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Abate, Megersa
Publications (8 of 8) Show all publications
Abate, M., Vierth, I., Karlsson, R., de Jong, G. & Baak, J. (2018). A disaggregate stochastic freight transport model for Sweden. Transportation, 1-26
Open this publication in new window or tab >>A disaggregate stochastic freight transport model for Sweden
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2018 (English)In: Transportation, ISSN 0049-4488, E-ISSN 1572-9435, p. 1-26Article in journal (Refereed) In press
Abstract [en]

This paper presents estimation results for models of transport chain and shipment size choice, as well as an implementation of the estimated disaggregate models (for two commodity groups), in the context of the national freight transport model for Sweden. The new model is a disaggregate and stochastic (logit) model, whereas the existing Swedish national model is deterministic. One advantage of the new approach is that it bases the underlying behavior of shippers on a stronger empirical foundation (that is micro-data from the Swedish Commodity Flow Survey, CFS). Another advantage is that it overcomes a well-known disadvantage of deterministic models that lead to implausibly large responses to changes in scenario or policy variables. Although estimation and implementation of aggregate stochastic models were done before, in the context of a national freight transport forecasting model, we think this is the first implementation of disaggregate freight transport chain and shipment size models estimated on choice data for individual shipments, certainly in Europe. We carried out a number of model runs with both versions of the implemented model to compare elasticities and found that transport cost and time elasticities for tonne-km are smaller (in absolute values) in the disaggregate stochastic model than in their deterministic counterparts.

Place, publisher, year, edition, pages
Springer New York LLC, 2018
Keywords
Freight transport, Freight, Size, Mathematical model, Stochastic, Transport operator, Behaviour, Cost, Time, Elasticity
National Category
Transport Systems and Logistics
Research subject
10 Road: Transport, society, policy and planning, 12 Road: Freight transport
Identifiers
urn:nbn:se:vti:diva-13537 (URN)10.1007/s11116-018-9856-9 (DOI)2-s2.0-85040766219 (Scopus ID)
Available from: 2019-01-31 Created: 2019-01-31 Last updated: 2019-03-15Bibliographically approved
Abate, M. (2016). Economic effects of air transport market liberalization in Africa. Transportation Research Part A: Policy and Practice, 92, 326-337
Open this publication in new window or tab >>Economic effects of air transport market liberalization in Africa
2016 (English)In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 92, p. 326-337Article in journal (Refereed) Published
Abstract [en]

Although the aviation industry is increasingly becoming important for Africa's economic development and integration, the ability of airlines to access foreign markets remains hindered by restrictive regulatory policies. Attempts have been made to fully liberalize the intra-African air transport market. Except for general assertions about the merits/demerits of liberalization, our empirical understanding of the welfare effects of such polices in Africa remains rudimentary. This study empirically measures the economic effects of air transport liberalization, mainly on two supply side variables: fare and service quality, measured as departure frequency. The empirical models evaluate how air fares and departure frequency respond to measures of openness in air services agreements, while controlling for other determinants. The results show up to 40% increase in departure frequency in routes that experienced some type of liberalization compared to those governed by restrictive bilateral air service agreements. Furthermore, there is a relatively larger increase in departure frequency in routes which experienced partial liberalization compared to fully liberalized ones. This can be explained by the diminishing marginal effect of progressive liberalization on departure frequency. While the effect of liberalization is substantial in improving service quality, there is no evidence of its fare reducing effect.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Air transport, Economics, Deregulation (market), Africa, Impact study, Tariff, Frequency
National Category
Economics
Research subject
SAB, Prd Aircrafts, air transport and airports
Identifiers
urn:nbn:se:vti:diva-10809 (URN)10.1016/j.tra.2016.06.014 (DOI)000384381700025 ()2-s2.0-84979675849 (Scopus ID)
Available from: 2016-08-11 Created: 2016-08-09 Last updated: 2017-04-21Bibliographically approved
Abate, M. (2014). Determinants of Capacity Utilisation in Road Freight Transportation. Journal of Transport Economics and Policy, 48, 137-152
Open this publication in new window or tab >>Determinants of Capacity Utilisation in Road Freight Transportation
2014 (English)In: Journal of Transport Economics and Policy, ISSN 0022-5258, E-ISSN 1754-5951, Vol. 48, p. 137-152Article in journal (Refereed) Published
Abstract [en]

