Categorize the following item into the appropriate class.
Bus
A bus is categorized under the class of vehicle, specifically a heavy-duty road vehicle designed for transportation of passengers.
Complete the following task based on the instruction and optional input provided.### Instruction:
Categorize the following item into the appropriate class.

### Input:
Bus

### Output:
A bus is categorized under the class of vehicle, specifically a heavy-duty road vehicle designed for transportation of passengers.