Modelization of Time-Dependent Urban Freight Problems by Using a Multiple Number of Distribution Centers

Freight transport is essential to modern urban civilization. No urban area could exist without a powerful freight transport system. However, the distribution of perishable foods in urban areas is seen as a source of problems, due to traffic congestion, time pressures, and environmental impact. In this paper, an Agent-Based Model integrated with Geographic Information Systems (ABM-GIS) is designed for a time-dependent vehicle routing problem with time windows. This simulation model consists of determining the quickest routes to transport fresh products, estimating Vehicle kilometer traveled VKT and vehicle hour traveled VHT where speeds and travel times depend on the time of the day. Based on a case study, analyses of changes on traffic condition were conducted to get an insight into the impact of these changes on cost, service quality represented by the respect of time windows, and carbon emissions. The results reveal that traffic jams and restrictive time windows lead to additional cost, cause delays, and increase co2 emission. As for a short-term planning, time-dependent scheduling algorithm was proposed and assessed while extending time windows. Results have proved the potential saving in cost, travel time, and carbon emission.

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Urban Freight in Dublin City Center, Ireland

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198105190600104 ◽

2005 ◽

Vol 1906 (1) ◽

pp. 33-41 ◽

Cited By ~ 3

Author(s):

Clare Finnegan ◽

Hugh Finlay ◽

Margaret O'Mahony ◽

Donal O'Sullivan

Keyword(s):

Real Life ◽

Distribution Centers ◽

City Center ◽

Urban Freight ◽

Logistics Service ◽

Last Mile ◽

Logistics Service Provider ◽

Delivery Platform ◽

Urban Distribution ◽

The City

Findings are presented from a study evaluating sustainable freight distribution in the city center of Dublin, Ireland, particularly focusing on urban distribution centers (UDCs) and managing the last mile of deliveries. A survey of city center organizations is described, and relevant delivery patterns (origin, destination, type of goods delivered) are compared with those from a previous feasibility analysis to determine UDC opportunities in Dublin. A real-life commercial example of a UDC is also described. Ireland's largest grocery distributor operates this UDC. The operational efficiencies and the wider benefits of the UDC are discussed. In addition, a commercial example of managing the last mile of deliveries through a city center delivery platform is detailed. The delivery platform is managed by a leading logistics service provider.

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Assesment of the potential of cargo bikes and electrification for last-mile parcel delivery by means of simulation of urban freight flows

European Transport Research Review ◽

10.1186/s12544-021-00491-5 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Carlos Llorca ◽

Rolf Moeckel

Keyword(s):

Operating Time ◽

Low Noise ◽

Electricity Production ◽

Distribution Centers ◽

Agent Based ◽

Urban Freight ◽

Last Mile ◽

Last Mile Delivery ◽

Parcel Deliveries ◽

Motorized Vehicles

Abstract Background The paper presents a simulation model for freight. In the paper, this model is applied to understand the impacts of electric vans and cargo bikes for the last-mile delivery of parcels. Cargo bikes are electrically assisted vehicles that distribute parcels from micro depots located close to the final customers by means of short tours. The parcels are sent from the major distribution center to micro depots in vans (called feeders). Materials and methods An agent-based model is used for the purpose of the paper. The model is based on the disaggregation of commodity flows to represent trucks (for all commodities) and individual shipments (for parcel deliveries). The model represents microscopically every freight vehicle in the study area. Results The simulation of various scenarios with different shares of cargo bikes and electric vans assesses the impacts of electrification and cargo bikes. The use of cargo bikes to deliver parcels allows to reduce the number of motorized vehicles, although the presence of large parcels requires that at least half of deliveries by vans are still required. The shift to cargo bikes represents a slight increase in the total operating time to deliver the parcel demand. With low shares of cargo bikes, the total distance traveled increases, since the reduction of van tours cannot compensate the additional feeder trips from distribution centers to micro depots. The cargo bikes also do not reduce the number of vehicles for the served area, but modify the composition of vehicle types. Low noise, smaller, low emission vehicles increase, while delivery vans are reduced. Conclusion Both cargo bikes and electric vans are able to reduce CO2 emissions, even after accounting for the emissions related to electricity production.

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