I've come across an apocryphal tale in the U.S. west describing why certain towns and cities have main streets that are the width required to fully turn a wagon pulled by x number of horses.

Likewise, in the Canadian House Of Parliament, the width between the Prime Minister's desk and that of the Leader Of The Opposition is said to be that of two swords raised, tip to tip, based on the British House Of Commons tradition that they must remain ''two swords and one inch apart.''