Which design is characterized by the driver’s seat above the steering axle?

The cab-over design is characterized by the driver's seat being situated above the steering axle. This configuration allows for a more compact vehicle design, providing better maneuverability and maximizing cargo space in urban environments. The cab-over design also ensures that the driver has enhanced visibility due to the positioning of the seat, which can contribute to improved safety.

In contrast, the conventional design features a long hood with the driver's seat set back behind the engine, which can make the vehicle longer and less agile in tight spaces. The forward control design may share similarities with cab-over configurations but is not universally recognized in the same way. Semi-trucks, while often referring to vehicles with trailers, usually have a conventional design and thus do not fit the criteria of having the driver's seat above the steering axle.

This unique structure of the cab-over design is why it stands out in this context, meeting the specifications outlined in the question.