Mathematics for calculating the flow of goods in the cities vehicles
December 10, 2010
It had been used to estimate the flow of private vehicles in a city but it is the first time that this mathematical model-, which carries out assignments of balance (i.e.) is used in combination with commercial Simulator Emme/2(, calculations of traffic flows) using a divided into areas and a matrix point-to-point (O-D) urban network - to calculate the greater or lesser circulation of goods vehicles. Researchers at the University of Seville with the help of the National Plan of r & d have done so and have recently published their application in the journal Computers and Industrial Engineering.
The goal, "include estimates of the movement of goods obtained in simulators of traffic of people and thus help Councils to improve the overall flow of the city," explains Jesus Muñuzuri, one of those responsible for the project. "What is new is the application of the mathematical model and, for the moment, we have done with success in peak traffic in Sevilla (9-10 in the morning on weekday);" We have matched city the estimate with the actual flow data and are obtained values reasonably close, which can be used for subsequent calibrations of the model. But also the way to get the data into the spreadsheet - assures - has been interesting. In addition to the official statistics on population density, number of shops, location, number of trucks and vans with license of transport (5.823 in Seville, on data from 2008) and other details, we have carried out surveys aimed at merchants (is the first time that is)", rather than carriers, in other cases, which are forced to give much less information".
The advantage of this model is, among other things, "simplicity, others need more data" (...). "The idea is to give a valid representation of reality in a specific location", he argues. The next step is to apply the model to the full day, verify that it works, "and then play with the results considering questions like what if you restrict access for a site or another?" And if I set up a new centre of unloading of goods? ", adds." Once the model is tuned, "we want to make comparisons with other European cities," explains Muñuzuri.
Aid to improve the policies of traffic in the city is one of their utilities. However, you can also have an environmental aspect which already have tested these researchers, since it would serve "to calculate the ecological footprint of this type of transport in the town in question, to be able to propose alternatives for reduction of the same".