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 (HOW) 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. 

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

To receive construction alerts via text message, text BuildNCC to 313131. 


Beginning in early May, Caltrans and SANDAG Build NCC highway construction crews will shift Carpool/High Occupancy Vehicle (HOV) Lane construction operations from the Interstate 5 (I-5) median to the outside shoulders in both north and southbound directions between Birmingham Drive in Encinitas and Palomar Airport Road in Carlsbad.

Work is set to begin Tuesday, May 5, and will be performed in two phases:

• Phase 1: Birmingham Drive to Batiquitos Lagoon

• Phase 2: Batiquitos Lagoon to Palomar Airport Road

Together, both phases of the transition are anticipated to take a total of eight to 10 weeks to complete (excluding Saturday and Sunday nights, and holidays). The transition will occur during overnight shifts, between 7:30 p.m. and 5 a.m., and begins with the relocation of concrete barriers (k-rail) from the I-5 median to the outside shoulders followed by restriping of the I-5 travel lanes to shift traffic toward the median.

During this shift, nearby residents and businesses can expect noise and lights, including Occupational Safety and Health Administration (OSHA) required vehicle back-up alarms. This work must be performed at night under the protection of temporary freeway lane closures for enhanced crewmember and traveling public safety. Crews will work to minimize noise and impacts to all nearby communities.  

I-5 Carpool Lane Construction

Following the successful demolition of the original 57-year-old San Elijo Lagoon highway bridges, Caltrans and SANDAG Build NCC highway crews will now begin reconstructing the new northbound and southbound interior highway bridges above the San Elijo Lagoon. The interior bridge reconstruction process will take approximately two years to complete and begins with the formation of new bridge foundation columns.

To build these new foundations, crews will first install steel casings to help form Cast-In-Drilled-Hole (CIDH) underground concrete bridge columns. In total, 22 columns will extend 160 feet deep and 8 columns will extend 220 feet deep into the ground and will allow the bridges to support heavy loads and withstand seismic events. Build NCC crews will use a hydraulic oscillator that rotates steel casings in a circular motion back and forth into the ground rather than a standard heavy-duty pile driving operation.

Bridge column foundation work is set to begin Monday, April 6, and will take place intermittently between the hours of 7 a.m. to 5 p.m., from Mondays through Saturdays (excluding nights, Sundays, and holidays). Crews anticipate taking eight to ten weeks to complete the interior bridge column foundations.

Nearby residents and businesses can expect noise and minor vibrations during this activity, including Occupational Safety and Health Administration (OSHA) required vehicle back-up alarms. In addition to this modified construction approach, crews will work to minimize noise and all other impacts to nearby communities. 

Manchester Bridge Work Area


Caltrans and SANDAG Build NCC highway construction crews shifted northbound and southbound Interstate 5 (I-5) traffic toward the outside of the new highway bridge. The southbound side was completed during the week of February 2, and the northbound side was completed the week of February 9. The traffic shifts were completed at night to allow crews to re-stripe and re-set concrete barriers (k-rail). This shift is the first of several transitions that will be completed along the eight-mile stretch of I-5 construction over the next several months. Please note, construction schedules are subject to change.

The same number of lanes remain in each direction, however, motorists will experience a curve in both directions over the San Elijo Lagoon highway bridge. 

As always, please use caution and Drive 55 on the 5 in the Build NCC construction zone. Enhanced “Motorist Aid” can be accessed by dialing 5-1-1 anywhere in San Diego County.


In preparation to switch operations from the widened median to the outside shoulders of I-5 in early 2020, crews are removing trees and plants along the freeway in the cities of Encinitas and Carlsbad within the Caltrans Right of Way. By working together early, the Caltrans and SANDAG Build NCC project team worked to limit the project and construction footprint and minimize the number of trees and plants required to be removed. Please see the list of Frequently Asked Questions for more information.


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


Local residents, businesses, and the traveling public can expect intermittent traffic delays, noise, dust, and heavy equipment near project areas as crews work to improve transportation options along the corridor. Nearby residents and businesses will be notified in advance of construction occurring near their property or business. Crews will work to minimize noise and other impacts to nearby residents. Your patience is appreciated during construction as we bring these important transportation improvements to North San Diego County. 

While construction crews are working in the median of the highway, the outside shoulder will always remain open for motorists to pull over should they need assistance. Motorist Aid will be available during daytime and weekday hours to help stranded vehicles get back on the highway. Simply call 511 in San Diego County and say “Roadside Assistance.” 


Community members and the traveling public are reminded that they have alternative transportation choices during construction on I-5. Learn about alternate transportation solutions and assistance for employers and commuters by visiting, calling 511 and saying “iCommute”, or emailing 


Provided below are a few key facts about Build NCC and the upcoming construction on I-5. 

• The extension of the Carpool/High Occupancy Vehicle (HOV) lanes on I-5 is part of the first phase of construction on the North Coast Corridor (NCC Program).

• Work on this portion of I-5 will include 11 sound walls. 

• The planned sound walls will be built on private property and all typically require property owner participation and consensus. 

• The Carpool/HOV lane in each direction between Manchester Avenue and Palomar Airport Road, and the sound walls will be complete by late 2021. 

• The first phase of construction on the North Coast Corridor Program, also known as Build NCC, was started in 2017 and will be complete in late 2022.

• The total Build NCC cost of I-5 improvements between Solana Beach and State Route 78 (SR-78) is approximately $850 million.   

• When complete, Build NCC will include the following project components:

o 13 miles of new highway Carpool/HOV lanes

o 1.5 miles of new rail double track 

o Seven miles of new bike and pedestrian paths 

o Over 1,200 acres of restored /preserved coastal habitat 


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