Thursday, May 12, 2016


Grid systems for straight layout were extremely popular from the time people actually "designed" streets until automobiles took over. (Many of the winding streets of older cities primarily "evolved" rather than were designed in a given manner.)

Alas, while a grid pattern is popular, the scheme for naming and navigating a grid differs significantly from city to city.


In Utah, there would typically be a Main street and a Center street. (or Temple in the case of Salt Lake City.) The East-west streets south of the center or 100 South, 200 South, etc. To the north, they are North streets. The north-south streets east and west of the center are East and West respectively. This makes for a nice grid, where you can see an address of 500 N 800 E and know that it is just around the corner from 700 E 400 N. Using just the numbers, you could navigate to any destination (assuming the streets go through.) Things do get a little wonky when you go from city to city. (Does this city use the County grid or the city grid?), but it seems to work fairly well.


Seattle has taken a spin on the the Cartesian grid that sort of makes sense once you get used to it. However, just to make things confusing, there are three main alignments of the grid. Downtown, there are two grids that are aligned with the coast. This leaves them a few degrees off of north south. However, they sort of keep the common street numbering. (This causes some wonkiness in the grid that we'll get to later.)
The city is laid out in quadrants. NW, N, W, NE, E, S, SW and "central". (There is no SE in the city, but eastern King County suburbs continue the grid system with a SE)

There is a Main street in downtown Seattle. However, the central quadrant starts two blocks north (at Yesler) and goes to Denny. Why Yesler and Denny? Well, a quick look at the grid, shows the two "coast-aligned" grids are between Yesler and Denny. It makes some sense.

East of downtown, the grid turns towards a pure north-south alignment. However, the streets stay in the "central" grid. (Across Lake Washington, these would be "NE" addresses.) Most of the north-south streets in the central area are numbered. There are a few named streets west of 1st, and an occasional named street (usually an "off-grid" one) thrown in. East-West streets are all named, with an occasional naming scheme (adjacent streets will after start with the same letter.)

Numbering on East-West streets is fairly simple: between 2nd and 3rd, the addresses will range from 200-299. East of first, they range from 1 to 99.

North-South addresses are impacted by the coastal alignment. In the north south aligned areas, the block north of Yesler is the 100s. In the coast-aligned section of downtown, the addresses are based on where the street address would be in the north-south aligned area. Thus the block north of James street is the 600s, regardless of whether it is next to Yesler or 4 blocks north. It makes things a little wonky along Yesler, but keeps it consistent as you are going on most east-west streets.

South of Yesler, the "South" system starts. East-West streets are usually named and prefixed with "S" (S Atlantic) North South streets are usually numbered, and suffixed with S. (4th Ave S). Numbers start with 100s at 1st AVE S. (101 S Massachusetts). For East-West streets, they start at 100s south of Yesler. (101 3rd Ave S) West of 1st S until the Duwamish waterway, they try to keep the addresses less than 100. This can be a much longer blocks. Further south, "SW" addresses start to the west of 1st.

The West Seattle peninsula has mostly SW addresses. Most north-south streets are numbered Avenues (42nd Ave SW), while East-West streets are typically named until you get further south (SW Alaska St.) The streets will typically keep the same name from SW to S quadrants (even though very few of these go through.)

North of Denny, the West, North and East addresses start. All of these are north-south aligned. The north addresses are generally a continuation of the coast-aligned grid.

The East grid is a little weird. All East-West streets north of Yesler are prefixed with East (E Yesler) However, the north-south streets do not have the suffix. The change to E seems to occur where the street changes from coastal to compas alignment. (Unless it is an odd street like Yesler or Madison that doesn't change alignment. (These both change at Broadway.)

Eastlake is also a border between "North/central" and East - except when it isn't. Basically, Eastlake is the border between East and North until it Runs into Fairview, in which case everything is East. (It is almost Lake Union as the border, but not quite.)

North addresses start at Queen Anne Ave (which is "0"). Many of the North South streets are numbered Avenues, up to 9th Ave N, and which point they have names over to Eastlake. The East West Streets are typically named and have no prefix or suffix. Street names continue from the North quandrant to the east quandrant, even though Lake Union is in the way.

West of Queen Anne Ave, the West addresses begin. The streets are typically named (W Garfield St) and continue the E and north naming. The Avenues are typically numbered (15th Ave W) and start on their own. (The only Avenues that continue from central or the Eliot and Western diagonals.)

Now we have a grid that covers the city south of the ship canal. North of the canal, we tag a "N" onto the East and West quadrants. Thus, E becomes northeast and W becomes northwest. They look like they continue the same grid. The Ballard bridge is the only street that connects Northwest to West. On it 15th Ave W changes to 15th Ave NW. When going down 3rd Ave W in Queen Anne, you can also see 3rd Ave NW rise in the distance, so it seems to be pretty consistent.

The northeast quadrant seems to be more-or-less aligned, but there is no street that makes a direct shot. The university bridge is diagonal and the Montlake bridge approaches have some curves.

