Input (grade 13): Laredo International Airport is within the Laredo city limits, while the Quetzalcoatl International Airport is nearby in Nuevo Laredo in Mexico.
Output (grade 12): Laredo is a border city which is part of the bi-national metropolitan area of Laredo, Texas - Nuevo Laredo, Tamaulipas, Mexico with a total population of 575,585. The main sources of income for Laredo is international trade, followed by retail sales.