What is a common obstacle faced during the diminishing clearance driving exercise?

In the diminishing clearance driving exercise, the presence of parked cars is indeed a common obstacle. This exercise simulates scenarios where a driver must navigate through narrow spaces, often found in urban environments. Parked cars can significantly reduce the available width of the roadway, requiring the operator to maintain a high level of awareness and skill in managing the vehicle's clearance. This scenario involves calculating the distance between the vehicle and the parked cars while also considering the vehicle's dimensions and turning radius.

While traffic cones may be used to mark the course of the exercise, they typically serve a guiding function rather than being a true obstacle that impacts the driver’s navigation capability in real situations. Potholes can create a hazard but are less likely to impede the navigation through a diminishing clearance exercise focused on clearance-related challenges. Pedestrians are a concern in driving but are generally outside the scope of clearance exercises, which specifically concentrate on spatial awareness regarding fixed objects like parked vehicles.