Road transport such as car or truck is the most common mode of transportation for inter-city transport. Air transportation is also common, but only for high-valued products. Railway transport is more common for hauling heavy cargo loads.
Being the 11th largest economy in the world, not only finished products travel through Mexico; foodstuffs, raw materials and capital goods move through roads, railroads and shipping lanes.
People and goods travel in Australia by cars, I guess.
Yes, individuals with a green card can travel to Mexico.
As for services, none really. On goods, Mexico mostly imports "capital goods", which are all products needed to build or manufacture other goods.
No, a child cannot travel to Mexico without a passport.
Yes, Brazilians need a visa to travel to Mexico.
Yes, Peruvians need a visa to travel to Mexico.
Yes, babies need a passport to travel to Mexico.
Yes, babies need passports to travel to Mexico.
Yes, children need a passport to travel to Mexico.
Yes, infants need a passport to travel to Mexico.
Yes, infants need passports to travel to Mexico.