What must a driver do when approaching a roundabout?

When approaching a roundabout, it is essential for drivers to yield to traffic that is already in the roundabout before they enter. This rule is designed to ensure safety and smooth flow through the roundabout, as vehicles inside the roundabout always have the right of way.

By yielding, drivers allow for safe merging and help prevent collisions, maintaining an orderly flow of traffic. Understanding this concept is vital, as it distinguishes the behavior expected of drivers when navigating these intersections, which are designed to enhance traffic efficiency and reduce the likelihood of accidents.

The other choices do not align with proper roundabout etiquette. Speeding up could lead to unsafe conditions or accidents, while stopping completely is unnecessary and could disrupt traffic flow. Using a left turn signal upon entry is also incorrect, as drivers should use their signals only when changing lanes or exiting the roundabout, rather than when entering.