What could make a vehicle unsuitable for road use?

A vehicle can become unsuitable for road use based on various factors, and one important aspect is the condition of its windshield. If the windshield is cracked or significantly damaged, it can obstruct the driver's vision and compromise safety. Clear visibility is essential for safe driving, and any impairment to this could lead to accidents or hazards on the road.

While the appearance of the exhaust or interior cleanliness may impact the overall aesthetics of the vehicle, they are not as directly tied to safety and operational suitability. The audible warning equipment is crucial for vehicles like ambulances, but if it is operational, its presence alone does not determine road worthiness. Hence, the condition of the windshield stands out as a critical factor that directly affects a vehicle's safety for road use.