road system history?

Question

This road system was built primarily for the purpose of allowing

people to travel to religious festivals.
farmers to carry tribute to the Sapa Inca.
armies and news to move rapidly throughout the empire.
traders to come into the empire.

Answer 1

I thought it was for military purposes but it seems every country or nation used it for different purposes, the Romans used it for military and economic purposes:

The oldest engineered road discovered is the Sweet Track causeway in England, dating from around 3800 BC.

The ancient Egyptians constructed a stone paved road to help move materials for the building of the Great Pyramid in about 3000 BC.

The ancient Chinese constructed an extensive system of roads, some paved, from about 1100 BC onwards. By 20 AD, the Chinese road network extended over 40,000 kilometres.

The Incas built fine highways, the Inca road system, for couriers through the Andes, and the Mayans built an extensive network of paved roads in Mexico before the European discovery of the New World.

In ancient times, transport by river was far easier and faster than transport by road, especially considering the cost of road construction and the difference in carrying capacity between carts and river barges. A hybrid of road transport and ship transport is the horse-drawn boat in which the horse follows a cleared path along the river bank.

In 500 BC, Darius I the Great started an extensive road system for Persia (Iran), including the famous Royal Road which was one of the finest highways of its time. The road was used even after the Roman times. Because of the road's superior quality, mail couriers could travel 2,699 km in seven days.

From about 300 BC, the Roman Empire built straight strong stone Roman roads throughout Europe and North Africa, in support of its military campaigns. By the 1st century the Roman Empire was connected by 85,000 kilometers of paved roads.

Vikpedia.

Answer 2

Among the many roads and trails constructed in pre-Columbian South America, the Inca road system (El Camino Inca) of Peru was the most extensive. Traversing the Andes mountains and reaching heights of over 5,000 m (16,500 feet) above sea level, the trails connected the regions of the Inca empire from the northern provincial capital in Quito, Ecuador past the modern city of Santiago, Chile in the south. The Inca road system covered approximately 22,500 km (14,000 mi) and provided access to over three million km² of territory.