Tag Archives: mapping LA

How Does Your Grid Grow?

Every city has an underlying historical layout that shapes growth. For example, New York is dominated by a continuous grid of avenues and streets, first deployed in Manhattan in the early 1800s, then repeated again and again in Brooklyn and Queens. In Boston, development is shaped around “squares” (which might more properly be called “crossroads”), along the major roads connecting the squares, and then into local grids of varying regularity.

In Los Angeles, development is shaped by a grid of north-south and east-west arterial roads, generally on half-mile spacing. The grid is somewhat distorted by topography and historic land grants, such as the old pueblos and ranchos. While some areas have New York-style continuous grids in between the arterials, much of the city has features such as irregular grids, curvilinear streets, and jogs in the grid, all of which discourage through traffic and transit. This reinforces the importance of the arterials.

Navigating a city requires forming an internal map of this structure – where the roads go, and how well they do it. For example, if you spend a lot of time in the Inland Empire, you probably know Milliken, Haven, and Archibald, and which one isn’t continuous around Ontario Airport. If you live on the Westside, you know Pico, Olympic, Santa Monica, and Wilshire, and which ones will ruin your bus ride in the afternoon. In Boston, you might know that Somerville Ave takes you between Porter Square and Union Square, while Cambridge and Washington Streets take you between Union Square (Allston) and Oak Square. On the other hand, Manhattan’s continuous grid devalues knowledge about the east-west streets; you’re better off knowing the major streets and the few areas where the grid is disrupted, like Morningside Park.

When I started posting about north-south transit on the Westside, I found that I didn’t really like any of the readily available maps. For my eye, Google Earth and Maps are too busy, while highly stylized maps, like LA Metro’s system map, are too distorted. I wanted a map that was roughly geographically accurate, but stripped down enough to show the underlying structure. So I made my own map of the mile-spaced arterials, scaling distances in Google Earth and drafting in CAD. The original plan was to just do the Valley and the LA Basin, but I ended up doing all five LA area counties (LA, Orange, San Bernardino, Riverside, & Ventura).

This exercise was very revealing because it shows how much editorializing is involved in mapmaking. While maps are often presented as unbiased fact, the content is strongly influenced by the personal, social, and cultural background of the person making the map. Even on this map, which only includes streets, we must decide which streets are important enough to be included. As suburbia faded to desert in the Antelope Valley and farms in the Coachella Valley, I kept putting in the arterials as long as they were paved. Do Avenue A and Hayes (named for Rutherford B Hayes in one of the most extensive presidential street grids you’ll find) really belong on the map? You tell me.

This map only includes arterial roads. There are no freeways and no rail lines. Yet if you know LA’s geography, you can probably pick out many regions by their arterial structure – the regular grids of the Valley, the LA Basin, northern Orange County, and the Coachella Valley; the growth-boundary-stunted grid of Ventura County; the irregular layout of hilly areas like the Santa Clarita Valley and southern Orange County; the established grid of the older San Bernardino County cities and nascent grid of the newer Riverside County cites; the ill-defined edges of growth in the High Desert. You’ll also see features from where there aren’t roads, like the immense expanse of the San Gabriel Mountains. And finally, you might see things you didn’t realize before, like the oddly distorted north-south arterials between Main and Cherry in the LA Basin.

Despite showing only arterial roads, the map can be read in many ways depending on your point of view. Does the anticipatory grid in the Antelope Valley portend endless sprawl, or room for opportunity? Or is the lonely view along 200th Street E to Hi Vista that and nothing more? What about golf courses and subdivisions creeping southeast into the farms of the Coachella Valley?

Anyway, enjoy. Click to embiggen. . .