A person on a bicycle is the most efficient form of travel on the planet. No other living creature expends so little energy related to the distance traveled. Bicycles are able to convert about 90% of effort into forward kinetic energy. It takes about 3x amount the amount of energy to walk any particular distance than it does to bike it.

The bicycle is the most widely utilized form of human transportation in the world. Worldwide, there are about twice as many bicycles as there are cars.

Bicycles are inherently stable when riding. Even riderless bicycles are stable if given enough forward velocity. If a riderless bike is struck from the side, it will usually straighten and stabilize. There are about 25 different variables that explain the physics of a bicycle’s movement. Two primary reasons that a riderless bike is stable are the gyroscope effect and the design of the front fork and wheel:

Cycling has become more popular in the U.S. over time:

There are about 100 million bicycles in the U.S. which is about one bike for every three people (about 32%). In terms of top bicycling countries, here’s the top 10 on a per capita basis:

Due to China’s huge population, even though they are ranked 10th on a per capita basis, about half of all bicycles in the world are in China.

Incongruously, the amount of cycling in a country is negatively correlated with the number of cyclists killed:

Why are there less fatalities in countries with more cyclists? A primary reason is safety in numbers: “the ‘safety in numbers’ phenomenon is rather simple to grasp – more cyclists means more awareness among motorists. A lone cyclist in a traffic-choked urban area is far more likely to experience an accident and injury.” Source.