Final answer:
The Romans were able to macadamize a large portion of the Italian peninsula by building roads using a method of compacting layers of small stones. They used advanced engineering skills and concrete in their construction, resulting in an extensive road system that allowed for trade, troop movement, and cultural assimilation.
Step-by-step explanation:
The Romans were able to macadamize a large portion of the Italian peninsula. Macadamize means to build roads using a method of compacting layers of small stones. The Romans were known for their advanced engineering skills and their extensive use of concrete in construction. They built roads using stones and concrete, which are still visible today. Their road system extended across the entire empire, with a total length of 40,000 miles. This infrastructure allowed for efficient trade, troop movement, and cultural assimilation.