I-5 Widening Project at Manchester Avenue

The Project

The I-5 Widening Project at Manchester Avenue is a part of the larger I-5 North Coast Corridor Project. This 27-mile project will add highway lanes and operational improvements to provide mobility choices for motorists on Interstate 5 (I-5) in the northern San Diego region. The project extends along I-5 from La Jolla Village Drive in San Diego to Vandegrift Boulevard in Oceanside. The corridor is critical both for commuters and goods movement.

  • Two Express Lanes in each direction will be added from La Jolla Village Drive to Vandegrift Boulevard. The Express Lanes will be free for carpools, vanpools and buses, and available to single-occupant vehicles for a fee.
  • Operational improvements, such as auxiliary lanes and local freeway interchange modifications, will be added incrementally in key locations to improve traffic flow.
  • Environmental enhancements will preserve, protect, and restore hundreds of acres of critical coastal habitat and improve 27 miles of bike lanes and pedestrian paths along the coast and throughout local lagoon areas.


The Need

The I-5 North Coast Corridor experiences recurrent traffic congestion during weekday rush hours and also is heavily traveled on weekends. I-5 is the lifeline connecting San Diego to Los Angeles County, Orange County, and Baja California.

  • Average daily traffic on I-5 is more than 200,000 vehicles and is projected to increase to more than 300,000 vehicles by 2030. More than 10,000 daily truck trips are made on I-5.
  • I-5 is important for commuter, commercial, and recreational travel. Without capacity improvements, the increases in traffic in the corridor will result in congestion throughout the day.
  • The arterial roadways parallel to I-5 are segmented and do not provide a continuous north-south alternative route to the freeway. No new parallel arterial roadways are planned. The COASTER commuter rail service is being expanded. However, I-5 will continue to carry the burden of trips in the corridor.


Project Costs

The total costs for additional highway lanes is estimated at $3.1 billion (2011 dollars). Of this amount, $483 million will be used to construct the extension of the existing carpool lanes from Manchester Avenue to State Route 78 (SR 78), replace the San Elijo Bridge, and construct sound walls.


Project Status

The final environmental document was certified in early 2013. The Coastal Commission voted unanimously in August 2014 to approve the North Coast Corridor Program’s Public Works Plan/Transportation and Resource Enhancement Program. The document provides the blueprint for the NCC Program, a balanced, 40-year transportation plan which includes highway, rail, environment, and coastal access improvement projects. In conjunction with the NCC Program, five incremental operational improvement projects have been developed to provide immediate congestion relief:

  • A northbound auxiliary lane from Del Mar Heights Road to Via de la Valle was completed in late 2004.
  • The extension of the existing northbound HOV lanes from Via de la Valle to Manchester Avenue and the interchange improvement at Lomas Santa Fe Drive were completed in February 2009.
  • The extension of the I-805 HOV/Carroll Canyon Road was completed in early 2014
  • The widening and replacement of the I-5/Genesee Avenue interchange began construction in early 2015.
  • The extension of the existing HOV lanes from Manchester Avenue to SR 78, including the replacement of San Elijo Bridge, began construction in 2016.

Funding Status

A total of $560.6 million has been secured from a combination of federal, local, and state funds. The money consists of $35.1 million in federal funds, $52.5 million in state appropriations, and $473 million in funding from the regional TransNet half-cent sales tax for transportation improvements. The project has been identified as a high priority by SANDAG and is part of the TransNet Early Action Program.