Transport and Communication in the World
Senior 6 · Geography
Transport and Communication in the World
Lesson 1 of 4
25 min
A container of machine parts leaves a factory in China by lorry, crosses the Indian Ocean on a ship carrying thousands of other containers, is lifted onto a lorry at Mombasa or Dar es Salaam, and is driven along roads through Kenya and Uganda or through Tanzania to Kigali. The same steel box uses three or more modes of transport without ever being unpacked. Sea transport carries over 80% of the volume of world trade in goods, and in 2024 ships moved about 12.7 billion tonnes of cargo (UNCTAD, Review of Maritime Transport 2025). Air transport carries far less weight but the most valuable and urgent goods, and in 2023 airlines carried about 4.3 billion passengers (World Bank).
Definition
Transport: the movement of people and goods from one place to another.
Mode of transport: a type of transport: road, rail, water (inland and ocean), air or pipeline; porters, animals and cableways are others.
Terminal costs: fixed costs of loading, unloading and handling at stations, ports and depots, paid whatever the distance. Line-haul costs: the costs of moving goods along the route, which rise with distance.
Intermodal transport: moving goods by two or more modes in the same container or load unit. Containerization: carrying goods in standard steel boxes, measured in twenty-foot equivalent units (TEU).
Break of bulk: a place where goods are transferred from one mode to another, such as a port or a railway terminal.
| Mode | Advantages | Disadvantages |
|---|---|---|
| Road | Door-to-door service; flexible routes and times; cheap to build compared with railways; low terminal costs; best for short distances and small loads; reaches rural areas | High cost per tonne-km over long distances; small loads; congestion, accidents and air pollution; roads damaged by heavy lorries and floods |
| Rail | Carries heavy, bulky goods (minerals, fuel, grain, containers) cheaply over long distances; less congestion; fewer accidents and lower emissions per tonne than road | Very costly to build, especially in hilly country; fixed routes; goods must be transferred to roads at each end; different gauges block through traffic |
| Inland water (rivers, lakes, canals) | Cheapest per tonne-km for bulky goods; natural routes cost little to build | Slow; rapids, falls, seasonal low water and ice block navigation; rivers may not run where goods are needed |
| Ocean | Huge loads at very low cost per tonne; links all continents; essential for world trade | Slow; needs costly ports; vulnerable to storms, piracy and blocked canals; landlocked countries need land routes to reach it |
| Air | Fastest over long distances; crosses mountains, seas and forests; ideal for passengers, perishable and high-value goods (flowers, medicines, electronics) | Most expensive per tonne-km; small loads; high fuel use and emissions; airports are costly and need much land |
| Pipeline | Continuous, cheap flow of liquids and gas once built; little labour; underground and safe from weather | High building cost; carries only fluids, one way; leaks and theft; fixed route |
Why is road cheapest for short trips but water cheapest for long ones? Each mode has a different mix of fixed terminal costs and costs per kilometre (Figure 1). Road has low terminal costs but high line-haul costs, so its line starts low and rises steeply. Water has high terminal costs at ports but very low line-haul costs. Where two lines cross, the cheaper mode changes.
Figure 1: Transport cost and distance for road, rail and water (illustrative figures).
Rwanda's position. Rwanda has no railway yet, so almost all its imports and exports travel by road to and from the ports of Mombasa and Dar es Salaam. Air freight through Kigali International Airport carries high-value exports such as flowers and fresh vegetables, and boats carry people and goods along Lake Kivu.
Worked example 1: the break-even distance
Problem. Using the illustrative costs of Figure 1, road costs 10 000 Frw per tonne at the terminals plus 120 Frw per tonne-km; rail costs 40 000 Frw per tonne plus 60 Frw per tonne-km. Find the distance at which the two cost the same.
Solution. Set the two costs equal:
Check: road Frw; rail Frw. For trips shorter than 500 km road is cheaper; for longer trips rail is cheaper. This is one reason why long-distance railways, such as a line to the coast, matter so much to a landlocked country.
Worked example 2: choosing the cheapest mode
Problem. Water transport costs 80 000 Frw per tonne at the terminals plus 30 Frw per tonne-km. Using the road and rail costs above, find which mode is cheapest for 300 km, 800 km and 1 800 km.
Solution. Rail and water break even where , so km.
| Distance | Road (Frw per t) | Rail (Frw per t) | Water (Frw per t) | Cheapest |
|---|---|---|---|---|
| 300 km | 46 000 | 58 000 | 89 000 | Road |
| 800 km | 106 000 | 88 000 | 104 000 | Rail |
| 1 800 km | 226 000 | 148 000 | 134 000 | Water |
The pattern matches the theory: road for short trips, rail for medium distances, water for long hauls, provided a navigable route exists.
Warning
Common mistake. Saying one mode is simply "the best". The right choice depends on the goods (bulky or valuable, perishable or durable), the distance, the speed needed and the routes available. Flowers go by air because they are valuable and wilt quickly; iron ore goes by rail and ship because it is heavy and cheap.
Tip
Memory hook. "Short by road, heavy by rail, far by sea, fast by air, fluids by pipe." In an exam, give each advantage or disadvantage with a real example.
Australian National Maritime Museum: "Container — The Box That Changed The World". Watch for how one standard box moves between ships, trains and lorries without being unpacked, and why this cut the cost of trade.
Practice
Summary
Sources and credits
Photos: Mombasa Port (Stuart Price for the Kenyan Ministry of East African Affairs, Commerce and Tourism, public domain) and Transportation in water in Lake Kivu Rusizi (Divine2004, CC0), via Wikimedia Commons.
Video: "Container — The Box That Changed The World", Australian National Maritime Museum, embedded from YouTube.
Figure 1, the text, worked examples and exercises: written by Ganzaa.
