Tag Archives: Bundy-Centinela

Sepulveda/LAX Transit Part 4: Arrested Arterials, Arrested Development

Los Angeles has a great arterial grid. Almost.

As Jarrett Walker says, grids are great for transit, because they let you efficiently serve a large geographic area with high-frequency service, while avoiding the problems of branching. In that post, Walker calls Los Angeles and Vancouver “two of the most perfect transit cities I’ve ever seen, in their underlying geography.”

Well, almost.

Aside from the obvious topographical barriers like the Santa Monica Mountains, there’s a weakness in LA’s arterial grid: on the Westside, practically nothing west of La Cienega is worthy of being called a north-south arterial. East-west movement is another story, an embarrassment of riches: Pico, Olympic, Santa Monica, Wilshire, and Venice. There’s not one north-south arterial that’s as good as any of those east-west boulevards. This is part of why the 405 is so horrendous and traffic on the Westside in general, the largest bugaboo of Westside NIMBYs, is terrible. Most importantly, it has significant implications for what high quality north-south transit on the Westside will look like.

Let’s take a closer look. The map below shows how many lanes each Westside arterial has in each direction. It also shows peak-hour only lanes (created by parking restrictions) with dashed lines. I realize many readers may not be particularly worried about auto capacity, but the number of traffic lanes is a reasonable proxy for both the technical and political challenges to creating a dedicated right-of-way (ROW) for transit.


How Did We Get Here? Or, A Boulevard for Our Kingdom

It wasn’t supposed to be this way.

Believe it or not, parts of the Westside were undeveloped as recently as the end of World War 2. Older urban nodes, like Palms, Santa Monica, Westwood, Venice, and Beverly Hills, were scattered among farmers’ fields and country clubs. After the war, with construction of the 405 and UCLA, the areas in between these nodes rapidly developed as single-family neighborhoods. Partly due to preexisting development, and partly due to poor planning foresight, adequate ROWs for north-south arterials were not reserved. (Note that this mistake is rarely repeated nowadays; suburban sprawl is planned with ridiculously wide ROWs saved for arterial roads.)

Despite having been developed with single-family residences (SFRs), at that time much of the Westside was zoned for multiple-family development. As discussed previously, by the 1950s, low-rise apartments known as dingbats were popping up in the more established neighborhoods, such as Palms, and in the area near UCLA.

By the early 1960s, high-rise residential towers were sprouting up along Wilshire Blvd, as detailed in the city’s 1963 Westwood Economic Study. By the city’s generous standard of high-rise (4+ stories), there were 19 buildings in this class completed or under construction. The study noted that “rents in the newer high-density apartments [were] considerably higher”. The average monthly rental for a one-bedroom in a high-rise in 1963 was $2,370/month; compare this to one-bedroom dingbat apartments in Oakland, renting for $820/month at the same time, or in Palms, renting for $610-$820/month in 1970. (All values 2014 dollars.)

However, the study went on to note that there was no reason to worry about these expensive rentals, because “increasing demand for apartments on the part of the lower-middle and low income groups. . . can be satisfied in part by the older portions of the existing housing supply, and in part through new smaller apartment structures which could be built at lower cost. Such structures are being built in quantity throughout the city and metropolitan area. . .” Yep, you know who that is.

The rapid changes on the Westside came with growing pains. For example, the Palms-Mar Vista-Del Rey Socioeconomic Study (1970) found that population increased from 19,399 in 1940 to 78,134 by 1956, after which time further growth required replacement of SFRs, some scarcely more than a decade old, with multi-family developments. In 1950, Palms-Mar Vista had 2,361 apartments and 11,859 SFRs; by 1970, 15,883 apartments and 13,100 SFRs, with the number of SFRs having peaked in 1960 and by then declining as they were replaced by apartments.

Probably the biggest change, though, was Century City bursting onto the scene in 1963, rising from a former Fox studio backlot. Along with continued growth at UCLA, Westwood, and Santa Monica, the Westside was becoming one of the most important business districts in Los Angeles. The Westside’s boom strained the area’s underpowered road and transit network, resulting in worsening traffic congestion. In particular, Century City is poorly located and laid out with respect to north-south traffic movement. (Perhaps its developers quite logically expected redevelopment of adjacent golf courses, allowing Avenue of the Stars to be extended north and south.)

