An estimate of 400,000 vehicles take on the city streets and roads every day.  The oldest districts were not built with the advent of the automobile in mind and therefore lack efficient roadways to accommodate the overwhelming number of vehicles.  Newer developments, such as the malls, have been built with the car in mind allowing for large parking lots to accommodate their visitors.  In the last decades, several of the boulevards and avenues have been retrofitted with grade separations to ease up the flow of traffic.