Step 1: Understanding the Concept:
The question asks to identify the best mode of transport based on specific criteria: large volume, bulky materials, and long distances over land.
Step 2: Detailed Explanation:
Let's evaluate each mode based on the criteria:
1. Air Transportation: This mode is very fast but also very expensive. It is best suited for light, high-value, or perishable goods, not for large volumes of bulky materials like coal or iron ore.
2. Road Transportation: Trucks offer great flexibility (door-to-door service) but are less efficient and more costly than rail for moving very large quantities of bulk goods over very long distances.
3. Rail Transportation: Railways are ideal for transporting heavy and bulky goods (like minerals, grains, fertilizers, and containers) in large quantities over long terrestrial distances. They are more energy-efficient and cost-effective than road transport for such tasks.
4. Pipelines: These are highly efficient but are specialized for transporting liquids and gases (like oil, natural gas, and water), not general bulky materials.
Step 3: Final Answer:
For large volumes of bulky materials over long land distances, rail transportation is the most suitable mode.