The city did not sit idle in the face of this congestion. While the need for rapid transit along the Wilshire Corridor was already well-recognized by the early 1970s, the plans drawn up for north-south movement reflected that auto-centric era. City traffic engineers proposed widening many north-south roadways, including every one shown on the map above between La Cienega and Lincoln (except Sepulveda, which presumably was already an arterial). These plans were backed by City Councilman Louis Nowell, a notoriously pro-growth politician who, in addition to greater urban density, also supported questionable amenities like the Laurel Canyon and Beverly Hills Freeways, and oil drilling in Pacific Palisades.

Westside SFR owners, having bought into the suburban dream only to find themselves in the midst of a booming metropolis, understandably did not share Nowell’s vision. By November 1972, the LA Times reported that opponents of density and street widening, dubbed “environmentalists”, had succeeded in getting the city to cancel plans for Castle Heights-Beverwil and Motor in the West LA plan area. The West LA plan was approved in December 1973. Further west, the Times reported that by early 1974, Mar Vista residents were protesting street widening in their neighborhood. By December 1974, city planners had relented, only proposing to widen Bundy-Inglewood and Barrington-McLaughlin-Slauson. Unsatisfied, voters elected a slate of “environmentalist” candidates to the city council, which proceeded to eliminate all north-south improvements save Centinela in early 1975.

Nowell complained bitterly, arguing that the West LA Plan would “[turn] this city back into a bike and horse economy, like some cruddy little town” and predicting that the Palms-Mar Vista-Del Rey Plan would turn LA into a “cow town because you can’t get around”. The city traffic engineer warned that “if people think traffic in the area is bad now, they ain’t seen nothing yet”. City Councilor Marvin Braude, one of the “environmentalist” councilors, argued that they had shifted the planning process on the Westside “to such things as car pools and rapid transit”, a claim that the last 40 years of history has proven dubious under the most generous definition of the word. Other opponents of development posited more metaphysical arguments, such as “suppose they widened the streets and no cars came”.

Ultimately, widening was restricted to Robertson, Overland, and Bundy-Centinela, though vestiges of the planned wider roads can still be found from Beverwil to Barrington. This requires the city to try to coerce Century City traffic into traveling over a mile east or west before heading south to access the 10.

Opponents of development also secured significant downzonings with the West LA Plan and Palms-Mar Vista-Del Rey Plan. The latter plan, calling for preservation of SFRs, restricted zoning for apartments to areas where they were already being developed, primarily the area of Palms east of Overland with a few tendrils extending to the west. This was expected to reduce the population at build-out from 168,000 to 130,000. (Unfortunately, the articles don’t say how many units this represented; obviously, regional prices and rents will have an impact on household size, and consequently on population.)

The West LA Plan likewise downzoned areas that had been zoned for multi-family development, and expected to reduce population at build-out from 135,000 to 106,000. Around the same time, the permissible density of Century City was reduced, including a reduction in commercial space as well as slashing the number of residential units allowed from 8,000 to 4,000. The density allowed on Wilshire Blvd was also reduced.

By 1975, a new plan was in place for the Westside, one that envisioned a future of lower density and less traffic, but would only deliver on one of those promises.

Fast Forward to Today

There would be further challenges to urban density in the intervening years. For example, the Braude and Zev Yaroslavsky-backed Prop U (1986), reduced allowable FAR in most of the city’s commercial zones from 3 to 1.5. While Prop U targeted commercial development, C1 & C2 zones allow R3 & R4 uses by default, so Prop U effectively reduces residential development opportunity as well.

Century City commuters stubbornly refused to use Overland and Robertson, leading to further resident outcry over “cut through” traffic. But despite the promises of shifting planning away from the automobile, rapid transit and pedestrian/bicycle plans have also been stymied since that time. Plans for a subway on Wilshire were delayed for years by Henry Waxman’s 1985 ban on federal funds for subway construction on the Westside, and Zev Yaroslavsky’s 1998 ballot measure that precluded use of Measure A and Measure C funds for such purposes. The Expo Line will open soon, but only after overcoming several lawsuits from Cheviot Hills and Rancho Park residents. Westside streets remain auto-oriented, with some lacking sidewalks, and bike lanes being opposed by resident groups like the Westwood South of Santa Monica Homeowners’ Association.

