Build NCC

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Highway, rail, environmental, and coastal access improvement projects are underway in the cities of Solana Beach, Encinitas, and Carlsbad as part of Build NCC, the first package of projects being constructed through the 40-year North Coast Corridor (NCC) Program.

Build NCC includes rail double tracking, extended Carpool/High Occupancy Vehicle (HOV) Lanes, new bike and pedestrian trails, and the restoration of the San Elijo Lagoon. These highway, rail, and lagoon improvements are being constructed simultaneously to minimize impacts to the lagoon and neighboring communities. 

Current Status:

Construction has begun on the final phase of Build NCC. This work will extend one Carpool/HOV Lane in each direction on I-5 from Palomar Airport Road in the City of Carlsbad to State Route 78 (SR 78) in the City of Oceanside creating 4 new miles of HOV lanes. This segment also includes                                                                              community enhancements like the Chestnut Avenue Intersection.                                                          Carpool/HOV construction will be complete in 2023.

Questions? Call our construction hotline at (844) NCC-0050 or email us at

To receive construction alerts via text message, text BuildNCC to (760) 454-0077. 


There is significant construction activity at the I-5/Manchester Avenue Intersection for roadway work and bike and pedestrian enhancements.  

Please note the stop sign on Manchester Avenue at the southbound I-5 on-ramp in the city of Encinitas is a temporary configuration. Once the project is complete in April 2022, a signalized intersection will stand in place of the stop sign, with 2 right-hand turn lanes to promote a smooth flow of traffic onto the on-ramp. The new signalized intersection will be coordinated with the existing signal at the NB I-5 on/off-ramp. You can view the final plans for the area here.  

Please be work zone alert and lookout for crews working in the area. Thank you for your patience throughout construction. 


Upcoming Beach Nourishment Activity at Cardiff State Beach 

Beach nourishment activity began Thursday, December 23, at Cardiff State Beach near tower 13. Starting late January, beach nourishment activity will take place Monday to Saturday 24 hours a day to ensure timely completion. The beach nourishment is anticipated to be complete in March 2022. Crews will close off the area directly surrounding the equipment with no major closures. Residents and visitors can expect to see increased vehicle traffic and construction equipment on the beachand the beach will remain open to the public. 

Sand for this nourishment project is sourced from the San Elijo Lagoon. Sand is to be dredged from the lagoon with some material hauled and piped out to Cardiff State Beach. Over 63,000 cubic yards of sand will be added to Cardiff State Beach over 4 months. The beach will remain open throughout the nourishment period. 

*Please note, construction schedules are subject to change due to inclement weather including forecasted rain, fog, or cold temperatures.  

The $870 million Build NCC project includes $195 million in funding from Senate Bill 1 (SB 1), the Road Repair and Accountability Act of 2017.  


Nearby residents and businesses can expect daytime construction noise and lights, including Occupational Safety and Health Administration (OSHA) required vehicle back-up alarms. Crews will work to minimize noise and impacts to all nearby communities. 


Please check back to receive the latest up-to-date closure notifications and detour routes. For updates by text message, text “BuildNCC” to (760) 454-0077.


Motorists traveling along the Build NCC corridor – the eight-mile stretch of Interstate 5 (I-5) between Manchester Avenue in the City of Encinitas and Palomar Airport Road in the City of Carlsbad – are advised of a speed limit reduction to 55 mph in both the north and southbound directions. The speed limit reduction took effect on March 11, 2019, and will be in place until project completion in 2022.

The speed limit reduction within the highway work zone is necessary to ensure the safety of the traveling public, and construction and public safety professionals as they work to construct the new I-5 Carpool/High Occupancy Vehicle (HOV) lanes. Construction signage will alert drivers as they enter and exit the construction zone. Electronic speed feedback signs also will be present to inform the public of their speed in relation to the reduced speed limit. Additionally, the California Highway Patrol will be actively working to ensure motorists are driving safely by enforcing the new, posted speed limit. To learn more about the reduced speed limit, click here

To view previous Construction Alerts, please visit the Build NCC Construction Notices webpage.


Project Features

Highway Improvements

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Key Documents

Factsheet Factsheet Factsheet Factsheet Pre-Construction Open House Display BoardsSanta Fe/Encinitas ImprovementsI-5/Manchester Avenue Interchange ImprovementsSegment two open house display boards