You’d think that if you lived on a small cul-de-sac with only four houses, it would be simple: The house numbers would simply be one, two, three and four. But Government is not about “simple.”
Every municipality has its own system, but most follow one of two systems: continuous numbering, or hundred-block. Both systems are blocked out on grids, and both have a “baseline,” or zero point. That is the point where addresses will start, and you’ll find either 1 Main Street or 100 Main Street, depending on the system. Continuous numbering involves a formula wherein the local government first determines how many addresses are to be contained in one mile. Say the number is 1000; divide that by 5280 (the number of feet in one mile), and it equals approximately one address number every five feet.
In a hundred-block system, addresses are plotted out on a grid, where it dictates that the house at point XY is number 100, and the numbers increase sequentially within the same block. The grid is usually carefully broken down into X number of houses comprising a block, and are mapped out as the “200 block” or “400 block” of Elm Street.
Of course, add into the above formulae the further mandates of odd/even numbering based on east/west or north/south streets, and it’s enough to convince you to not choose a career in civil engineering.