If you drive Diablo Road between Fairway Drive and Alameda Diablo, you already know the drill. A flagger waves you into a single alternating lane, you wait behind six or eight cars, and you watch a construction crew work near the creek before your turn comes to move. It has been going on for months, and if you have kids at the schools along that stretch, you have felt it hardest during drop-off and pickup.
Most residents assume this is a utility project or a road widening. It is neither. The Town of Danville is finishing a trail connection that first appeared on paper in 1989, and the reason it took this long has almost nothing to do with money and everything to do with who owned the land underneath it.
What's Actually Getting Built
The project has a formal name, the Diablo Road Multi-Use Trail, and a specific job: a paved, 8-foot-wide Class 1 path running along the south side of Diablo Road that will eventually stretch 2.1 miles between Green Valley Road and Blackhawk Road, extending access toward Mount Diablo State Park.
The piece under construction right now is smaller and more specific than that full 2.1 miles. It is a 0.9-mile segment running from Fairway Drive to roughly 400 feet west of Avenida Nueva. That segment closes the gap between two trails that already exist but don't connect to each other: the 0.5-mile Barbara Hale Trail on one side, and a 0.7-mile trail already built inside the Magee Preserve subdivision on the other. Once this middle piece is in, those two disconnected fragments become one continuous route.
Why This Half-Mile Sat Unbuilt for 36 Years
Danville's 1989 Townwide Trails Master Plan called for exactly this connection. It stayed on paper for three decades because the land it needed to cross was privately owned, hilly, and cut through by a creek. Building a trail across someone else's working ranch was never going to happen through a town budget line item alone.
The unlock came when the Magee Preserve development was approved. As a condition of building 69 homes on the 410-acre Magee Ranch, the developer had to dedicate 93 percent of that ranch to public open space and trail construction. Part of that deal split the trail work in two: the developer would build the eastern segment inside the new subdivision, on relatively flat ground, and hand the town a public easement to build the far harder western segment, the one now under construction, where the route has to cross Green Valley Creek and climb through steep terrain.
At the project's groundbreaking, Danville Mayor Renee Morgan put the timeline in plain terms: "Over 36 years ago, we were standing here, envisioning this trail." That is not a marketing line. It is the actual gap between when the town drew this connection on a map and when it started pouring concrete for it.
What's Happening on Diablo Road Right Now
The retaining wall work near Green Valley Creek that's been slowing your commute is, by the town's own description, the largest and most impactful phase of the entire project. Traffic control between Fairway Drive and Alameda Diablo is expected to continue through approximately October 15, 2026, with one of the two travel lanes closed and vehicles taking turns through the work zone in each direction. Cars entering from Calle Arroyo are being controlled as part of the same operation, which is part of why the backups can feel long even when traffic volume looks light.
Here is the rough shape of how the project has moved since it broke ground:
- Fall 2025: Crews removed old fencing and installed construction fencing, work that mostly stayed off the roadway.
- March 2026: Construction resumed after a winter pause, with tree removal work along the corridor.
- June through August 2026: The heaviest phase began, retaining wall construction alongside Green Valley Creek, with lane closures between Fairway Drive and Alameda Diablo.
- Through mid-October 2026: Daytime traffic control continues on the same stretch while wall and grading work finishes.
- November 2026: If work is still underway, expect another pause. The project pauses each winter to avoid construction during the rainy season.
- Target: December 2026: The town's western segment is scheduled to be complete.
The $5.2 million project cost is being carried mostly by Contra Costa Transportation Authority Measure J sales tax funds, $4.7 million of it, which means the traffic delays you're sitting through aren't tied to a new assessment on anyone's property tax bill. You're already funding it every time you make a taxable purchase in the county.
What Changes Once It's Actually Done
Right now, if you wanted to walk or bike from the neighborhoods near Blackhawk Road toward Mount Diablo State Park, you'd hit a gap where the trail simply stops and you're back on the shoulder of Diablo Road with cars. Once this segment is finished, that gap closes. The Barbara Hale Trail on one end and the Magee Preserve trail on the other stop being two separate, dead-ending paths and become one route that extends access toward the park.
That is a small thing to describe and a real thing to experience. It's the difference between a trail system that looks complete on a town map and one that actually lets you get from your driveway to the mountain without merging into traffic partway through.
The Timeline That Matters to You
If your commute runs through the Fairway Drive to Alameda Diablo stretch, plan around delays through at least mid-October, especially during school drop-off and pickup windows when the town has specifically flagged heavier impacts. Watch for another pause once the rainy season hits, since that has already happened once this project cycle and it's the pattern the town has committed to. And if December comes and goes and the trail work is still visible, that likely means winter weather pushed the finish date rather than anything going wrong with the project itself.
For the most current construction updates, the town's Diablo Road Trail project page and the Danville Town Talks platform post advisories before major phase changes, usually with about 72 hours' notice.
What started as a line on a 1989 map, stalled by a creek and a private ranch nobody could touch, is now a construction zone you drive through most weekdays. That is a strange kind of progress to sit in traffic for, but it is progress all the same.
Whether you're mapping your bike route around the construction schedule or thinking ahead to what trail access near Diablo Road might mean for a future home search in this part of town, that kind of block-by-block context is what AJ Cohen Homes tracks every day. Let's Connect.
