Tag Archives: Santa Monica

Westside Traffic, Peak Period Edition

A commenter on this post on Westside traffic asked if peak hour data might show different patterns, so I created similar graphics for the same roadways using the same data (Caltrans publishes peak hour, peak month, and yearly average traffic).

I’ll let the graphics speak for themselves. The peak hour patterns are quite similar to the total volume patterns, including the structural changes on the 405 and Venice coinciding with completion of the freeway widening project between the 90 and the 10. It’s actually a little surprising to see so much of a change in peak hour volumes – I would have guessed that changes in total volumes would be reflected in a shorter peak, leaving the peak hour itself relatively unchanged, rather than a more uniform change. These facilities are all near capacity, so if more cars enter the systems, peak volumes can only go up so much, and the increase would be expressed as a longer peak period and greater total delay.

I’ve put the daily volumes & peak volumes side by side so you can easily compare. Note that the y-scales are necessarily quite different. As always, click to embiggen.

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Is Westside Traffic Really Getting Worse?

Recently, the LA Times has published some articles positing that as freeway traffic gets worse, people have started using smart phone apps like Waze to try to avoid it, causing worsening congestion on neighborhood streets. The problem is that you can’t trust people’s perceptions of traffic. Traffic, like behavior of teenagers, is almost always perceived to be getting worse, data be damned.

Since Caltrans publishes freeway traffic counts going back to 2002, we can take a look at the evolution of Westside freeway traffic leading up to the last economic peak, the crash, and the current period of growth. Here’s a plot of traffic on the 10 between Lincoln and Vermont, from 2002 to 2013.

How to read: traffic volume is the vertical component. Time represented on the diagonal from top left to bottom right. The location on the freeway is represented west to east on the diagonal from bottom left to top right. So, if you follow a diagonal line from bottom left to top right, you’re seeing traffic volume on the freeway build as you head towards downtown. If you follow a diagonal line from top left to bottom right, you’re seeing how traffic has changed over time at a particular point on the freeway.

For example, following the diagonal for 2013, we can see that traffic is below 250,000 vehicles per day from Overland west, and above 250,000 vehicles per day from National east (where the line leaves the green area and enters the yellow band). Following the diagonal for Vermont, we can see that traffic volumes were above 325,000 at Vermont from 2002 to 2006, then between 300,000 and 325,000 from 2007 to 2011, and then back above 325,000 from 2012 to 2013.

If these graphics don’t make sense, there are some simpler line graphs at the bottom of the post showing the same freeways for years 2002, 2007, and 2013.


What can we see? Traffic declined across the whole freeway from Santa Monica to downtown LA as a result of the recession. West of La Brea, traffic volumes have not recovered or have declined even further, though east of there, traffic has started to recover. No boom in traffic on the Westside on the 10.

Here’s the 405 between the 90 and Mulholland (Sepulveda Pass). Information is the same, but the rotation is a little different to better show different patterns. I left the interchange with the 10 off the plot because it made a large, confusing dip between Olympic and Santa Monica.


From Wilshire to Sepulveda Pass, traffic volumes on the 405 haven’t increased noticeably either. There has, however, been a large increase in traffic between the 90 and Santa Monica since 2007. This correlates to both the economic recovery and the project that widened the freeway between the 90 and the 10 (induced/latent demand is real!).

Since some Westside arterials are still Caltrans-numbered routes (Lincoln, Santa Monica, and Venice) we can also look at trends on those facilities. Here’s Lincoln from the 90 to the 10.


From the 90 to Washington, traffic volumes fell in the recession and have not yet recovered to previous peaks. The stunning thing here is the drop of 10,000+ vehicles per day between Venice and the 10 freeway. It seems possible that the completion of the widening project on the 405 shifted some traffic from Lincoln to the freeway.

Further evidence for that conjecture comes from Venice between Lincoln and La Cienega.


Roughly coinciding with completion of the freeway project, Venice saw a considerable increase in traffic in the vicinity of the freeway and points east.

Lastly, here’s Santa Monica.


Nothing really jumps out here. Traffic declined during the recession, and consistent with national experience, has not recovered to previous peaks.

There’s no clear pattern of increasing traffic on these roads, but that doesn’t necessarily mean the story about worsening traffic on side streets is wrong. Technology like Google Maps and Waze makes information about the road network more accessible, and it’s certainly possible freeway and arterial traffic growth has been muted by people using the side streets. The city’s traffic data is also available through the Navigate LA website; maybe some enterprising person with programming skills can figure out a way to pull it out! Either way, it’s apparent there have been some shifts in traffic patterns, which we’d expect to make congestion worse in some places.

Note: 2009 data was missing, so I made it the average of 2008 and 2010.

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Los Angeles: Density Done Well

Wait, what’s this, an actual post on LA? ‘Bout time. I’ve been trying to cover the philosophical stuff up front to give context of where I’m coming from. I’ve still got a lot of ground to cover there, but this post provided a good opportunity to use real LA examples to back up the theory side of things.

