Eli5, why do roads have numbers assigned to them as well as names?


My kid asked me this question and I didn’t have a good quick answer. Also, I’m not referring to the US Interstate highway system. I am referring to the state and county level.

Any insight is much appreciated!

In: 3

This is an interesting question and I had to look it up. In the US at least, the highways started being numbered in 1925. This is well before the inception of the Interstate system in the 50’s. I found the original document where the Joint Board on Interstate Highways recommended standardizing the major US highways. https://en.wikisource.org/wiki/Report_of_Joint_Board_on_Interstate_Highways_October_30,_1925

The basic reason is to set them apart from regular roads and to show their significance.

> “This Association hereby requests the Secretary of Agriculture, in cooperation with the several States to undertake immediately the selection and designation of a comprehensive system of through interstate routes and to devise a comprehensive and uniform scheme for designating such routes in such a manner as to give them a conspicuous place among the highways of the country as roads of interstate and national significance.”

To identify them. There aren’t enough names. Names of roads and streets are commonly repeated. Numbers can all be different in a structured way. The numbers can reduce confusion and be related to each other. This is done all over the world.

In the U.S. our highways have numbers to tell you which direction your going it even are north and south and odds are eat and west, i may have that backwards but that is why the numbers. As for names it depends on which names you mean, some were historical figures, sometimes its named after something in your county, city, or state. I have no idea who or how they decide what streets get what names. Hopefully someone here will.

Well, everything has to have a name, and it is usually the creator of that thing, that gets to name it. So, to look at how roads get their name, we start with how those roads are created.

Large road systems that are designed top-down, via centralized planning, tend to use numbering system as names. There is usually a system to how theses numbers are assigned. This method of naming roads is efficient and rational, good if it’s a big project that involve many people, and take many years to complete.

On the other hand, roads that are built bottom up, by the individuals, private companies, or local municipalities for their own use, tend to get named by their builder, and thus are given more meaningful names, kind of like how parents name their babies.

If a centrally planned road system make use of existing roads, then that section of road would have 2 names. For example, both the original name Pine St. and also Highway 17.

Lastly, roads can get re-named (or in this case, have a name added) after they are built. For example, people can rename a stretch of highway so-and-so memorial highway to memorialize a person.

The city names the streets in its jurisdiction, even if they also have a U.S. Route or state highway number.

In large parts of the U.S., the streets were there first, back to horse and buggy days. The highways came later, and connected to the busier streets that already had names.