Which of the following countries has the highest density of railway network?
- (a)Canada
- (b)U.S.A.
- (c)Russia
- (d)India
Correct — B, U.S.A.
Density of a network is length divided by the area it covers, so the comparison is route kilometres against the size of the country, not route kilometres on their own.
The U.S.A. has roughly 220,000 route km, the longest national railway network in the world, inside about 9.8 million sq km. That is close to 22 route km for every 1,000 sq km.
India is the nearest challenger of the four: close to 70,000 route km compressed into about 3.29 million sq km, roughly 21 per 1,000 sq km. Russia and Canada each work out near 5.
Carry away that a network can be long and still be thin, because area sits in the denominator.
- (a)Canada — Canada has roughly 49,000 route km spread across about 10 million sq km, which is around 5 route km per 1,000 sq km — the lowest ratio of the four.
Its vast territory is what makes it tempting, but territory enlarges the denominator and pushes density down.
Canada is the right answer to which of these four has the most railway route length per head of population: roughly 49,000 km serving a population of just over 40 million works out far above the American, Russian or Indian figure.
- (c)Russia — Russia's roughly 92,000 route km make it the second longest network of the four, ahead of India. Divide by about 17.1 million sq km — the largest national territory — and the ratio falls to about 5 route km per 1,000 sq km.
Russia is the right answer to the world's longest continuous railway line, the Trans-Siberian, which runs about 9,289 km from Moscow to Vladivostok. The length of one line, like the length of one network, is not the density of a network.
- (d)India — India comes closest to the keyed option, and for the right reason: close to 70,000 route km inside about 3.29 million sq km gives roughly 21 route km per 1,000 sq km, because a large network sits in a much smaller country.
It still lands below the American ratio of about 22, and its network is far shorter in absolute terms.
India is the right answer to which of these four carries the most railway passengers, a traffic count that says nothing about how much line each 1,000 sq km holds.
Network density measures how much line a territory has, not how much line exists. It is route length divided by area, usually written as kilometres per 1,000 sq km.
Because it is a ratio, both numbers move it. Adding route length raises it; spreading the same route length over a bigger territory lowers it.
The same network transplanted into a smaller country would score higher without a single kilometre being laid.
Density belongs to a family of ratio measures — population density, road density, physiological density — that all answer the question 'how much per unit of area'.
In transport geography the distinction earns its keep: absolute network length tracks how big and how industrialised a country is, while density tracks how thoroughly that country is served. Ranking on the wrong one reverses the order, as Russia and India show here.
A density superlative also holds only against the list offered. Measured per unit of area, compact industrial countries such as Belgium, Czechia and Germany stand well above all four of these.
- The United States has the world's longest national railway network, roughly 220,000 route kilometres.
- Over an area of about 9.8 million sq km, that is close to 22 route km per 1,000 sq km.
- India's network of close to 70,000 route km in about 3.29 million sq km works out near 21 route km per 1,000 sq km.
- Russia's roughly 92,000 route km lie in about 17.1 million sq km, giving about 5 route km per 1,000 sq km.
- Canada's roughly 49,000 route km lie in about 10 million sq km, also about 5 route km per 1,000 sq km.
- Russia has the second longest network of these four and the lowest density along with Canada, because its territory is the largest.
- The Trans-Siberian Railway runs about 9,289 km from Moscow to Vladivostok on the Pacific coast.
- Route kilometres count a line once, while running-track and total-track kilometres count parallel tracks separately and give larger figures for the same network.
Density is the ratio, not the total: Russia's network is longer than India's yet lies far thinner on the ground.
- Reading 'density' as 'total length'. Russia's network is longer than India's and thinner than India's, so the two readings give opposite answers.
- Assuming the largest country must have the densest network. Area is the denominator, so extra territory drives the ratio down.
- Carrying 'the U.S.A. is the densest' outside this list of four. Measured per unit of area, several small European countries stand well above it.
- Switching denominators midway. Change from area to population and the order of these four changes with it, Canada moving to the top.
- Computing density from track kilometres for one country and route kilometres for another, which inflates whichever country is measured by track.
The idea arrives as a superlative over a short list — four countries, four states, four districts — with a ratio word planted in the stem: highest density of railway network, of road, of population.
The work is to identify the numerator and the denominator that word implies, then check whether the option that looks biggest in raw terms survives the division.
It also turns up inside statement-based items, where one line claims a network is the largest in the world and another gives a density ranking, and each has to be settled separately.
UPSC_2002_GS1_Q942002The same vocabulary turned on transport: one of its lines ranks states by density of surface road, which is this ratio applied to a road network, and another asserts that the Indian railway system is the largest in the world — a claim the figures behind this item run against, since the United States network is the longer one. What differs is the format and the scale: a multi-statement item about India's own transport system, not a single superlative across four large countries.
UPSC_2009_GS1_Q472009Identical shape — a short list of countries, a 'highest density' superlative and one division to perform. What differs is what is being divided and where: people per sq km among South Asian neighbours, against railway route kilometres per sq km across four of the world's largest countries.
UKPSC_2024_PRE_GSI_Q182024Density again in an earlier UKPSC prelims paper, but pushed down to the districts of Uttarakhand and set beside sex ratio and religious composition in a statement-verification format. Shared: a density superlative that has to be settled against published figures. Different: Census population data at district level rather than comparative railway geography.
- practice — not a real PYQ
The density of a railway network is best expressed as:
- (a)the total route length of the network
- (b)route length per 1,000 sq km of area
- (c)the number of trains run per day
- (d)the number of passengers carried per year
Answerb — Density is a ratio of network length to the area served, so route length per 1,000 sq km is the standard expression.Option (a) is the network's absolute size, which tells you nothing about how thoroughly an area is covered. Options (c) and (d) measure traffic moving on the network rather than how much line exists per unit of area.
- practice — not a real PYQ
Which one of the following countries has the longest railway network in terms of total route length?
- (a)India
- (b)Russia
- (c)U.S.A.
- (d)Canada
Answerc — The United States network, roughly 220,000 route km, is the longest national railway network in the world.Among the others, Russia follows at roughly 92,000 km, India at close to 70,000 km and Canada at roughly 49,000 km. Each is well short of the American figure, so the ordering leaves only one defensible choice.
- practice — not a real PYQ
The Trans-Siberian Railway runs from Moscow to:
- (a)Vladivostok
- (b)Murmansk
- (c)Volgograd
- (d)Novosibirsk
Answera — The line runs about 9,289 km eastward from Moscow to Vladivostok on the Pacific coast.Novosibirsk lies on the route but is an intermediate city in Siberia, not the eastern terminus. Murmansk sits on the Arctic coast in the north-west and Volgograd on the Volga in the south-west, each reached by other lines.
- practice — not a real PYQ
Country X has 90,000 km of railway route in an area of 18 million sq km. Country Y has 60,000 km of railway route in an area of 3 million sq km. Which one of the following statements is correct?
- (a)X has both the longer network and the higher network density
- (b)Y has the longer network but the lower network density
- (c)X has the longer network while Y has the higher network density
- (d)The two countries have the same network density
Answerc — X works out at 5 route km per 1,000 sq km and Y at 20, while X's 90,000 km exceeds Y's 60,000 km. So the longer network and the denser network belong to different countries.Option (a) credits X with the higher density, which the division contradicts. Option (b) reverses both halves, since Y's network is the shorter one. Option (d) fails because the two ratios differ fourfold.