Traffic moves smoothly in a roundabout because vehicles ____ .*1 pointA. Move only to the rightB. Move only to the leftC. Yield instead of stopD. Both A and C

Breakdown of the Problem

The question asks for the reason why traffic moves smoothly in a roundabout, presenting four answer options.

Relevant Concepts

Roundabouts are designed to improve traffic flow and safety by reducing the number of conflict points, allowing vehicles to keep moving while yielding to oncoming traffic.

Analysis and Detail

1. Option A (Move only to the right): In countries where driving is on the right, vehicles indeed move to the right within a roundabout, but this is not universally applicable (as countries may have different driving rules).

2. Option B (Move only to the left): This is incorrect for nations where driving is on the right, as vehicles do not predominantly move left.

3. Option C (Yield instead of stop): This is an important feature of roundabouts; vehicles yield to the traffic already in the roundabout, reducing stops and keeping traffic flowing.

4. Option D (Both A and C): Since vehicles yield in addition to moving in a specific direction (to the right in right-hand driving countries), this option encapsulates both aspects that contribute to smooth traffic flow in roundabouts.

Verify and Summarize

Upon reviewing the options, it's important to note that vehicles yield to come into the roundabout and maintain a right-turning direction in right-hand driving countries. Therefore, the best answer leverages both key factors.

Final Answer

The answer is D. Both A and C.