Transport and communication

Transport carries people, materials and manufactured goods from one place to another. It is an organised industry, and it adds value at every stage, by bringing raw materials to factories and goods to markets.

Distance can be measured in three ways:

• kilometres (the actual length of the route);
• time (how long the journey takes);
• cost (how much it costs to travel).

Time and cost often pull against each other when we choose how to travel: a long journey by train is cheaper but may take a day or two, while a flight takes a few hours but costs more. Your budget and your hurry decide.

Geographers draw maps with isochrones: lines joining places that take an equal time to reach from a given point. They are not real lines on the ground; like contour lines, they simply show information. Every place on the same isochrone is, say, two hours away.

A transport network is made of nodes (the meeting points of two or more routes, such as towns and junctions) and links (the routes joining them). The more links, the better connected a place is. Your home and your friend's home are two nodes (an origin and a destination); the road between them is a link; all the towns and roads of a region together make a network.

Where routes are built depends on the size and distribution of population, the location of towns, industries and raw materials, the pattern of trade, and the nature of the terrain, the climate, and the funds available to overcome obstacles.

Communication services carry words, messages, facts and ideas. For most of history a message travelled only as fast as the person, animal, boat or pigeon carrying it, so communication was really a part of transport. Then came the telegraph (messages in Morse code) and the telex. Writing first had to travel by transport, but mobile telephones and satellites have made communication independent of transport: a message now crosses the world in a second.