Recent performance indicators in the European road freight transport sector show there is an excess capacity. To shed light on this, this paper studies two aspects of capacity utilisation in trucking: the extent of empty running and the load factor. Using a joint econometric modelling framework, the paper shows that they can be explained as a function of haul, carrier, and truck characteristics. For estimation, a unique dataset from the Danish heavy vehicle trip diary was used. The results indicate distance and being a for-hire carrier have a positive effect on capacity utilisation, whereas the effect of truck size is non-linear.

Keywords
Freight transport, Logistics, Load, Characteristics, Distance, Freight, Operator, Lorry
National Category
Transport Systems and Logistics
Research subject
10 Road: Transport, society, policy and planning, 12 Road: Freight transport
Identifiers
urn:nbn:se:vti:diva-10090 (URN)000339931400009 ()2-s2.0-84890914684 (Scopus ID)
Available from: 2016-03-08 Created: 2016-03-02 Last updated: 2017-11-30Bibliographically approved
Abate, M. (2014). Does fuel price affect trucking industry’s network characteristics?: evidence from Denmark. Stockholm: Centre for Transport Studies
Open this publication in new window or tab >>Does fuel price affect trucking industry’s network characteristics?: evidence from Denmark
2014 (English)Report (Other academic)
Abstract [en]

 The 2000s were dominated by rising fuel prices and economic recession. Both had an impact on the structure of the trucking industry and how freight was moved. This paper examines how fuel prices shaped trucking industry’s network characteristics such as the average length of haul, average load, and capacity utilization. In particular, we show the effect of fuel price on average length of haul using 29 quarterly independent surveys from the Danish heavy goods vehicle (HGV) trip diary from 2004 to 2011. The results show that the average length of haul is sensitive to changes in fuel price: a DKK 1 (0.18$) increase in diesel price/liter leads to a 4 percent decrease in the average length of haul in the 2004-2007 period. This implies that firms improve transport efficiency by reducing the number of kilometers needed to transport a tonne of cargo as a short run response to fuel price increases. This result, however, is not confirmed for the years following the 2008 financial crisis. It also depends on where in the distribution of the average length of haul one looks.

Place, publisher, year, edition, pages
Stockholm: Centre for Transport Studies, 2014. p. 34
Series
CTS Working Paper ; 2014:26
Keywords
Does fuel price affect trucking
National Category
Economics
Research subject
00 Road: General works, surveys, comprehensive works, 02 Road: Economics
Identifiers
urn:nbn:se:vti:diva-7447 (URN)
Available from: 2014-12-12 Created: 2014-12-12 Last updated: 2016-02-03Bibliographically approved
Abate, M. (2014). Economic effects of air transport market liberalization in Africa. Stockholm: CTS
Open this publication in new window or tab >>Economic effects of air transport market liberalization in Africa
2014 (English)Report (Other academic)
Abstract [en]

Although the aviation industry is increasingly becoming important for Africa's economic development and integration, the ability of airlines to access foreign markets remains hindered by restrictive regulatory policies. Attempts have been made to fully liberalize the intra-African air transport market. Except for general assertions about the merits/demerits of liberalization, our empirical understanding of the welfare effects of such polices in Africa remains rudimentary. This study empirically measures the economic effects of air transport liberalization, mainly on two supply side variables: fare and service quality, measured as departure frequency. The results show up to 40 % increase in departure frequency in routes that experienced some type of liberalization compared to those governed by restrictive bilateral air service agreements. While the effect of liberalization is substantial in improving service quality, there is no evidence of its fare reducing effect.

