Castaic's I-5 Widening: What Commuters Should Know | Dubner
Published by Michelle & Jon Dubner | Dubner Real Estate Group | Equity Union
Last updated: July 15, 2026
The commute question comes up in almost every conversation Jon and I have with buyers considering Castaic, California, and there is real news on that front. Metro and Caltrans are in the middle of a major widening project on I-5 between Newhall Pass and Castaic, and it is worth understanding before you decide how a Castaic commute will actually feel.
Key Takeaways
- Metro and Caltrans are widening I-5 from Newhall Pass to Castaic, adding an HOV lane each direction plus truck lanes and soundwalls.
- The project ties directly to more than 25,000 new SCV residents projected by 2035.
- Metro's current estimate is spring 2027 completion, later than an earlier 2026 estimate.
- Expect ongoing construction-related delays on this stretch of I-5 until the project wraps.
What Is the I-5 North County Enhancements Project?
Metro, in partnership with Caltrans District 7, is widening I-5 from the SR-14 interchange at Newhall Pass to just south of Parker Road in Castaic. The project adds one HOV carpool lane in each direction, along with truck lanes, auxiliary lanes, four new soundwalls, one located north of Calgrove Boulevard, intelligent transportation system upgrades, and a replacement of the Weldon Canyon Bridge.
Why Is This Project Happening?
Metro's stated purpose is addressing congestion tied to projected growth of more than 25,000 new Santa Clarita Valley residents by 2035. Castaic sits at the north end of that growth corridor, and I-5 is the primary route in and out for most commuters, so this project is directly tied to how the whole north SCV is expected to grow.
For Castaic specifically, this matters more than it might for communities closer to the center of the valley. Castaic does not have the same Metrolink access that Canyon Country or Newhall have, so I-5 capacity is not just one option among several, it is the primary commute corridor for most residents heading toward Los Angeles, Burbank, or the rest of the SCV. That is part of why a freeway project this far north carries real weight for Castaic home values and daily quality of life, not just regional traffic statistics.
When Will It Be Finished?
Construction began in fall 2021 and is currently active. Metro's own project page currently estimates completion in spring 2027. It is worth knowing that an earlier news report from November 2024 had cited a 2026 completion, so the timeline has clearly slipped. We are giving you Metro's current official estimate rather than the older one, and we will update this post if that date moves again.
What Does This Mean for Your Castaic Commute Right Now?
Active freeway construction typically means ongoing lane shifts, temporary closures, and unpredictable drive times in the corridor closest to the work zone. If you are commuting daily through this stretch of I-5, build in extra time until the project wraps. On the other side of that construction window, Castaic is set to have additional carpool capacity, new soundwalls to reduce freeway noise for nearby neighborhoods, and a safer, wider corridor supporting the growth the whole valley is expecting. For buyers weighing a Castaic commute today against what it will look like once this project is done, that is the real tradeoff to think through.
How Should This Factor Into a Castaic Home Search?
Jon and I tell buyers to separate two different questions: what the commute feels like today, during active construction, and what it will feel like once the added capacity and soundwalls are in place. If you are buying with a longer time horizon, the freeway improvements are a genuine long-term positive for Castaic, both for daily commute time and for noise reduction in neighborhoods closest to the corridor. If you need to commute through this stretch daily starting immediately, it is worth driving the actual route at your normal commute time before you make an offer, rather than relying on typical drive-time estimates that do not account for current construction conditions. Home proximity to Ridge Route Road, Hasley Canyon Road, and other local access points can meaningfully change how much of the active work zone you experience day to day, and that is exactly the kind of detail Jon and I walk through with every Castaic buyer.
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Michelle & Jon Dubner · Dubner Real Estate Group · Equity Union
Frequently Asked Questions
What is being built on I-5 near Castaic?
Metro and Caltrans District 7 are widening I-5 from the SR-14 interchange at Newhall Pass to just south of Parker Road in Castaic, adding one HOV carpool lane in each direction, truck lanes, auxiliary lanes, four soundwalls, and a replacement of the Weldon Canyon Bridge.
Why is I-5 being widened through Castaic?
Metro says the project addresses congestion tied to projected growth of more than 25,000 new Santa Clarita Valley residents by 2035. Castaic is at the north end of that growth corridor.
When will the I-5 widening project near Castaic be finished?
Construction began in fall 2021 and is ongoing. Metro's current project page estimates completion in spring 2027. An earlier 2024 estimate had cited 2026, so the timeline has slipped and this post reflects Metro's most current figure.
Will there be a carpool lane on I-5 through Castaic?
Yes, the project adds one HOV carpool lane in each direction between Newhall Pass and Castaic, along with additional truck and auxiliary lanes.
Should I expect delays commuting through Castaic right now?
Active freeway construction through this corridor typically means lane shifts and less predictable drive times. If you commute this stretch of I-5 daily, it is smart to build in extra time until the project is complete.
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Written by Michelle & Jon Dubner
20 years serving Santa Clarita and Greater LA County. Certified Listing Specialist, top 1.5% of agents nationwide. Dubner Real Estate Group, Equity Union.