Where Do We Go From Here? Or, Our Kingdom for a Boulevard

It should be clear that, in the modern framework of thinking about cities, there are no clean heroes or villains in this story. On one side, you had support for greater urban density, to be enabled by widening streets all over the place and hacking the Laurel Canyon, Beverly Hills, and Slauson Freeways into existence. On the other side, you had strong “environmentalist” support for eternal SFR neighborhoods without any meaningful support for rapid transit, resulting in innumerable hours of traffic misery for people forced to commute on the 10 and the 405.

For our purpose here – north-south transit on the Westside – we need to understand this history, and how it affects the transit options that are available. Congestion and the uneven street grid make it difficult to lay out effective, efficient transit lines on surface routes, but the low density neighborhoods call the practicality of fully grade-separated transit into question. From a transit perspective, the two biggest gaps in the arterial network are probably the lack of a direct north-south connection from Century City to points south, and the incomplete Barrington-McLaughlin-Slauson arterial. The former makes it difficult to plan any north-south transit service to Century City, including connection to the Expo Line, the only high-quality rapid transit service in the near term. The latter would allow for a nice surface BRT route from the Slauson Corridor to West LA along roads with no ramps to the 10 or the 405, avoiding the congestion caused by such facilities.

This post is not to say that all these street widening projects should be resurrected. US cities seem to be unusually adept at destroying themselves that way, though other cities since the time of Haussmann have shown you can have wide boulevards that are an urban amenity, and arterials that will hopefully have high-quality transit someday, like La Cienega, came into existence that way. The takeaway here is that the north-south roads, as they exist today, are the reality we have to work with, and they are going to make it difficult to get exclusive or semi-exclusive ROW. It’d be convenient if we had an Olympic Blvd, but we don’t. More on the potential north-south transit services next time.

For opponents of development on the Westside, the question is more philosophical, and I’d put it like this: you’ve been tilting at the windmills of traffic and density for 50 years now. But no neighborhood is an island. Century City can’t be unbuilt. UCLA and LAX aren’t going anywhere. Santa Monica, Venice, and Playa Vista are some of the hottest commercial markets in the region. People living in the Valley and South Bay are always going to have reasons to travel to the Westside; service industry workers are always going to need a place to live and a way to get to work. How much longer are you going to keep fighting a battle that can’t be won the way you’re fighting it?


Westwood Economic Study, City of Los Angeles (1963)

The Low-Rise Speculative Apartment, Wallace Francis Smith (1964)

Palms-Mar Vista-Del Rey Socioeconomic Study, City of Los Angeles (1970)

“Palms-Mar Vista Preliminary Plan Calls for Apartment Zone Rollback”, LA Times (January 23, 1972)

“West LA Plan Proposals Face Bitter Opposition”, LA Times (June 29, 1972)

“Resident, Developers Angered by Proposed Plans for Century City”, LA Times (August 13, 1972)

“Planners Will Tackle WLA Traffic Problems”, LA Times (November 12, 1972)

“Traffic Fears Delay WLA Plan’s Approval”, LA Times (November 19, 1972)

“West LA Plan Foretells Severe Traffic Congestion”, LA Times (March 11, 1973)

“West LA Plan Approved Over Protests Noise Was Ignored”, LA Times (November 15, 1973)

“West LA Plan OKd, Called Move Away From Autos”, LA Times (December 20, 1973)

“Mar Vista Resident Group Hits City Plan”, LA Times (February 24, 1974)

“Palms-Mar Vista Plan Approved”, LA Times (December 26, 1974)

“Environmentalists ‘Sweep’, Community Plan Wins Approval”, LA Times (April 24, 1975)

Sepulveda Pass and LAX Transit

Since both of these topics have been in the news a lot lately, it’s about time for a look at north-south transit on the Westside.