Place, publisher, year, edition, pages
Stockholm: CTS, 2014. p. 28
Series
CTS Working Paper ; 2014:23
Keywords
Air transport, Deregulation, Market, Demand (econ), Price, Mathematical model, Economics of transport
National Category
Economics
Research subject
SAB, Prd Aircrafts, air transport and airports
Identifiers
urn:nbn:se:vti:diva-7418 (URN)
Available from: 2014-11-11 Created: 2014-11-11 Last updated: 2016-02-03Bibliographically approved
Abate, M., Vierth, I. & de Jong, G. (2014). Joint econometric models of freight transport chain and shipment size choice. Stockholm: Centre for Transport Studies
Open this publication in new window or tab >>Joint econometric models of freight transport chain and shipment size choice
2014 (English)Report (Other academic)
Abstract [en]

In freight transportation, decisions regarding the choice of transport mode (or chains of modes) and shipment size are closely linked. Building on this basic insight, in this paper we estimate and review various joint econometric models using the Swedish National Commodity Flow surveys. Robust parameter estimates from this exercise will be used to update the current deterministic Swedish national freight model system (the SAMGODS model) to a stochastic one.

Place, publisher, year, edition, pages
Stockholm: Centre for Transport Studies, 2014. p. 34
Series
CTS Working Paper ; 2014:9
Keywords
ransport mode, Freight transport, Transport chain, Transport operator, Modal choice
National Category
Transport Systems and Logistics Business Administration
Research subject
J00 Railway: General works, surveys, comprehensive works, J05 Railway: Freight transport; 10 Road: Transport, society, policy and planning, 12 Road: Freight transport; SAB, Prz Ships and shipping
Identifiers
urn:nbn:se:vti:diva-6890 (URN)
Available from: 2014-05-12 Created: 2014-05-12 Last updated: 2018-11-23Bibliographically approved
Vierth, I., Jonsson, L., Karlsson, R. & Abate, M. (2014). Konkurrensyta land–sjö för svenska godstransporter. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Konkurrensyta land–sjö för svenska godstransporter
2014 (Swedish)Report (Other academic)
Alternative title[en]
Competition between land based modes and sea transports for Swedish freight transports
Abstract [sv]

I den här rapporten presenteras resultaten av en undersökning om konkurrensytan mellan väg och järnväg å ena sidan och sjöfarten å andra sidan för godstransporter i, till och från Sverige. Varuägare väljer olika transportkedjor för att frakta olika typer av gods. Transportpriserna är en central faktor vid valet av transportkedja. Priser för sjötransporter, som sätts på världsmarknaden, fluktuerar mer än priser för väg- och järnvägstransporter. Bland annat för internationella transporter till/från kontinenten leder obalanser i transportflöden till lägre priser för sydgående vägtransporter och norrgående järnvägstransporter. Enligt statistiken har transportarbetets fördelning på trafikslagen, i tonkilometer på svenskt territorium, varit relativt konstant sedan 1990; knappt 40 procent transporteras på väg, knappt 40 procent transporteras med sjöfart och drygt 20 procent med järnväg. Simuleringar med Samgodsmodellen med tio procent lägre undervägskostnader för lastfartyg indikerar olika anpassningar för olika varugrupper. Transportarbetet med sjöfart på svenskt territorium beräknas öka cirka två procent om modellens samtliga 33 varugrupper inkluderas. För varugrupperna ”Cement, kalk och byggnadsmaterial” och ”Pappersmassa, returpapper och pappersavfall” beräknas ökningar på nästan tio procent, medan efterfrågan inte påverkas nämnvärt för ”Råolja”, som transporteras uteslutande med fartyg idag. Som förväntat beräknas större konkurrensytor för utrikestransporter än för inrikestransporter. Om alla varugrupper inkluderas erhålls de största ökningarna för sjötransporter längs ostkusten (södra delen), sydkusten och genom Kielkanalen. Transportarbetet med sjöfart beräknas också öka längs Norrlandskusten och till och från Göteborg på västkusten. Minskningar beräknas ske både för väg och järnväg. Författarna betonar att resultaten bör ses som indikationer. Avslutningsvis listar rapporten olika trender och faktorer som gynnar respektive missgynnar de olika trafikslagen.

