In his seminal book, Energy and Equity, Ivan Illich proposed an ideal traveling speed for humans of ten miles per hour. Automobiles, he said, were capable of speeds that made the world blur, adversely affecting our physical, mental and spiritual health.
Horses trot along at an average pace of ten miles per hour.
Bicycles pedaled easily and comfortably, at a non-racing speed, average between 10 and 11 miles per hour.
And life taken at this pace can be truly taken in, and absorbed and experienced.
Which is the primary reason I love riding a bicycle for transportation. Because if you see something interesting, you can actually pull over, stop, and take a closer look if you want, without risking a high-speed accident on a freeway (as you might in a car going 60 miles an hour).
And seeing the world -- really seeing it and taking it in -- is part of the point of riding a bicycle.