Sergio Úbeda Munárriz

Sergio Úbeda Munárriz, industrial engineering graduate from the Public University of Navarre (UPNA), has devised an algorithm that enables the generating of environmentally-efficient (cleaner and less contaminant) road vehicle routes.

As regards transport, that involving road vehicles is the factor with the greatest environmental impact (83.7%), followed by air transport (14%). Since the 90s there has been a growing interest in finding solutions to reduce the contaminant emissions thus caused: better design of vehicles, new fuels, efficient driving, control of traffic levels and efficient operational planning. It is this last aspect that the research work of Sergio Úbeda has concentrated on.

In his PhD thesis, Mr Úbeda analysed the models for the estimation of CO2 emissions and those drawn up for calculating and planning routes for the transport of goods. “it is not a new model that is being presented”, explained Mr Úbeda, “but an adaptation of existing methods to enable them to include environmental variables and to calculate those routes that generate lower levels of contaminant emissions. That is, we turn the objective round – before, we devised the shortest or most economic routes while now it is the cleanest or least contaminant”.

Up to recently, the models for estimating CO2 emissions did not form part of any application for generating and designing routes for the transport of goods. CO2 emissions can only be estimated, given that the calculation of this parameter for each vehicle is highly complex and depends on diverse factors such as the characteristics of the vehicle, the type of fuel used, route conditions (orography, degree of congestion, etc.), style of driving, and weather conditions, amongst others.

“Obviously, road freight companies only have control over the characteristics of the vehicle and the load transported, and thus the research focused on this aspect”, pointed out Mr Úbeda. “We devised a function that enabled us to estimate the fuel consumption and the emissions factor for various kinds of vehicles depending on the characteristics of the distribution process and taking into account the load transported and the sequences of delivery”.

The devised algorithm was applied for resolving a series of cases based on the distribution data of the Eroski Group, with which the UPNA has signed a framework agreement the goal of which is to analyse the potential of the logistical activity of the Group in environmental matters. “This application to real cases has helped us to respond to two questions: how the typology of the distribution network influences the solution obtained and what effect the environmental function has on the planning of routes”.

Green and sustainable routes

According to the researcher, in general the optimisation criteria for emissions guarantee the construction of greener routes. “Nonetheless, it has been observed that the shortest routes are not always the most sustainable and, at times, there is divergence between the objectives of environmental efficiency and those of efficiency, in terms of distance and monetary cost”.

Taking the current market price of rights to CO2 emissions (allowances), incorporating the external cost into the accounts of transport expenditure would represent an increase of approximately 2% of the current cost. This would also increase if other external factors such as traffic noise and congestion were takin into consideration.

In those cases in which there has been a divergence of solutions between objectives, the principal variation arose in the order of visits or deliveries to customers. This order is affected by two parameters controlling the level of emissions: the distance between customers and the amount of goods transported between them. “These show that the design of the distribution network and its optimisation contributes to minimising the environmental impact generated by transport activities and also the importance of taking into account the environmental variable when optimising the logistics of transport operations”.

Mr Úbeda highlights the results of the research in the following manner “They provide a new business vision of the integrated management of transport and its environmental effects, and the conclusions drawn have practical application in the consumer goods distribution sector”. In this vein, he points out that “practices such as the consolidation or incorporation of loads on empty return journeys are both environmentally efficient and cost effective”.

Mr Úbeda’s PhD, “Green logistics in the distribution chain. Ecoefficient planning of vehicle routes”, directed by Professor of Statistics and Operational Research at the UPNA, Javier Faulín Fajardo, and by Emeritus Professor at the University of New Brunswick (Canada), Francisco Javier Arcelus Ulibarrena, was awarded “excellent”.

* Elhuyar translation, published in www.basqueresearch.com