Abstract [en]

This project aims to investigate the competition between road and rail transports on one hand and the sea transports on the other. Shippers choose different unimodal or multimodal transport chains to carry various types of goods in, to and from Sweden. Transport prices are a key factor when choosing the transport chain. Sea transport prices are set on the world market and fluctuate more than prices for road and rail transports. Imbalances in transport flows also affect the intermodal competition, in particular for transports to/from mainland Europe. According to the statistics the modal split, measured in tonne-kilometers on Swedish territory (including a stretch along the coast) has been relatively constant since 1990. Nearly 40 percent of the tonne-kilometers are carried out by road, nearly 40 per cent by sea and a bit more than 20 per cent by rail. Sweden had so far by definition not inland waterway transports. Simulations with the national Swedish freight model Samgods with ten percent lower on-route costs for vessels indicate different adaptations for different commodity groups. The tonne-kilometers by sea performed on the Swedish territory are expected to increase by about two per cent if all 33 commodities are included. However, for Cement, lime and building materials and Pulp, paper and paper waste increases of almost ten percent are computed. On the other hand, no significant changes in demand are calculated for i.e. Crude oil, which is carried exclusively by sea today. As expected, more competition between the land-based modes and sea transports is calculated for international transports than for domestic transports. If all commodities are included, the largest increases for sea transports are calculated along the Eastern coast (southern part), the Southern coast and through the Kiel Canal. Sea transports are also calculated to increase along the coast in the North of Sweden and to/from Gothenburg on the Western coast. Reductions are expected to occur for both road and rail. The authors emphasize that the results should be seen as indicative.

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2014. p. 54
Series
VTI rapport, ISSN 0347-6030 ; 822
Keywords
Freight transport, Transport mode, Competition, Modal split, Cost, Freight, Maritime transport, Rail bound transport, Road transport
National Category
Economics
Research subject
10 Road: Transport, society, policy and planning, 12 Road: Freight transport; J00 Railway: General works, surveys, comprehensive works, J05 Railway: Freight transport; SAB, Prz Ships and shipping
Identifiers
urn:nbn:se:vti:diva-6926 (URN)
Available from: 2014-07-14 Created: 2014-07-14 Last updated: 2018-11-23Bibliographically approved
Abate, M. & De Jong, G. (2014). The optimal shipment size and truck size choice: The allocation of trucks across hauls. Transportation Research Part A: Policy and Practice, 59, 262-277
Open this publication in new window or tab >>The optimal shipment size and truck size choice: The allocation of trucks across hauls
2014 (English)In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 59, p. 262-277Article in journal (Refereed) Published
Abstract [en]

There has been a growing interest in understanding how firms allocate their trucks across hauls, and how this allocation changes under various economic environments. This study investigates how variations in route/haul, carrier and vehicle characteristics affect the optimal vehicle size choice and the associated choice of shipment size. We show that the two choices are derived from the same optimization problem. There can be a continuum of shipment sizes, but decision-makers in freight transport have to choose from a limited number of vehicle alternatives. Therefore, we use a discrete-continuous econometric model where shipment size is modeled as a continuous variable, and vehicle size/type choice as a discrete variable. The results indicate that when faced with higher demand, and during longer trips firms are more likely to use heavier vehicles and ship in larger quantities which suggest that firms are realizing economies of scale and economies of distance. The study also discusses the effect of vehicle operating cost on the vehicle selection process and its policy implications.

Keywords
Freight transport, Choice, Lorry, Size, Weight, Freight, Optimization, Demand (econ), Mathematical model
National Category
Transport Systems and Logistics
Research subject
10 Road: Transport, society, policy and planning, 12 Road: Freight transport
Identifiers
urn:nbn:se:vti:diva-9369 (URN)10.1016/j.tra.2013.11.008 (DOI)
Available from: 2016-05-04 Created: 2016-03-02 Last updated: 2017-11-30Bibliographically approved
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