Roads and Numbers. A primer.
Okay, little educational primer here on the heels of my FedEx post. I figure if a guy that does it for a living can’t figure this stuff out some of y’all might benefit from this knowledge too.
Addresses 101
Those numbers on your mailbox weren’t delivered by a fairy. They’re calculated, and 99% of the time they make darned good sense too.
Somewhere in your area there’s what I’d call a “zero street”. Addresses to the north of it will be counting up, addresses to the south will also be counting up. If you live in a north/south street that’s why you’ve got “N” or “S” on there. It’s so the post office knows which side of that divide you live on. The same happens with east/west streets too. Heck, you can combine them into whacky combinations like “SE” and “NW” to identify which quadrant you live in.
Learn where these are. In the case of Grand Rapids, MI they are Division and Fuller. Where they intersect is the heart of our Cartesian plane.
Distance 101
Okay, so now that we know where our “zero streets” are how do we figure out were folks are? Well, addresses aren’t assigned randomly. There’s some simple math behind them. An increase of 1 in an address is about 2 meters in actual space along that axis.
In other words, if your address is 100 Main St. and the guy down the road from you is 200 Main St. you can pretty much assume that your driveways are just about 200 meters apart. The difference in the addresses is 100, multiple that by 2, and there’s your 200 meters.
You can also use this to find the offset of an address from a major street. If you’re living in an area where everything is a nice grid this works great. Roads are usually dropped at even intervals unless you’re in an old town or things are cramped.
The numerically named roads are easy. If you’re on 68th St. you are in the 6800 block. If a guy had a house right on the corner with a driveway matching up the street his address would be 6800. The distance that 68th street (6800 block) sits from 72nd street (7200 block) is: (7200-6800)* 2 meters. That’s 800 meters, or half a mile. So if you need to make a delivery to 7000 Pinewood you know that it’s exactly a quarter mile away from 68th street and 72nd street on Pinewood.
Now, when trying to figure out where a road like “Pinewood” actually is you just have to infer that from the addresses along a street that runs perpendicular from it. That’s just something you learn over time. So, if 68th St. and 72nd St. were east/west roads, and you knew that Pinewood, going north/south, was on the 1600 block, and you had an address of 1200 68th St. you’d know that the house was a quarter mile east (toward the center of town, the zero-street) of the intersection of 68th and Pinewood.
This is all stuff I learned when calculating, roughly,how far I’d ran back when I actually ran around towns.
One would think that delivery drivers would know how this, but maybe they don’t.
Now, onto the bigger scale of things:
Interstate Highways: Direction
Even numbers (I-94, I-80, etc) indicate east/west paths. Odd numbers (I-69, I-75) indicate north/south paths. Yes, they don’t always go in those cardinal directions, but for the most part you’re going one direction on them.
The exception to that rule is when the Interstate has 3 digits in it. That means you’re dealing with a short highway constructed just to deal with city traffic. If the first digit is odd you’re going to cut right through the city. I-196 here in Grand Rapids is a good example of that. If the first digit is even then you are going to go around the city. I-496 around Lansing is a good example of that one.
With a cursory glance at a map and that knowledge you can navigate your way across the entire US. It might not always give you the best route, but you will get there eventually.
Interstate Highways: Distance
The “zero point” for all interstate highways is the southwest corner of a state. If you enter a state from the east on an east/west highway and you are at exit 480 you have about 480 miles until you pop out on the other side. Likewise if you are traveling south on an interstate and you pass exit 80 you have about 80 miles until you hit the next state border.
Mile markers and exit numbers don’t walk hand-in-hand like addresses and street numbers do, but they are close enough to figured out your estimated time of arrival.
So, there you go. Road navigation 101.