The Country Similarity Index attempts to quantify how similar countries are to each other relative to other countries. The index is a statistically-based way to measure this. 20% of the index is based on technology. 20% of a country’s technology score (4% of the overall Country Similarity Index score) is allocated for the country’s transportation infrastructure. The following are the aspects that were included in the calculation:
Vehicles per Capita
Wealthy countries tend to have more vehicles per capita, especially the ones that are sparsely populated and have little mass transportation infrastructure, like the top 4 countries: United States, Iceland, New Zealand, and Australia. Somalia, Bangladesh, and the Solomon Islands are among the countries with the least vehicles per capita. There are less than 5 vehicles per 1,000 people in these countries.
Wikipedia is the main source of the data:
Countries were grouped into the following categories by cars per 1,000 people:
0-100, 100-200, 200-300, 300-400, 400-500, 500-600, 600-700, 700-800, 800-900
Some countries drive on the left side of the road, while others drive on the right side of the road. This also affects whether the cars typically have the steering wheel on the left or the right in the vehicle. Myanmar is one exception. They transitioned from driving on the left to the right in 1970, but most of their vehicles are still right-hand drive vehicles, due to older vehicles and imports from Japan. Driving on the right is most common in the world. Driving on the left is usually practiced in former British colonies and a few countries adjacent to them. Japan is one of the few countries driving on the left that wasn’t influenced by the British.
Wikipedia is the main source of the data:
Countries were grouped into the following categories:
Left-Hand Traffic with Right-Side Steering Wheel
Right-Hand Traffic with Left-Side Steering Wheel
Right-Hand Traffic with Right-Side Steering Wheel
Train Ridership per Capita
Switzerland, Japan, and Denmark have by far the most train kilometers traveled per capita. European countries generally have the most train ridership. India and Kazakhstan are the highest non-European countries. Train ridership does not always correlate with wealth as the United States, Australia, and Saudi Arabia have few passenger trains. In addition, many countries do not even have passenger trains in their country.
Nation Master is the main source of the data:
Countries were categorized by the amount of passenger kilometers per capita:
Zero, 0-20, 20-40, 40-80, 80-160, 160-320, 320-640, 640-1280, 1280-2560
The typical rail gauge a country uses varies throughout the world. Even within countries the rail gauge may vary, depending on the railway. Since the rails of some train tracks are set further apart than others, they can only accommodate trains that are made for that particular width. The most common gauge is 4′-8.5″. It is primarily used in North America, Europe, the Middle East, China, and Korea. 5′-0″ gauge is used throughout the former Soviet Union, as well as Finland, Afghanistan, and Mongolia. Japan, Indonesia, Taiwan, and Southern Africa primarily use 3′-6″ gauge. Meter gauge is most commonly used in Brazil, Southeast Asia, and parts of Africa. 5′-6″ gauge is used in the Indian subcontinent, as well as Iberia, Argentina, and Chile. The rest of the rail gauges are relatively rare.
The CIA Factbook is the primary source of the data:
Countries were grouped into the following types of rail gauges:
None, 2′-0″, 2′-6″(Bosnian), 3′-0″ (Swedish), Meter, 3′-6″ (Cape), 4′-0″, 4′-8.5″ (Standard), 5′-0″ (Russian), 5′-3″ (Pennsylvania), 5′-6″ (Indian / Iberian)
Airplane Passengers per Capita
Ireland and Iceland have by far the most airplane passengers per capita. Although these countries have relatively small populations, their airports are major transit hubs. In general, the wealthiest countries have more airport traffic, due to the disposable income of their citizens. Sub-Saharan African countries tend to have the lowest amount of airport traffic. Somalia is one of the lowest, since it has over 15 million people, but only around 5,000 passengers annually.
Citypopulation.de is the main source of the data:
Countries were categorized by the number of annual airplane passengers per capita:
0-.11, .11-.22, .22-.44, .44-.88, .88-1.76, 1.76-3.52, 3.52-7.04, 7.04-14.08, 14.08-28.16
Obviously there is no one clear way to determine how similar one country is to another. How would you quantify how similar one country is to another?
Please leave any thoughts in the comments section.