There's a system to how addresses are lain out that isn't really obvious, but once you're aware of it, makes finding your way to a specific street address something you can do mostly-deterministically.
Disclaimer #1: I found a report dated 1950 by the American Society of Planning Officials that broadly mirrors much of what I've written here, so I feel comfortable saying that this isn't just California, which is where most of my experience is. But this may not apply outside the US.
Disclaimer #2: These are general rules and there are definitely places that don't follow them and individual addresses that are exceptions to them. Consider this a 90% solution.
1. Addresses are assigned on a street in blocks of 100, in numerical order
At an intersection, you'll often find one or two street name signs on a pole, with each sign aligned with the street it names and bearing a block designation like “300 →”. The block in the direction of that arrow is “the 300 block”, and its addresses are no less than 300 and less than 400.
Note: A block is one length of street from one cross street to the next without interruption (except alleys). “The 300 block” indicates the start and end of the range for that block; it does not mean 100 addresses from 300 to 399. Skipping addresses (e.g., 371 simply doesn't exist) is very common. But if an address doesn't exist, you're probably not trying to find it.
Whether the first block is the 100 block or the 000 block varies. San Francisco uses the 000 block (first assignable address may be as low as 1) but plenty of places start at 100 or even 1000.
2. Blocks are assigned from one end of the street
A fun demonstration of this is here in San Francisco, where Market runs diagonally and is the end of pretty much every street that runs up to it. (Even Van Ness, which intersects Market, is “Van Ness” going north and “South Van Ness” going south.)
This means that, say, the 000 block of O'Farrell is one block south (all of these are west-east streets) of the 100 block of Geary, which is one block south of the 200 block of Post, which is one block south of the 300 block of Sutter, etc.—because each of those streets has its 000 block at (that street) and Market, which runs in a southwest/northeast direction. All the 000 blocks are stacked up diagonally against Market, where the starting end of each west-east street is.
But that's an exception; most cities have more-regular rectilinear grids and the 100 block of any given street is usually aligned with the 100 block of each of the streets on either side of it.
More generally, this is often the distinction between “N Elm St” and “S Elm St”, as in the Van Ness example above (although Van Ness is just Van Ness, not North Van Ness). The first block of N Elm St is usually immediately to the north of the first block of S Elm St; N Elm St's blocks ascend northward while S Elm St's blocks ascend southward.
3. Addresses are even on one side of the street, odd on the other side
Walk down a street. Let's say you come upon 512 Elm St. Look across the street: There's 511 or 513, most likely.
It's not always one-to-one for a variety of reasons, so it might be 519 or something, but it'll still most likely be even on one side and odd on the other.
(And the same block, so you might see 519 across the street but you usually won't see, like, 619. It'll still be something in the 500 range, because “the 500 block” applies to both sides of the street equally.)
Putting it all together: How to find an address
First, find the street. In the old days we used to use paper maps to do this. These days you'll probably get led to the vicinity of your destination by your maps app. Or you might know where that street is and be able to get to at least the street in question unassisted.
So let's say you're looking for 1789 Brooks Rd. You've managed to make your way to the corner of Brooks and Stones, and you see that the corner sign says:
BROOKS
← 1600
Now, the arrow doesn't necessarily mean much. It just means “that's the 1600 block”. But you're within about two blocks of your destination. You know where the 1600 block is, and you know that the 1700 block is next to it in one direction or the other.
You have a few options:
- Look at the nearest block that isn't 1600. Go in the opposite direction from the arrow (possibly the block you're on), and look for an address number. Any visible address will do. You're looking to answer one simple question: Is this the 1500 block, or the 1700 block?
- Look at the 1600 block and figure out its direction. Look for any two addresses on that block (preferably on the same side of the street as each other). If you see an address and then a higher address, you're going the right way (toward 1700). If you see a lower address, you're going the wrong way (toward 1500) and should turn around.
- Walk a block and see where you ended up. If you walk past the 1600 block, you'll either end up at the 1500 block or the 1700 block. This may or may not be the easiest way depending on the prevalence of street signs (SF is notorious for having very few street signs) and visible addresses. If you find the 1500 block, turn around and walk back the way you came.
One way or another, you'll find the 1700 block. Now, start looking for addresses so you can identify which is the odds side and which is the evens side. You're looking for 1789, so if you're on the evens side, cross the street (here in California you can do that legally at any time as long as it's safe).
From here it's largely process of elimination. Ah, here's 1753. Here's 1777. Here's 1795—oops, too far. Here's 1791; 1789 is probably the one next to it, even if it's not explicitly marked.
Which reminds me of one more bonus tip:
4. Address numbers are often painted on the curb
You know who really needs to find address numbers quickly with a minimum of searching and squinting and wrong turns? Firefighters.
For their benefit, it's really common—I don't know whether it's legally required—for there to be address numbers painted on the curb in front of each address, where firefighters, delivery drivers, and anyone else can easily see it from a vehicle (as long as there isn't street parking). So sometimes a shortcut to finding the exact address—rather than having to count houses from one whose number is more visible—is to look at the numbers painted on the curb.