Sepulveda Pass in Context

Before we start laying out transit lines, we need to understand the urban context of the area in question. This is especially important for rail transit and other high capital cost projects, because bad decisions will haunt us for a really long time. So…

First, in terms of network design, Sepulveda Pass is a world-class bottleneck, right up there with San Francisco Bay and the Hudson & East Rivers. Your reaction to that, might be, “well, duh”, but we need to realize the implications for network design. Jarrett Walker goes into more detail in Chapter 4 of Human Transit but the chief points here are that (a) more deviation from straight routes is acceptable at bottlenecks and (b) bottlenecks are natural locations for transfers between parallel transit lines.

Second, in terms of engineering and cost, Sepulveda Pass is a very challenging and expensive area. We’re looking at a 7-mile tunnel from Westwood to Sherman Oaks, hundreds of feet deep in the middle. Vertical access between the tunnel ends is difficult at best for ventilation, and impossible for a station or emergency exit. This suggests that within the current planning time frame, we’re only going to get one shot at transit through Sepulveda Pass, so we’d better do it right and get a ton of capacity out of it. In 106 years, New York has managed to build only seven crossings of the Hudson, to connect all of Manhattan, the Bronx, Brooklyn, & Queens with all of New Jersey.

Therefore, any tunnel through Sepulveda Pass should serve multiple transit lines on both sides, and provide as much capacity as possible. The stations at each end will be natural transfer points between the lines. It doesn’t make sense to go to the expense of building a tunnel that long if all it’s going to serve in the Valley is one LRT line on Van Nuys. The tunnel should serve at least two lines on both sides, and probably more. We don’t have to actually build all of the lines right away; the important thing is that the piece from Westwood to Sherman Oaks is built properly at the outset. This is probably a great location for one of Alon Levy’s large diameter TBM tunnels, with four tracks running from Westwood to Sherman Oaks, since there won’t be any stops in between.

This also means that the tunnel should serve rail traffic exclusively and have no auto lanes. In addition to having a lower capacity, auto lanes have much heavier requirements for ventilation. There’s also the question of what facilities auto lanes would connect to at each end, since it’s not like there’s a ton of spare capacity kicking around on the 405, the 10, and the 101. (Note: you could argue for a bus tunnel, using dual-mode buses, with exclusive lanes on arterials for the rest of the lines. I’m not going to get into a bus vs. rail analysis here, since the quality of the ROW is more important than the technology.)

Transit Lines Through Sepulveda

Now that we’ve established what the facility through Sepulveda Pass should look like, we can lay out some transit lines to go through it. In my mind, the logical candidates for north-south transit in the Valley are Reseda, Sepulveda (Valley section), Van Nuys, and maybe Balboa. (Anything east of Van Nuys, at least IMHO, is a future north-south line to connect to La Cienega.) There’s also the potential for east-west lines on Venutra, west to Warner Center and east to Burbank. On the Westside, the north-south candidates are Lincoln, Bundy/Centinela, Sawtelle, Sepulveda (Westside section), Westwood/Overland, and maybe, as a stretch, Avenue of the Stars/Jefferson.

Personally, I’d leave Ventura alone as a separate east-west project. Sawtelle is too close to Sepulveda (Westside), so it doesn’t make the cut. The appeal of the Avenue of the Stars/Jefferson route is that it would serve Century City directly from the Valley, but the resulting line has such poor overall geometry that it wouldn’t be very useful for anyone not going to Century City, so I think it’s out as well.

The other intriguing option, which has been suggested by Henry Fung elsewhere, is having the Westside Subway Extension turn north in Westwood and go to the Valley. Assuming the other lines would be LRT, extending the Purple Line would create some technical challenges (including differing vehicle width). I’ll leave that for a future post focusing on that alternative. This option would take care of Century City.

Here’s a rough plot of these options with reasonable stop spacing:


Don’t worry too much about the stop spacing for now; we’ll take a closer look at that in future posts. Remember, the important thing at the outset is to serve the right area and choose logical overall route alignments. You also might guess from this graphic that I’ve got some changes in mind for Metrolink in the Valley. Yet another topic for yet another future post.

