Which intersection type is considered the safest and most efficient?

• A. A two-lane signalized intersection
• B. A one-lane roundabout
• C. A four-way stop with traffic signals
• D. A multilane roundabout

Answer: (B)

A one-lane roundabout is safest and most efficient because it uses yield control and gentle, low speeds to dramatically reduce crash opportunities and keep traffic moving smoothly. In a single-lane circle, entering drivers yield to those already circulating, which minimizes the chances of high-speed angle or head-on crashes and limits the need to stop and start frequently. The result is fewer severe crashes and shorter overall delays than traditional signalized or stop-controlled intersections.

Compared with a two-lane signalized intersection, signals create more stops and retries, and the potential for rear-end crashes increases when gaps open and close. A four-way stop with signals tends to introduce stop-and-go timing and inconsistent gaps, which slows traffic and raises driver stress. A multilane roundabout adds complexity with lane changes inside the circle, increasing opportunities for side-swipe and weaving conflicts. The simplicity of a single lane keeps design and driver behavior straightforward, leading to safer, steadier flow across a wide range of conditions.