What are roads designed to bypass city centers to alleviate traffic congestion called?

Roads designed to bypass city centers to alleviate traffic congestion are commonly known as ring roads. These circular routes encircle urban areas and allow vehicles to travel around the city instead of through it, reducing congestion in the city center. By facilitating easier access to and from various neighborhoods and regions without passing through densely populated areas, ring roads improve traffic flow and enhance transportation efficiency.

Bypass roads, while similar in function, typically refer to roads that divert traffic around a specific town or urban area rather than in a circular configuration, which is what distinguishes them from ring roads. Expressways and thruways generally denote high-speed roadways that may not specifically focus on bypassing urban centers, often accommodating longer-distance travel rather than directly addressing city traffic congestion. Thus, ring roads are specifically designed with the intent to manage urban traffic around city centers.