Or megalopoleis for the pendantic.

I remember reading Neuromancer and being entranced by Gibson’s vision of the Sprawl, or more verbosely, the Boston-Atlanta Metropolitan Axis which can be acronymized as BAMA. This is really not that far off, since BosWash (which includes Boston, NYC, and Washington D.C.) has been considered a megalopolis for some time now.

So I thought of what the equivalent would be on the West Coast and came up with SeaSanD, which is basically the I-5 corridor, therefore including Seattle, Portland, the S.F. Bay Area, L.A., and San Diego. But ignoring international boundaries, you could really go from Tijuana to Vancouver, B.C. (Isn’t it random that both ends of the I-5 leave the U.S. and enter a province abbreviated as B.C.? Baja California in Mexico. British Columbia in Canada.)

San Diego as the southern nucleus of a West Coast megalopolis is kind of misleading. As of 2005, the city of San Diego had an estimated population of 1.25 million. The entirety of San Diego County had an estimated population of 2.9 million. In comparison, the population of Tijuana in 2005 was estimated to be 1.47 million. San Diego’s land area is 372 square miles while Tijuana’s land area is 246 square miles San Diego’s population density is 3,360 people/square mile while Tijuana’s population density is 5,975 people/square mile, nearly twice as dense as San Diego. One could argue that Tijuana is really the core city, and San Diego its most populous suburb. Or at the very least, it would have co-center status, the way that the San Francisco Bay Area is centered around both San Francisco and San Jose—while San Jose is the larger city, San Francisco has the cultural cachet.

The megalopolis that exists now on the West Coast has been called Bajalta California, which includes L.A. San Diego, Tijuana, and Mexicali. This is, however, an urban studies term. The more colloquial term is probably just Southern California, or alternately, SoCal (which I think is most popular among my generation), or, as the local news networks put it, the Southland (although I think this is generally restricted to the Los Angeles-Orange County-Riverside consolidated metropolitan area and typically does not include San Diego or Imperial Counties)

This conurbation could actually be defined by the convergence of now obsolete routes, namely US-101, US-99, and US-80. All these routes have been decommissioned (While US-101 still exists north of L.A., it used to go all the way to the border.) US-101 and US-99 meet in downtown L.A. US-101 and US-80 meet in downtown San Diego. US-99 and US-80 meet in El Centro, which is just north of Mexicali.

Having grown up in L.A., you tend to get the myopia and narcissism characteristic of anyone from a major metropolitan area. New Yorkers are notorious for this kind of provincialism. In any case, for the longest time I’ve thought of San Diego as the southernmost suburb of L.A., and Las Vegas as the northeasternmost suburb of L.A. My conception of Southern California has been thus: San Diego to the south, Ventura and Santa Barbara to the west, Palmdale/Lancaster to the north, Las Vegas to the northeast, San Bernardino and Riverside to the east. In contrast to other metropolitan areas, where the downtown areas are incredibly dense and then the density tapers off quickly as you reach the periphery, something which I noticed of New York and Chicago, Southern California is almost of constant uniform density from core to periphery. Except for Camp Pendleton, you can drive from San Ysidro at the Mexican border all the way to Santa Clarita to the northwest or Palmdale/Lancaster to the north without once leaving the city. To the northeast, you only really enter the desert once you leave Barstow. To the east, you have to go as far as Palm Springs. To the west, it’s not until US-101 bends from east-west to north-south.

L.A. is often wrongly impugned as the origin of sprawl, but interestingly some observers actually consider it the most densely populated metropolitan region in the U.S. The population density of the urban core of the Southland is about 7,000 people per square mile as of 2000 (still more than twice as dense as the fourth largest city in the country, which is Houston, a far better example of sprawl gone wild), but there are neighborhoods where the density is as high as 36,000 people per square mile (in particular, Westlake, the next district west from Downtown.) This is half as dense as Manhattan (which has 67,000 people per square mile)

But it’s mostly the impression I get when I fly into LAX. I recall flying into O’Hare or JFK, where all you see is farmland, and then all of the sudden, the huge dense urban district pops into view. (The view of NYC from the sky still amazes me. It’s just miles and miles of huge buildings.) When you fly into L.A. from the east, the urban area starts when you’re still at least 30 minutes out, and this doesn’t even take into account delays and circling around. The urban carpet just goes on and on and on. Most cities, you can see the borders from the air, where suburbs give way to farmland, but L.A. spreads from horizon to horizon.

There is also the putative megalopolis called SanSan that basically includes all the urban areas of California, from San Diego to San Francisco. It’s hard to make the argument that there is a continuous urban chain from S.D. to S.F., particularly if you follow the I-5 corridor. But the (former) US-99 corridor is actually growing quite rapidly. You could make a case for a continuous chain of cities from L.A. to S.F. via Santa Clarita at the I-5/US-6 (now California 14) split, north through Palmdale/Lancaster all the way to Mojave, then east to Bakersfield, north on US-99 (now California 99) to Fresno, the largest city in the country not served by an interstate highway, through Stockton and Sacramento, and finally west to the Bay Area. While I wouldn’t say the urban presence is continuous, I can see how it might eventually become so after a few years. The US-99 corridor is growing fast.

You finally leave civilization entirely just north of Sacramento on the I-5, and there’s a huge gap between Sacramento and Portland, as well as between Portland and Seattle. It’ll take decades or so before those gaps ever fill in, but it might be quicker than I think.