Intro — Into the Sepulveda Pass
The busiest freeway in America, about to drop through the one low gap in the mountains — eyes on the road; let this ride shotgun.
Key facts
- The I-405 (the San Diego Freeway) is one of the busiest freeways in the United States; it carries the Sepulveda Pass traffic between the San Fernando Valley and the Los Angeles Basin.
- The Sepulveda Pass is the natural low gap through the Santa Monica Mountains linking the Valley to the basin — the mountains form a barrier that regional traffic is funnelled through, primarily via this corridor.
- The pass is a low gap, summit elevation 1,130 ft (344 m) — the lowest natural crossing of the range here, not a sea-level corridor.
Narration transcript
Welcome — and before we roll, one thing about how this tour works. If you're the one driving, this is an audio tour: keep your eyes on the road and let the voice do the work. The screen is for your passenger, or for when you're parked. Nobody needs to crane their neck at a building on this trip — I'll tell you what you're passing.
Now, where you are. You're on the four-oh-five, the San Diego Freeway, heading south — and this is, by most measures, the busiest freeway in America. Ahead of you the Santa Monica Mountains wall off the whole Los Angeles Basin, and there is exactly one easy way through: the Sepulveda Pass, the low natural gap this freeway threads. Follow it and you come down into West LA and, eventually, the sea.
That's the trip: eleven miles through the pass, reading the famous buildings you can see from these lanes like a cross-section of how this side of the city chose to build. A museum on a hilltop, a canyon of condo towers, a city built on a dead movie studio's backlot. One idea, told from the lane you're stuck in.