%MÉTODOS: The model reads streets as vectorial lines using the \textbf{sp} package and includes several constructor classes. Each class has units from the \textbf{units} package.
%CONCLUSAO: This paper describes the methodology of a new R package for high resolution bottom-up vehicular emissions inventories, named VEIN. The model provides a new and fast way of elaborating and analyzing vehicular emissions inventories.  The output of the model can also be incorporated in high resolution air quality models.Future versions of VEIN will include additional emissions factor options for other countries/territories.

%CARTA: The paper shows the estimation of CO for a traffic simulation in the western area of São Paulo City, Brazil. This paper also provides instructional examples for the VEIN package. 	 The output of the model can also be incorporated in high resolution air quality models.Future versions of VEIN will include additional emissions factor options for other countries/territories.