I recently had an interesting exchange with Neal Lamontagne on Twitter, about density in Santa Monica and mid-rise versus high-rise development.


I guess that still sounds like tastes to me. Some people prefer towers – call it Vancouverism – and some people prefer sprawling low-rise and mid-rise density – call it the LA pattern, since LA invented it, perfected it, and turned itself into the densest US metro using it. Given that I’m an unabashed LA cheerleader, you can guess which way my tastes run. The LA pattern: tastes great, less filling. You can get a ton of density that doesn’t feel dense, which is perhaps LA’s most underrated achievement. It’s one of the main points of my project here.

Now, another premise of this blog is that personal tastes shouldn’t get force of law through zoning and permitting. So if I’m gonna come at you with the LA pattern, I’m gonna come correct, and give you some solid theoretical reasons you should learn to love it.

Note: Neal also raises an interesting point about the street-level impact of developments that take up an entire block. This is worthy of discussion in a separate post. For now, I’m going to focus on low-rise and mid-rise development in comparison with high-rise development.

For one, low-rise and mid-rise density offers more development model options, which leads to more diversity of use – something both Neal and I highlighted as being important. Why does low-rise and mid-rise offer more possibilities? Well, for the reason that Neal notes: it’s cheap. Lower construction costs mean lower rents, which makes it possible for a greater variety of land uses to make a go of it. There’s a good reason why skyscrapers are overwhelmingly built by the FIRE industry, luxury residential developers, and the government. It’s something Joe Satran touched on recently in the context of restaurants, too. LA has space for everybody to try their idea, and that’s an asset we ought to strengthen and reinforce when we have opportunities like Recode LA.

Lower construction costs also open the door for a wider variety of players to try their hands at land development. A low-rise or mid-rise block can be built by small-time local developers, backed by local banks, insured by regional firms. That means the development will be built and backed by people who know the city better, have a better feel for the local market, and have a bigger stake in its success. Skyscrapers require bigger developers, bigger banks, and bigger insurers, which means more generic development and less concern for the city. When I lived in Boston, a major skyscraper was derailed because Anglo-Irish Bank and CalPERS pulled funding. Not surprisingly, people in Dublin and Sacramento don’t care that much about their impact on Boston. People in LA care more about LA.

This being LA, there is one other thing we should mention: earthquakes. Contrary to what you may have heard from armchair engineers on the internet, geotechnical and structural design have made some major advances since 1906, and there is no technical reason we can’t build skyscrapers in LA, at least provided we’re not building it right on top of the damn fault. However, if you look around LA, you’ll notice that a lot of the new construction going in – say, NMS buildings in Santa Monica or the Italian series buildings downtown – tops out at, oh, I’ll guess 65’. Why? Well, get out your ASCE/SEI 7-05 and flip to Table 12.2-1…

Wait, you don’t have an ASCE/SEI 7-05?

It’s the standard design loads for buildings. Unfortunately, it’s copyrighted, so I can’t reproduce it here, but the point is this: for Seismic Design Categories E and F, the maximum height for a wood frame structure is 65’. If you’re in California, it’s almost certain you’re in E or F. If you want to go taller than 65’ you’re into special moment frames or eccentrically-braced steel frames or some other fancy structural system. This means that in LA there is a very real break point at 65’, about six or seven stories, above which there is a major non-linear jump in construction costs. Again, low-rise and mid-rise density allows for a variety of uses without breaking the bank.

None of this should be taken as being anti-skyscraper. I think skyscrapers present more significant architectural challenges than low-rise and mid-rise buildings because they present two problems that low-rise and mid-rise buildings do not: the potential for monotonous repetition of surface treatments in the middle, and the skyline view at the top. For a long time, these problems were solved by the International Style, which said that monotony and boxy tops were good things; now, they are being solved by Gehry-esque mind tricks. I’m not really a fan of either, though I do think that the early Art Deco and Neo-Gothic skyscrapers proved that these challenges can be addressed elegantly. But again, all of that is tastes. So, if a private developer thinks they build a profitable skyscraper in LA, I’m all for it!

The question we need to ask ourselves is this: what are our goals? What outcomes do we hope to achieve through things like Recode LA? Only then, goals in hand, can we proceed to determine what the best policies would be. My goals are as follows:

  • Increase housing affordability so that people spend less of their income on housing and transportation. This is usually pitched as a problem of low-income people, but it’s increasingly applicable to the middle class.
  • Make it easier and cheaper to do business, which together with the previous goal, would allow LA to resume its historic role as a place for people of all backgrounds to come and get another chance at life.
  • Make efficient use of previous capital investments in infrastructure.
  • Use the market to help reduce environmental impact.

When it comes to zoning, the best policy for achieving these goals would be allowing more low-rise and mid-rise development.

On the other hand, maybe you like the way Vancouver looks, and you want LA to be more like Vancouver. There’s nothing wrong with that, but if that is your goal, you need to understand that, and realize that other goals, like affordability and diversity of use, are going to take a back seat. But if you want to allow for density to increase quickly and cheaply, for different development models, and for greater diversity of use, you should learn to love LA!