Who determines the roads?

Driving on many roads yesterday I noticed a few things and formed a few questions…

Why do even-numbered interstates go east to west and odd-numbered go north to south? Who decided on this?

Who names roads? I saw a road called “The 12th four way”, and another called “Snapfinger Rd”! It sounds like they ran out of ideas!

I notice that exits are numbered outward from a source (in Georgia its from Atlanta…is it the capital in all states?)…How are the state highways number determined?

Nope - Georgia used to number it’s exits in straight numerical order, with, on a north-south interstate the southernmost being #1, the next being #2 and so on.

Now, they number them by mile marker, with North/South interstates beginning at the southern end of the state and East/West interstates at the western border - as far as I know, most states use this system.
Some general information on interstate numbers is available here.

The US Interstate System was created after WWII during the Eisenhower admin and was very systematic and planned. Here is some general info about it:

I know a number of “highway geeks”, including my dad who was a young man in the 50s and knows all about what highway goes where, thru what towns, when it was built, etc. etc. Here is an example of a highway geek website:


In most jurisdictions when a new road is created, in a new subdivision for example, the developer submits a name to the city or county and if they have no objections they approve the requested name.

Who actually has approval rights will vary from area to area.

I recently purchased a lot in a rural subdivision and called the Post Office to find the address. Turns out that addresses are assigned by the local “911” emergency dispatch office.

This site is a good highway geek site. Ever wonder what’s at the end of the interstate? You’ll find pictures here.

Thanks for that site, MSU 1978. It just might turn ME into a highway geek! I am going to have to go out and take some photos of the hidden interstates of DC to post there.

Glad to be of service, Betty. If you want to see the ends of the US routes, then this site might be of interest, too.

GaryM’s explanation is directly on point.

Town councils–and, in unincorporated areas, county councils–also name-- or rename–streets on their own initiative. In St. Louis, for instance, there is a James “Cool Papa” Bell Avenue, in recognition of the block on which the legendary Negro League baseball player lived.

In a great many places suburban streets have names such as “Mary” or “William” which turn out to be the name of a developer’s child or grandchild.

In one of the suburbs of St. Louis there is an Easy Street. According to legend, a person who was planning to move into a home on that street once construction on the subdivision was completed put a sign up as a joke and an employee of the construction company, thinking it was for real, ordered street signs to be made up.

The Dwight D. Eisenhower National System of Interstate and Defense Highways Straight Dope.