Dynamic optimisation of urban intermodal freight transport with random transit times, flexible tasks and time windows

Es una ponencia de The Sixth International Conference on City Logistics, en Puerto Vallarta, México http://toc.proceedings.com/18996webtoc.pdfAn improvement on drayage operations is necessary for intermodal freight transport to become competitive. When drayage takes place in cities or urban centres transit times are usually random, as a consequence finding the optimal fleet schedule is very difficult, and this schedule can even change during the day. The work we present here is a dynamic optimisation model which uses real-time knowledge of the fleet’s position, permanently enabling the planner to reallocate tasks as the problem conditions change. Stochastic trip times are considered, both in the completion of each task and between tasks. Tasks can also be flexible or well-defined. We describe the algorithm in detail for a test problem and then apply it to a set of random drayage problems of different size and characteristics, obtaining significant cost reductions with respect to initial estimates.Junta de Andalucía SR0197/200

Traffic Risk Generated by Large Urban Commercial Centers

AbstractAs a consequence of development policies urban areas are substantially different in terms of road traffic risk. The shape, size and configuration of urban areas, the transport supply to meet people and goods mobility needs, as well as human behavior have huge influence on the road traffic volume and pattern and, hence, on the associated road crash risk. In this context, the paper reveals the effects of locating large shopping centers in the central areas of the city on the already over-congested road network. We use specific spatial analysis models in order to estimate vehicle and customers flows, attracted by one of the largest shopping malls in Bucharest. This approach gives theoretical and practical added value to the study: providing analysis tools to local decision makers for the ex-ante assessment of the consequences of locating large malls, in terms of traffic flow and associated crash risk

Electric vehicles: the solution to emissions from transport?

The environmental impacts of all industry sectors are coming under more and more scrutiny around the world, given the current focus on climate change, environmental impacts and energy security. The transport sector is included in this scrutiny; it is responsible for about14% of Australia's C02 emissions, with about half of this is due to passenger and light commercial vehicles. Furthermore, greenhouse gas emissions from transport have grown by29% since 1990. One technology that can contribute to sustainable transport is that of electric vehicles,including electric-assisted bicycles, electric scooters and motorcycles, and electric passenger vehicles. The main advantage of electric vehicles is that they can be recharged using electricity generated from clean, renewable energy sources, at a lower environmental and monetary cost than a petrol or diesel car. The main disadvantage of electric vehicles is that they have limited range and long recharge times compared to fossil-fuelled vehicles, and so can not match the versatility of conventional cars. However, low-mass electric vehicles aremuch better suited to the short commutes that make up almost all of the trips made by conventional cars. Refereed/Peer-reviewe

Planning for electric vehicles in Australia - Can we match environmental requirements, technology and travel demand?

Refereed/Peer-reviewe