The I-5 North Coast Corridor project will add new highway lanes and carry out improvements on a 26-mile (41.8km) section of the Interstate-5 (I-5) freeway extending from La Jolla Village Drive to Harbor Drive in Oceanside, San Diego, California, US.

Construction on the $6bn project began on 29 November 2016 and is scheduled to be completed by 2035.

Upon completion, the project is expected to provide improved, safe and efficient regional transport services.

I-5 North Coast Corridor project purpose

I-5 is an important north-south coastal corridor, which connects San Diego County and Mexico with Los Angeles Metropolitan area and the Canadian border.

Growth in population, increase in goods movement, recreational travel and tourism around the region has made the I-5 one of the busiest and most congested routes along the corridor. The same factors have also affected route operations, as well as the movement of goods, people and other services across the region.

The proposed upgrade is expected to eliminate the majority of the congestion along the segment and address the present and future projected traffic requirements along the corridor.

I-5 North Coast Corridor project details

The sponsors of the proposed project include the US Federal Highway Administration (FHWA), the California Department of Transportation (Caltrans) and the San Diego Association of Governments (SANDAG).

The I-5 NCC project includes the construction of high-occupancy vehicles (HOV) lanes in each direction, auxiliary and general-purpose lanes in each direction where needed, bridge widening, and pedestrian and bicycle lane upgrades.

The HOV lanes will be made available for carpools and vanpools, as well as single occupancy vehicles when there is enough capacity, but will not be available for buses.

Construction of the proposed project has been divided into three different phases, with phase one planned to be completed by 2020, phase two by 2030 and phase three by 2035.

Phase one of the I-5 North Coast Corridor project

Phase one of the project involves the upgrade of the I-5 segment from Manchester Avenue to SR-78. Construction of two HOV/managed lanes, replacement of the San Elijo Lagoon and Batiquitos Lagoon bridges and implementation of Manchester Avenue Direct Access Ramp (DAR) are planned in phase one.

In addition, construction of two HOV/managed lanes from La Jolla Village Drive to the I-5/I805 merge, improvement to the Voight, DAR and HOV connectors, and upgrading the Penasquitos and Soledad Creek bridges will be undertaken.

Phase one also involves community enhancements such as improvement to Voight Drive overcrossing and realignment, the addition of bike/pedestrian trail on both sides of San Elijo Lagoon and construction of a bridge connector to Manchester Avenue.

Improvements to the existing Villa Cardiff and Mackinnon Avenue bridge, and enhancements to the bike/pedestrian trail on Santa Fe Drive and Encinitas Boulevard, and North Coast (NC) Bike Trail on the San Elijo segment will also be carried out.

North Coast Corridor project phase two construction details

The second phase of the project will include the construction of two HOV/managed lanes from I-5/I-805 merge to the Palomar Airport Road, bridge improvements on the Carmel Valley Creek and San Dieguito River, and improvements to the I-5/SR-56 interchange.

Construction of bike/pedestrian trail connections at Old Valley Road, Del Mar Heights Road, Hall Property (Encinitas Community Park), Santa Fe Drive, Requeza Street, Encinitas Boulevard, Cottonwood Creek Park and Union Street will also be undertaken.

Bike/pedestrian trails near San Dieguito and Batiquitos Lagoon, Solana hills Drive trailhead, Union Street pedestrian overpass, Carmel Valley Road, Birmingham Drive and La Costa Avenue Park and rides are also planned to be constructed.

Phase two will further include enhancements to the bike/pedestrian trails at seven overcrossings and five undercrossings along the segment, and improvements to NC Bike Trail in San Diego, Solana Beach, Encinitas and Carlsbad.

Phase three of the North Coast Corridor project

The final phase of the project will involve the construction of two HOV/managed lanes from Palomar Airport Road to SR-78, and the construction of four HOV/managed lanes from SR-78 to Harbor Drive.

Construction of braided ramps from Genesee Avenue to Sorrento Valley Road, bridge enhancements at Agua Hedionda and Buena Vista Lagoons and San Luis Rey River will also be carried out.

Bike/pedestrian trail improvements at Agua Hedionda Lagoon, Bush Street and Harbor Drive/Camp Pendleton are also part of phase three.

Enhancements to the pedestrian trail and underpass at San Luis Rey River, bike/pedestrian overpass upgrade at Division Street and Mission Avenue, underpass parking/trailhead staging area improvement at SR-76 and enhancements to the NC Bike Trail at the City of Carlsbad are also to be carried out in the final phase.

Contractors involved

A joint venture of Flatrion-Skanska-Stacy and Witbeck has been contracted to provide construction services for the project.