In terms of sequencing, the consensus is that Van Nuys is the top priority in the Valley. On the Westside, Sepulveda (Westside) and Westwood/Overland are only ½ to ¾ of a mile apart, so whichever of the two is built first, the other should be built last. I’d do Sepulveda (Westside) first, if only because it’s more centrally located and spreads the wealth. It’d be useful to some future users of the Bundy/Centinela and Westwood/Overland lines, whereas those two lines wouldn’t help each other’s riders much. The argument for Westwood/Overland first is that it’s closer to Palms and Culver City, which are denser than Mar Vista, and it’s a good enough argument that you could probably talk me into it.

I’d sequence the lines as follows:

  • Van Nuys and Sepulveda (Westside)
  • Reseda and Lincoln
  • Sepulveda (Valley) and Bundy/Centinela
  • Balboa and Westwood/Overland (no Westwood/Overland if Purple Line is extended)

The benefits start immediately with the first line completed, and are amplified as additional lines are finished. To the south, future phases could extend the lines out Florence, Manchester, Century, Hawthorne, Sepulveda/PCH… more than enough possibilities to leave for a future post.

LAX Transit

Note that all these lines naturally converge near Sepulveda & Century, right at LAX’s front door, and would serve far more people than any LAX rail transit proposal on the board now. So in addition to serving LAX, basically at the future Terminal 0, this project would directly serve a couple million other people who might or might not be going to LAX. In other words, this plan would follow one of Jarrett Walker’s main principles: be on the way!

You might have noticed in the first graphic that I didn’t show any connection from the new lines to the Green Line & Crenshaw Line. Clearly, you’d want to provide that link somehow.

Here’s one option for an initial build with two lines. In this scenario, the Crenshaw Line would take over the Green Line’s route south of Aviation/Imperial, and the Green Line would be extended a mile west to meet up with the new Reseda-Lincoln Line. This gives the combined Reseda-Lincoln-Green Line and the Van Nuys-Sepulveda (Westside) Line front door access to LAX, with decent geometry and without making any through passengers go out of their way.


I’ve violated my own rules on stop spacing in El Segundo, going to half a mile to provide a Green Line stop at Maple and a Sepulveda Line stop at Mariposa. With this level of transit service, easy access to LAX, the 105, and the 405, there’s no reason El Segundo’s business district couldn’t become LA’s third downtown.

Here’s an option for full build with four lines.


In this case, I’ve routed Balboa and Bundy/Centinela together, and the line could be extended out Florence towards South LA, HP, Bell, Cudahy, Bell Gardens, and Downey – all dense cities that should get good transit use. I’ve also shown the Purple Line being extended to the Valley and up Sepulveda.

Again, don’t worry too much about the specific stations and routings – we’ll go into more detail on each option in the future.

To Bore or Not to Bore

The decision to tunnel is one of the biggest ones that must be made. Tunneling results in faster speeds and more reliable operations, but the higher cost can push project completion further into the future. Obviously, we’re tunneling through Sepulveda Pass, but on either side, it would be possible to do full tunnels, surface running with selected grade separations (like Expo Line and Crenshaw Line), or full surface running.

Any surface running segments are dependent on the ROW of the arterial roads. Contrary to popular conceptions of LA, the north-south arterials on the Westside are somewhat underpowered. Lincoln and Sepulveda (Westside) are two lanes each way with a center turn lane. Bundy/Centinela and Westwood/Overland are cobbled together, with pieces where the second travel lane is only provided during peak periods by sacrificing on-street parking (always a sign of desperation).

The situation is much the same on Reseda and Balboa, which have the same basic configuration as Sepulveda (Westside), but with more generous proportions. On Balboa, there are three lanes each way with no parking. Sepulveda (Valley) and Van Nuys are wider, at least three lanes each way with a center turn lane plus parking. In many places they’re even wider (presumably where there used to be transit ROW in the middle).

I was going to go into detail and compare grade separation options for each branch, but that would make this post much too long. Now that we’ve got the basic framework set up, we can come back and give each branch the attention it deserves in future posts.