What should you do if you notice that vehicles are parked by a roundabout?

When approaching a roundabout where vehicles are parked, reducing your speed is the most prudent action. This approach allows you to assess the situation safely and observe any potential hazards posed by the parked vehicles. Parked vehicles can obstruct visibility and may cause confusion about the flow of traffic, potentially hiding pedestrians or other road users who may be in the vicinity. By lowering your speed, you give yourself more time to respond appropriately to any unexpected situations that may arise.

Other choices, such as ignoring the parked vehicles or attempting to overtake without assessing the situation, could lead to dangerous conditions. Honking might not effectively communicate the necessary caution and could be perceived as aggressive, which is often unnecessary and could escalate tensions on the road. Reducing speed is the safest and most responsible action to take in this scenario.