I-15/SR-78 Express Lanes Direct Connectors Project

In fall 2019, Caltrans, in partnership with SANDAG and the City of San Marcos, began the environmental process to evaluate Managed Lanes Direct Connectors between I-15 and SR-78.

New direct connectors between the existing I-15 Managed Lanes and three miles of newly proposed Managed Lanes on SR-78 are intended to improve connectivity and traffic flow on and between the two corridors, improve traffic flow and travel times, increase access to homes and jobs, and improve the overall quality of life in North San Diego County. 

Continued residential and economic growth along the east-west SR-78 corridor in the cities of Escondido and San Marcos has strained its connection to and from the I-15 Express Lanes, a major north-south managed lanes system in San Diego County. This project is anticipated to ease that strain and provide more efficient travel along these corridors. 

Specifically, the project will improve connectivity by:

• Building Managed Lanes Direct Connectors between I-15 and SR-78
• Extending three miles of Managed Lanes in each direction on SR-78 between the interchange and San Marcos Boulevard
• Adding a westbound auxiliary lane between Nordahl Road and Woodland Parkway/Barham Drive
• Relocating the eastbound SR 78 on-ramp from Barham Drive
• Widening and realigning Barham Drive from La Moree Road to Woodland Parkway
• Replacing the Woodland Parkway undercrossing
• Constructing a bike facility on Barham Drive/Woodland Parkway

Public Scoping Period 

In October 2020, Caltrans released the Notice of Preparation (NOP) for the I-15/SR-78 Managed Lanes Direct Connectors Project, which kicked off a minimum 30-day public scoping comment period. Early public feedback on the project was critical to helping the project team develop a comprehensive list of environmental topics to study, ensure community concerns are addressed, and identify opportunities to improve the project. The 30-day public scoping comment period ended on Friday, November 20, 2020.

During this time, the project team collected nearly 90 public scoping comments, which Caltrans, as the lead agency under the California Environmental Quality Act (CEQA) and the National Environmental Policy Act (NEPA), took into consideration and will summarize in the project’s Draft Environmental Impact Report/Environmental Assessment (EIR/EA).  Key themes heard across the public feedback included general impacts on traffic, traffic patterns on I-15 near the Valley Parkway on- and off-ramps, Managed Lanes operations and pricing, noise, landscaping, air quality, and proposed bike and pedestrian facilities.

A Final Environmental Document is anticipated in summer 2024. Please view the anticipated project timeline and environmental process below.

Project Timeline and Estimated Costs

The I-15/SR 78 Managed Lanes Direct Connectors Project is in the final stage of the environmental review process. Development of the Draft Environmental Document for the I-15/SR-78 Managed Lanes Direct Connectors Project continues to progress and is anticipated to be completed at the end of 2025. Caltrans and SANDAG are working closely with the cities of San Marcos and Escondido to address local and regional transportation needs and align the I-15/SR-78 connector with broader transportation efforts throughout North County, such as the North County Comprehensive Multimodal Corridor Plan (CMCP).

As work on the environmental analysis continues, progress is underway to prepare for these corridor improvements. Studies to evaluate existing and future highway noise levels are ongoing, with field measurements currently taking place. Biology, historical resource, community impact, and traffic studies to understand the construction site and the environment it shares are also in progress.  

Numerous opportunities to provide comment on the project will be available.  The project has an estimated cost of $450 million and is currently anticipated for construction in 2028, pending funding.

Regional Plan

The proposed connectors are listed as a top priority among direct connector projects in the SANDAG Regional Plan - a blueprint already in effect that is enhancing the region's quality of life through equitable, sustainable, and accessible transportation. 

Learn more about the Regional Plan at www.sandag.org/regional-plan

To stay up to date with SR-78 projects, please visit sandag.org/subscribe to sign up for updates. 

For any questions or comments on projects on the SR-78 corridor, please contact the project team by emailing SR78@KeepSanDiegoMoving.com, and a team member will respond to you promptly.