chinese university campuses that they are generally gated communities, which are spatially organised in a very different way from campuses in other countries, and they often also provide for students’ daily needs, meaning that students tend to travel off-campus less frequently. Aims: This research aims to explore the link between street greenery and the active travel behaviour of students on closed university campuses in China. Methods: The study combined sensor data from Guangzhou Higher Education Mega Centre (HEMC), China, with individual cross-sectional survey data from university students and applied a multilevel logistic regression model to conduct the analysis. Street-view images were analysed using a deep learning approach, which represents an emerging method for assessing urban green space. Results: The results demonstrated that street greenery on campuses is positively associated with active travel among university students. Modes of travel also influenced active travel, with university students who owned bicycles tending to participate in active travel more; however, those who travelled by electric bikes were less likely to participate in active travel. Conclusions: This study suggests that policymakers and transport planners should focus more on greening urban areas and improving walking and cycling environments to achieve green transport goals through urban planning. |
| Keywords: | active travel; health; equity; behavioural change; street greenery; urban planning |
| JEL: | C1 |
| Date: | 2022–05–27 |
| URL: | http://d.repec.org/n?u=RePEc:ehl:lserod:115239&r= |
| By: | LIAN, Ying; LUCAS, Flavien; SÖRENSEN, Kenneth |
| Abstract: | The On-Demand Bus Routing Problem (ODBRP) is defined as a large-scale dial-a-ride problem with bus station assignment. Specifically, each passenger can have alternative stations to board and alight; then, station pairs with the smallest total User Ride Time (URT) are chosen for overall efficiency. In the dynamic ODBRP (DODBRP), buses are only dispatched to the stations with known requests. However, this paper considers prepositioning: buses are sent to stations where new requests are likely to appear if the expected number of served requests has increased consequently. A heuristic algorithm with variable neighborhood search (VNS) is proposed to solve this dynamic and stochastic ODBRP, with multiple scenarios representing different realizations of stochastic requests. Experimental data show the superiority of prepositioning compared to DODBRP. On average, 24.27% - 38.80% more passengers can be served with the use of prepositioning with a simultaneous reduction from 2.06% to 5.93% of the average URT. In addition, different parameters are investigated to test robustness, such as instance sizes, station distributions, ratios of dynamic requests, probabilities of stochastic requests, time windows, and levels of estimation accuracy of stochastic requests. |
| Keywords: | Routing, Stochastic requests, Dynamic requests, Multiple scenarios, Prepositioning |
| Date: | 2022–05 |
| URL: | http://d.repec.org/n?u=RePEc:ant:wpaper:2022004&r= |
| By: | Ilse Rubbrecht (National Bank of Belgium) |
| Abstract: | In 2020, Belgian ports generated € 31.8 billion in direct and indirect value added (7% of Belgian GDP) and employed 254 611 full-time equivalents (FTEs) either directly or indirectly (5.9% of Belgian domestic employment including the self-employed). Despite the COVID-19 outbreak, direct employment at Belgian ports remained quite stable in 2020. The temporary lay-off system - more flexible during the pandemic - played a vital role in avoiding redundancies. Job losses in the port population were especially visible in the non-maritime cluster because the maritime activities were considered as essential and allowed to operate continuously. Direct value added at Belgian ports fell by 1.2% in 2020 against a drop of 4% for the whole of the Belgian economy. The drop was particularly visible in the non-maritime cluster more precisely in those branches hit by the temporary imposed closure of businesses or impacted by demand contractions and supplychain disruptions. In 2020, direct investment by all Belgian ports taken together rose by 5.1% to € 5.1 billion, thanks to higher sums invested in the chemicals industry and the cargo-handling sector. Analysing the investment degree levels by branch of activity, results indicate that shipping companies and port authorities invested relatively more given the competitive businesses in which they operate. A relatively high degree of investment is also notified for the energy sector and the industrial branches, whose operational activity is largely based on high technological knowledge and whose business is substantially subject to future developments. During the pandemic, total turnover figures fell. Downscaling costs to the same extend as declining sales was difficult given the presence of fixed costs, accordingly the profitability level of a median port company declined slowly. However, while strong performing1 port companies in terms of operating profit suffered a drop in profitability, weak performing businesses enhanced theirs owing to the generous government support measures. (In)direct support to wage and (para)fiscal payments endorsed port companies to maintain or even slightly strengthen their liquidity position, while their solvency was sustained as well. |
| Keywords: | : Belgian ports, microeconomic data, direct effects, indirect effects, input-output table, employment, value added, investment |
| JEL: | C13 C43 C67 C81 J21 J49 L91 L92 R11 R15 R41 |
| Date: | 2022–05 |
| URL: | http://d.repec.org/n?u=RePEc:nbb:reswpp:202205-407&r= |
| By: | Nguyen-Tien, Viet; Dai, Qiang; Harper, Gavin D.j.; Anderson, Paul A.; Elliott, Robert J.R. |
| Keywords: | lithium-ion-batteries; electric vehicles; circular economy; recycle; life cycle assessment; supply chain; material flow analysis; transitions; transition management |
| JEL: | R14 J01 |
| Date: | 2022–05–30 |
| URL: | http://d.repec.org/n?u=RePEc:ehl:lserod:115263&r= |