North is just weird. South of the ship canal, north addresses are mostly south and west of lake union, with a tiny bit east of the lake. These more or less continue the "central" grid. (More or less, because the central grid switches from offset to north south at Denny - right where north starts.) North of the ship canal and lake union the north grid continues. Only this grid is totally different. The streets all have different names. (the southern north are mostly numbered avenues, while the northern ones are all named. The grid is also offset. 4th Ave. N continues on to the Fremont bridge where it becomes Fremont. The street is basically straight, yet north of the Canal, Fremont is 700 N, while south of the canal 4th is 400 N. This can be somewhat explained by Queen Anne Avenue. South of the canal it is "0", with 1st Ave W and 1st Ave N to either side. Norther of the canal. 1st Ave W is the divider, with 101 N immediately to the east. That explains some of the offset, but not quite all of it. Aurora Ave N is the one street that goes through both "north" sections. However, it has some curves and is tied more closely to being a "highway" than its actual location. It is mostly around 900 or 1000 north of the ship canal, and around 5th or 6th south of the canal.

For east-west streets, there are surprisingly few streets that span uninterrupted from NW to N to NE, even though this continues the same grid. The shape of the ship canal means 38th is the first street that could possibly span the quadrants. However, Aurora blocks the way starting at 39th, with only crossings at 41st, 46th and 50th. 41st gets stuck in some Fremont hills. You can almost say 46th goes through if you don't mind some stairs, a some pedestrian short cuts and a zag to market. 50th also comes tantalizingly close, but requires a quick jog to Market. From 50th to 78th, Woodland Park and Green Lake block the way. Finally we reach 80th, the first street that legitimately makes it through from NW to NE. North of 80th, the freeway blocks the way to NE. 92nd crosses the freeway and does span the distance from NW to NE (though a few blocks are offset.) The freeway takes a job to the east, north of 115th. However, cemeteries block 110th to 125th. Haller lake blocks 125th, leaving 130th as the next street that makes it through. 145th at the city limits is the only other one that makes it through in the city of Seattle. (At the county line, 205th also goes through. However, it is also Snohomish county 244th SW, which is a while different can of worms.)

Another curious part is the number of streets. 101 N 80th would be across the street from 101 NW 80th, but over a mile away from 101 NE 80th.

Routes connecting southwest to south are even rarer. This is a function of the Duwamish serving as a barrier, leaving Spokane Street as the only significant street within the city limits that spans SW to S.

From north through central to south, 1st is the champion. 5th is in second, for making it a good distance in both north and south. Other streets make appearances in both north and south, but don't go more than a few blocks.

Temple, Texas

The grid starts near the railroad tracks at Main and Central. The grid is not quite north south. It is also not quite aligned with the railroad tracks. However, it does look like a small section of the railroad track near downtown is almost aligned with the grid. Maybe this was the original alignment? But the way the grid grew out the railroad tracks end up splicing the city and seemingly random angles.

In the grid, Avenues, run roughly east-west. Main street is 0. The next block East of main starts E 100, while the block west of Main starts West 100. Similarly Streets run North-South, with north addresses north of Central and South addresses to the south. So far, all is fairly normal.

It is in the naming of the streets that things start to get a little crazy. Avenues south of Central start with Avenue A, and continue to Avenue Z. (After Z, the streets become random, but by the then, the grid is for the most part gone.) North of Central, they are named alphabetically from Adams to Zenith (Q seems to be missing, but up there the grid is already starting to peter out.) Ok, this part makes sense. It is the streets that get really weird. First street is west of Main. West of first is third. And the streets continue with only odd streets to the west. However, the street numbering scheme stays relatively constant.


Major streets are every mile. Minor streets are every half mile. There are eight streets to a block. Streets keep their name through the length of the city (and beyond.) Numbers start at Madison and State in the loop and go in the compass directions, with 100 units to the block. It is beautifully simple - except when it is not. Downtown is one catch. Lots of the streets are "major streets" downtown, but we can deal with that. The other problem is the south of downtown numbering. There are 12 streets to a mile for the first mile, 10 for the second and 9 from the third. And of course, these streets are the ones that actually use numbers rather than names. So, the adresses follow the numbers to be consistent. (However, the first 12 blocks are named, so it is just weird.)
Street names tend to be somewhat willy-nilly. Avenues are often north-south, though not always. Streets are usually east west, unless they are north-south. Parkways and roads are also mixed in there. Boulevard usually means it is a wide street with a manicured median that is part of the boulevard system. (Though some of the boulevards can look just like a regular road.) It's safe not to assume to much about the road type.
There is also the little matter of needing more streets. Remember how Seattle streets are 20 to a mile? Well, Chicago is not that much more spread out. To compensate, there are a lot of smaller streets mixed in there. These smaller streets are often treated as block bisectors, dividing the block at the 50. On the south side, with numbered streets, there will typically be a "place" in between the streets. This can make the numbering a much less exact science. (For example, there are 5 evenly spaced blocks in part of the area between 51st and 55th in Hyde Park. 54th place is between 54th and 55th. The numbering schemes adheres to the street name, thus the 5400s consume more space than the 5300s or 5200s.)

San Francisco Bay Area

San Francisco has a downtown grid aligned with Market. Most of the city has a roughly north-south grid - except where the grid decides to align with the diagonal Mission. This layout seems to have caught on down the peninsula. Most of the cities are laid out parallel and perpendicular to the Caltrain tracks and El Camino Real. Redwood City decided that since it was the county seat, it also needed a north-south grid. So, the two grids meet in downtown. Further down in Silicon Valley, you start to see the grid "break" around the Los Altos/Sunnyvale area. The old train-oriented communities have a grid aligned with the railroad. Further out the former farm regions are all north/south.

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