I-15/SR 78 Managed Lanes Direct Connectors

SANDAG Caltrans SR 78 Corridor Improvements

The I-15/SR 78 Managed Lanes Direct Connectors project is a collaborative effort between Caltrans, SANDAG, and the City of San Marcos to build new direct connector ramps between the existing I-15 Express Lanes and three miles of newly proposed managed express lanes on SR 78.

Residential and economic growth along the east/west SR 78 corridor in the cities of Escondido and San Marcos has strained connections to and from I-15, a major north-south managed express lanes system in San Diego County. This strain often results in increased traffic congestion and travel delays for residents and commuters. This improvement project will help people get to their homes, jobs, and other desired destinations more quickly by improving traffic flow on and between the two corridors, leading to a better quality of life in North San Diego County.

 
Map showing new eastbound and westbound managed lanes on SR 78 and direct connectors to existing I-15 Express Lanes showing south of the SR 78. Ramp, roadway, and undercrossing improvements run north-south over the SR 78 along Woodland Parkway and East Barham Road with sections running east-west along Rancheros Drive and East Barham Road. Also running along the east side of Woodland Parkway and East Barham Road area is a new Class II bike lane. To the northeast of the bike lane, there is a new westbound auxiliary lane between Nordahl Road and Woodland Parkway. SPRINTER light rail weaves along SR 78.

New managed express lanes on SR 78 in San Marcos will connect to the existing managed express lanes on I-15 in Escondido.

Key improvements proposed as part of the project include:

  • Building direct connectors between I-15 and SR 78
  • Extending three miles of managed express lanes in each direction on SR 78 between the I-15 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

Caltrans is the lead agency on this project under the California Environmental Quality Act (CEQA) and the National Environmental Policy Act (NEPA). This project is also a top priority among direct connector projects in the SANDAG Regional Plan. The project has an estimated cost of $490 million.

For more information, check our News page for project updates, subscribe to our email list, or contact sr78@sandag.org.

Project Timeline

The project completed its preliminary planning phase in 2017.

In October 2020, Caltrans released the Notice of Preparation (NOP) for the project. This kicked off a 30-day public scoping comment period. Early public feedback on the project helped the project team develop a comprehensive list of environmental topics to study, understand community concerns, and identify opportunities for improvement. The comment period ended on Friday, November 20, 2020.

The project team collected nearly 90 public comments which will be summarized in the project’s Draft Environmental Impact Report/Environmental Assessment (EIR/EA), expected to be released in mid-2025. Key themes 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.

This project is in the final stage of the environmental review process. We expect the draft environmental document to be completed by mid-2025. A final environmental document is anticipated to be completed in summer 2026.

The project is expected to enter the final design phase in 2026. The final design is expected to be completed by 2030.
Pending funding, we expect to begin construction on the project to begin in 2030.

Related Pages