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The Los Angeles County Metropolitan Transportation Authority (Metro), the California Department of Transportation (Caltrans) and contractor Kiewit Infrastructure West (Kiewit) have completed the I-405 Sepulveda Pass Improvements Project.

With the opening of the 10 miles of new northbound high-occupancy vehicle (HOV) lanes between the I-10 and US 101, the project added much needed capacity to the nation’s busiest freeway and closed the last remaining gap in the entire I-405 carpool lane network. The project seeks to:

  • Decrease commuter time
  • Reduce air pollution
  • Promote ridesharing

Besides removing and replacing three major bridges—Sunset Bridge, Skirball Bridge and Mulholland Bridge—the project team widened 13 bridges over City of Los Angeles streets. The project also reconstructed 17 ramps from the westbound I-10 connector to the northbound I-405 to the southbound off-ramp to Valley Vista Bl. In addition, workers constructed approximately 18 miles of retaining walls and sound walls.

Below are a few other improvements the project team added to the crucial I-405 freeway.

Wilshire Segment

Nowhere was improvement seen more than at the Wilshire Bl/I-405 interchange. Before the project, drivers merging on and off the I-405 were overwhelmed with drivers traveling east and west on a heavily congested Wilshire Bl. This created a potential safety hazard for commuters and caused many hours of delay each year.

To eliminate these congestion and safety issues, all eight ramps connecting the I-405 freeway with Wilshire Bl were rebuilt to separate traffic, eliminating cross-traffic patterns and allowing for safer and smoother transitions. Increased car capacity on the eight ramps also means less traffic backup along Wilshire Bl. In addition, the reconstructed Wilshire Bl ramps meet the latest seismic standard.

Southbound motorists traveling the I-405 benefit from the restriping of the freeway under the I-10. Instead of three lanes, motorists can now drive on four lanes.

Sunset Segment

Besides upgrading Sunset Bridge to modern seismic standards, the reconstructed Sunset Bridge added a new lane in each direction, allowing three westbound lanes, three eastbound lanes and two lanes devoted to eastbound Sunset Bl on-ramp traffic to northbound I-405.

The reconfiguring of the Moraga Dr ramps allowed for double left-turn lanes onto the northbound Moraga Dr on-ramp from northbound Sepulveda Bl.

When the project shifted Sepulveda Bl east to allow for the new northbound lane, approximately two dozen utilities were moved, allowing workers to upgrade the utilities to modern standards. Near Sunset Bridge, Sepulveda Bl was rebuilt (not just repaved) to a depth of approximately two feet, increasing the busy road’s longevity.

Mulholland Segment

All of the reconstructed bridges meet the latest seismic requirements. Mulholland Bridge was also widened to allow for wider sidewalks along the signature bridge and a widened center median.

Mulholland Bridge contains multiple utilities, and these were upgraded while the bridge was rebuilt. Rebuilding Mulholland Bridge was the reason for Carmegeddon I and Carmegeddon II, the complete closures of the I-405 freeway in the Sepulveda Pass.

Besides lengthening Skirball Bridge, the project team also addressed a persistent traffic problem at the Skirball Center Dr and Sepulveda Bl intersection: the southbound Skirball Center Dr on- and off-ramps were relocated approximately 2,000 feet south of their location adjoining the intersection.

Relocating the ramps reduced congestion and improved traffic flow in the street network around Skirball Center Dr, allowing better traffic signalization all the way to Sunset Bl.

The project team added:

  • Third northbound lane between the new southbound ramps and Skirball Bridge
  • Dedicated double left-turn pocket for vehicles entering the southbound I-405 freeway from southbound Sepulveda Bl
  • Dedicated right-turn pocket for traffic entering the southbound I-405 freeway from northbound Sepulveda Bl
  • Northbound bike lane on Sepulveda Bl between the new ramps and the Skirball Bridge
  • Wider shoulders on southbound Sepulveda Bl

Project Overview

The I-405 Sepulveda Pass Improvements Project will add a 10-mile HOV lane and improve supporting infrastructure such as ramps, bridges and sound walls on the San Diego Fwy. (I-405), while widening lanes from the Santa Monica Fwy. (I-10) to the Ventura Fwy. (US 101).

This project will reduce existing and forecasted traffic congestion on the I-405 and enhance traffic operations by adding freeway capacity in an area that experiences heavy congestion. In addition to these modifications, the project will improve both existing and future mobility and enhance safety throughout the corridor.

Project benefits include a decrease in commuter time, reduction in air pollution, and promotion of ridesharing.

The I-405 Sepulveda Pass Improvements Project will:

  • Add a 10-mile HOV lane on the northbound I-405 between the I-10 and US-101 Fwys.
  • Remove and replace the Skirball Center Dr., Sunset Bl. and Mulholland Dr. bridges
  • Realign 27 on- and off-ramps
  • Widen 13 existing underpasses and structures
  • Construct approximately 18 miles of retaining walls and sound walls

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The I-405 Sepulveda Pass Improvements Project utilizes Twitter to post closure updates every workday afternoon. For your convenience, the updates are organized by segment. You can also view these Daily Updates on our Facebook, Twitter.

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The abbreviations below help us organize the Daily Updates by segment.

All Segments

Wilshire Segment (National Bl to Waterford St)

Sunset Segment (Waterford St to Getty/Sepulveda Bl)

Mulholland Segment (Sepulveda Bl to US 101 Highway)

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