Final answer:
Roman roads were not inexpensive and simple to construct, but rather engineered and built to a high standard with the use of concrete and stones.
Step-by-step explanation:
The fact about Roman road systems that is false is d) They were inexpensive and simple to construct. Roman roads were actually engineered and built to a high standard, using concrete and stones. They were designed to be durable and long-lasting to accommodate the movement of troops and facilitate trade and commerce throughout the empire. Roman road construction was a complex process that involved the use of multiple layers of materials, culverts for drainage, and precise engineering techniques.