What is a vehicle that transports coal or workers called?

The vehicle that specifically transports coal or workers within the mining context is referred to as a shuttle car. Shuttle cars are essential in underground mining operations as they are designed to quickly and efficiently move material, such as coal, from the working face of a mine to a designated loading area or conveyor system. These vehicles are equipped with a hopper or bed that is capable of carrying the bulk material, facilitating continuous operation and enhancing productivity in coal mining.

In contrast, other terms mentioned do not pertain specifically to the transport of coal or miners in the same way that shuttle cars do. Carts are generally more simplistic vehicles and not specialized for the mining environment, while conveyors are fixed systems used to transport materials continuously but do not move independently like shuttle cars. The term "trip" can refer to a movement or cycle of materials and vehicles but is not a specific vehicle itself in the context of transporting coal or personnel in mining operations. Thus, shuttle cars are the correct answer, as they fulfill the specialized function of transporting both coal and miners efficiently.