Street Addresses in Suburban Chicago

At my job I have to deal with stacks of paperwork upon which Illinois residents have written their addresses. I’ve noticed that a lot of addresses in Chicago have this weird format that looks like this:

<digit><letter indicating a direction><3digits><name of road>

For example:

3N475 Cecil Adams Highway

5S118 Ed Zotti Road

9W215 Straight Dope Road

Does anybody know the signifigance of these weird addresses?


Your title says “suburban” while the OP says “Chicago”.
As far as I know, those type of addresses are limited to old rural areas where geographic indicators are part of the numbering system.

Chicago is blessed by Daniel Burnhams’ Grand Plan for ordering the city into blocks with a logical, orderly and consistent numbering logic.

I can tell almost instantly where something is in this 4 million plus city just from the addy, regardless of whether I have ever been within 5 miles of the place. And yes, you can live in this city all your life and have numerous points within the city limits you have not been within 5 miles of- thats how big it is!

Also, those weird addresses are almost exclusively in the south and southwest suburbs. I am a diehard Northsider and those addresses with the letters in them are just another indicator of the S. Sides’ moral and cultural vacuity :wink:

It’s a DuPage county thing. I’m not aware of any municipalities in suburban Cook County that do this. It’s my understanding that this is done to impose consistency on street addresses for quick location by emergency vehicles, etc.

I suppose that makes some sense, as street addresses in Cook can wildly vary as you cross suburban boundaries, even though the street names remain the same. For example, under Chicago’s numbering system, the northern edge of the city incertain areas is designated as about 7200 North. As you cross (northwards) into Park Ridge, your’re at about 1400 South under Park Ridge’s numbering system. (Numbers approximate.)

DuPage’s system is confusing to outsiders, though.

Actually, Chicago goes to 7600N (Howard St.) I live at 7405 N. so I’m a hop skip and a jump from Evanston (and lower insurance!!) ::sigh::

And to make things a little more confusing, Skokie and Lincolnwood continue Chicagos’ numbering further north and west. feh!

That kind of depends where in Chicago you are. Howard is not always the northern boundary. Much of the northern edge of Chicago is farther south. Even if you discount O’Hare and the Norridge/Harwood Heights oddity, there’s still a part of the border that runs along Higgins, at about 5600 North and (more substantially) along Devon at 6400 North. I used 7200 as a rough average.

This system is not unique to DuPage County, IL. You see addresses like that in west suburban Milwaukee as well.

The address is much simpler to understand if you break out the letter and put it in from.

So instead of
26W932 Fiddlesticks Terrace
you get
26932 W. Fiddlesticks Terrace

The direction name refers to which side the street lies on the local east-west or north-south “0” line, however one defines it. I’m pretty sure that DuPage uses the Chicago baseline grid for its unincorporated areas. So if Fiddlesticks Terrace in DuPage County, it is about 27 miles west of State Street. If you know the address range of a nearby north-south street you can easily pinpoint the location of where you are in the county.

Still, I’m not sure what makes the ##L### more desirable an addressing system than have five digit addresses.

I was under the impression that the baseline in DuPage was Ogden Ave for the N/S numbers, but I’d have to look harder into it. Actually, the one person who I know for sure has the answers is retired form where I work, so I can’t ask him. Oh well. Anyway, as was said, the address is simply an establishment off the baseline, where:
7S1430 Deerpath Road would be round about seven miles south of Ogden (Still not sure on that one. Might be North Ave, now that I’m thinking about it).

You used to mainly see them in unincorporated areas, but as development in DuPage county continues to boom (last I checked, it was the fasted growing county in the nation - neighboring Will county being the fastest) there’s less and less “unincorporated” areas left and you can often find the #N#### structure used in a lot of residental and commercial areas.

I thought Chgo had less than 3 million. When I was a kid in a grammar school in Chgo (Howland), it had over 3 million, but since then it lost many to the suburbs.

Since then, I lived in Peoria, Champaign, and Springfield, not necessary in that order. In the country, road signs indicate the section number E & W and N & S. Illinois is in the Northwest Territory, which uses the grid system of townships, ranges, and sections. A section is a mile square. They are numbered from the NE corner of the twp. You will see, for example, once you get out of Urbana or Champaign, signs reading “2S, 3W.” That means that intersection is 2 sections S of the twp line and 3 sections W. (You may substitute “miles” for sections.)

I do not know if that is what those signs refer to, as I never noticed any around Chgo, but it is easy enough to see the section lines in Chgo. They are the mile markers: Madison, Roosevelt, Cermak, etc.

Thank God I now live in Charleston. SC, that is, not Ill.