Transport network

Topic: World Transport and Communication · NCERT: Class 12, Ch 6 "Tertiary and Quaternary Activities"; Class 12, Ch 7 "Transport and Communication"

Meaning

A transport network is the pattern formed when several places, called nodes, are joined to each other by routes, called links. The more links a network has, the better its places are joined and the easier they are to reach. So the shape of a network shows which regions are well served and which are cut off.

Explanation

Parts of a network: nodes and links

• Node: a meeting point of two or more routes. A node can also be:
• a starting point (origin);
• an end point (destination);
• any large town along a route.

• Examples: a railway junction, a port, an airport hub, a road crossing.

• Link: any road, railway, air route or sea route that joins two nodes.

• The network is only the pattern of routes (the arteries). A full transport system also needs vehicles (trucks, trains, ships, aircraft) and organisation (timetables, ports, traffic control, maintenance).

Connectivity and accessibility

• Connectivity: how well the nodes are joined to each other.
• Accessibility: how easily a place can be reached.
• More links mean better connectivity:
• each new link opens another path between nodes;
• so more places can be reached, and by more than one path;

• if one route is blocked, traffic can take another.

• Few links mean weak connectivity:

• some places have only one way in;
• one broken bridge or blocked pass can cut a place off.

Measuring a network: the beta index (beyond NCERT)

• Beta index (β) = number of links ÷ number of nodes.

β value	Network type	Meaning
Less than 1	Tree-like or broken network	Few links; some places have only one way in
About 1	Simple network with one circuit (a closed loop)	Basic loop
More than 1	Complex, well-joined network	Many other routes to choose from

• Worked example:
• 5 towns joined by 4 roads → β = 4 ÷ 5 = 0.8 (poorly connected).
• Add 3 roads, so there are 7 links → β = 7 ÷ 5 = 1.4 (well connected).

What decides how dense a network is (Class 12, Ch 6)

• Demand: bigger and denser populations need more movement, so they need more links.
• Where routes go depends on:
• Location of settlements: links join cities and villages.
• Location of industries and raw materials: links join mines to mills and mills to markets.
• Pattern of trade: links follow the flow of goods between regions and countries.
• Relief (shape of the land): mountains, rivers and marshes make links costly or push them off a straight line. Plains make links cheap.
• Climate: snow, monsoon floods, desert heat and frozen seas all affect routes.
• Funds: tunnels, bridges, canals and cuttings cost a lot. Richer economies build denser networks.

Where it occurs

• Dense networks with a high β are found in industrial regions:
• North-west Europe;

• North-eastern USA.

• Sparse networks with a low β are found where relief and climate make building routes hard:

• deserts;
• high mountains;

• thick forests.

• Canals as new links in the world sea network:

• Suez Canal (opened 1869), Egypt: joins the Mediterranean Sea and the Red Sea. Ships between Europe and Asia (including India) no longer go round the Cape of Good Hope in southern Africa.

• Panama Canal (opened 1914), Panama: joins the Atlantic and Pacific Oceans. Ships no longer go round the tip of South America.

• New corridors that add links to the network: the INSTC (International North–South Transport Corridor) and the IMEC (India–Middle East–Europe Economic Corridor) aim to cut the time and cost of moving goods between India and Russia or Europe.

• India: planning the network as one system:
• PM GatiShakti National Master Plan (a digital master plan for multimodal connectivity, meaning several modes joined together) was launched on 13 October 2021. The Union Cabinet approved it on 21 October 2021 [2][3].
• It ends "silos", where each ministry planned alone. Ministries and states now plan together to close gaps in multimodal and last-mile links [2].
• Its seven engines are Railways, Roads, Ports, Waterways, Airports, Mass Transport and Logistics Infrastructure [2].

Don't confuse with

• Node vs link: a node is a point (a junction, port, airport hub or town). A link is the route that joins two nodes. In the beta index, links go on top and nodes go below.
• Connectivity vs accessibility: connectivity describes the whole network (how well the nodes are joined to each other). Accessibility describes one place (how easily it can be reached).
• Transport network vs transport system: the network is only the pattern of routes. A transport system has three parts: arteries (routes), vehicles and organisation.
• Transport network vs isochrone: a network shows routes and junctions. An isochrone is a line on a map that joins places reached in the same time from one point. Isochrones stretch out along the fast links of a network.

Prelims Hooks

• Node = meeting point of two or more routes, an origin, a destination or a large town on a route. Link = a road, rail, air or sea route joining two nodes.
• Beta index = links ÷ nodes (not nodes ÷ links). A trap option often reverses the order.
• β less than 1 → tree-like or broken network. β about 1 → one closed loop. β more than 1 → complex, well-connected network.
• 5 nodes and 4 links → β = 0.8. 5 nodes and 7 links → β = 1.4.
• Dense, high-β networks: north-west Europe and north-eastern USA. Sparse, low-β networks: deserts, high mountains and thick forests.
• PM GatiShakti NMP: launched 13 October 2021, with 7 engines for multimodal connectivity [2].

Mains Points

• Network density and regional inequality (GS-I):
• Industrial plains have dense networks with a high beta index. Mountains, deserts and forests have sparse ones.
• The causes are relief, climate, population (demand) and the funds available.
• Sparse networks mean poor accessibility. Places with only one way in are cut off by a single landslide or flood.

• Policy answers include tunnels, bridges and last-mile links. Isochrone maps help decide where to put hospitals and schools fairly.

• Integrated network planning in India (GS-III infrastructure):

• PM GatiShakti (2021) joins seven modes into one planned network and ends ministries planning alone [2].
• The National Logistics Policy (17 September 2022) aims to bring logistics costs down to global levels and to place India in the top 25 of the Logistics Performance Index (the World Bank's ranking of how easily goods move through a country) by 2030 [4].
• ULIP (Unified Logistics Interface Platform) puts the transport sector's digital services on a single portal [4].

• The aim is to cut logistics cost from about 13–14% of GDP to a single-digit figure [5]. This would make Indian exports more competitive.

• New links redraw trade routes (GS-I/GS-III):

• The Suez (1869) and Panama (1914) canals added key links to the world sea network. They cut km, time and cost distance.
• The INSTC and IMEC follow the same idea. They add links that cut the time and cost of moving goods between India and Europe or Russia.

Related concepts

• Transport
• Node
• Link
• Transport distance
• Isochrone
• Factors affecting transport
• Modes of transport
• Complementarity of transport modes

Read more

• Transport, networks and distance: the basic ideas