What is often referred to as the bloodstream of a city?

The transportation system is often referred to as the bloodstream of a city because it plays a crucial role in the movement of people, goods, and services. Just as blood circulates through the body to deliver nutrients and remove waste, the transportation system facilitates connectivity and accessibility within urban areas. It includes roads, highways, railways, and bike lanes, enabling residents to travel and interact with various sectors of the city, such as workplaces, schools, and recreational areas.

This interconnected nature of the transportation network supports economic activity and social exchange, allowing a city to function efficiently. A robust transportation system is vital for urban planning, as it influences land use, economic development, and overall quality of life for residents.

Other options, while important components of urban infrastructure, do not encapsulate the same holistic and dynamic function that the transportation system fulfills within a city's structure. For example, the utility grid provides essential services such as water and electricity, while commercial districts focus on business activities. Public transit is a part of the transportation system but does not capture its entirety. Thus, the transportation system's comprehensive nature solidifies its role as the “bloodstream” of the city.