FM 407 Widening: The Complete Guide to Southern Denton County’s Most Important Road Project

If you live anywhere along the FM 407 corridor between Argyle, Northlake, and Justin — or if you’re considering buying a home in any of these communities — this road has already shaped your daily life. It has cost you time at the wheel, patience at the light, and probably more than a few frustrated conversations about when something is finally going to get done.

Here’s the truth: something is being done. Multiple somethings, actually, happening at different levels and different timelines. And understanding the full picture — not just the headlines — matters if you’re making a real estate decision in southern Denton County or anywhere along the North Texas I-35W corridor right now.

We’re going to break all of it down. The project that’s under construction today. The broader overhaul that’s planned. The honest timeline. And what it all means for the communities we call home.

Spirit-led counsel. Straight talk. No fluff.

1.  Why FM 407 Matters

2.  What’s Happening Right Now: The Micro Breakout Project

3.  The Bigger Plan: A $235 Million, 11.5-Mile Overhaul

4.  The Honest Timeline: What’s Funded, What Isn’t

5.  The S-Curve Bypass: What Justin and Northlake Residents Need to Know

6.  I-35W Frontage Roads: The Connected Project

7.  Traffic by the Numbers

8.  What This Means for Real Estate in Argyle, Northlake, and Justin

9.  The Alliance Corridor Context

10. Straight Talk: What You Should Do Next

11. Frequently Asked Questions

FM 407 isn’t just a road. It’s the primary east-west connector linking some of the fastest-growing communities in North Texas — Argyle, Northlake, and Justin — to I-35W and the broader DFW Alliance Corridor employment base.

For tens of thousands of families who chose these communities for their top-rated schools, master-planned neighborhoods, and quality of life, FM 407 is the daily reality between home and everything else. And for years, that reality has meant congestion, S-curves, and an infrastructure footprint that was built for a much smaller population than what’s here today.

The growth didn’t wait for the road. The road is now catching up.

Let’s start with what’s actively under construction, because this is the relief that’s coming fastest.

In January 2026, the Denton County Commissioners Court approved a contract with Ed Bell Construction Company for $2,058,939 to begin immediate intersection improvements at FM 407 and I-35W. Construction began in February 2026 and is expected to take approximately 100 days to complete — meaning completion is projected for late spring or early summer 2026.

This project — officially called the FM 407 at I-35W Micro Breakout — includes:

•       Right-turn lanes added on the west side of FM 407 at I-35W

•       A southbound right-turn lane onto westbound FM 407 from I-35W

•       A northbound right-turn lane onto eastbound FM 407 from I-35W

•       Drainage improvements

•       Vehicle deflection walls at the FM 407 and I-35W overpass

•       Updated pavement markings

It won’t solve everything. But it will meaningfully reduce the chokepoint that has frustrated drivers at this intersection for years, and it will do so while traffic continues to flow through the area during construction.

Denton County Judge Andy Eads put it plainly: “We know this has been a difficult situation for residents who use this route and, though improvements to FM 407 are in our long-term plans, we needed to take action sooner than later.”

How did we get here? Denton County has been working on FM 407 improvements since 2019. The original breakout project at I-35W was targeted for a September 2025 construction start — a date that slipped due to a right-of-way acquisition process that took 15 months instead of the expected three. Rather than wait further, the county stepped in with this interim micro project, funded entirely by Denton County, not TxDOT.

That distinction matters. Denton County transportation consultant John Polster was direct about it: “We know the breakout of the ultimate is delayed because of things out of our control, we know the ultimate is delayed because of things out of our control, but the interim of the interim is in our control.”

That’s the kind of leadership that gets things done in a growing region.

The micro breakout is the appetizer. Here’s the full meal.

TxDOT’s ultimate FM 407 project covers 11.5 miles from Bill Cook Road west of Justin all the way to FM 1830 at the Argyle/Bartonville border — touching residents in six cities and towns across the corridor.

The scope of the transformation is significant. The current road is a two-lane rural highway. The proposed project would reconstruct it as a six-lane urban divided road with:

•       Three eastbound and three westbound lanes

•       12-foot-wide travel lanes

•       18-foot-wide raised medians

•       12-foot-wide left-turn lanes

•       Curb and gutter drainage

•       A shared-use path and sidewalk accommodating pedestrians and cyclists

•       A completely new routed alignment between Northlake and Justin that bypasses the current S-curves

The right-of-way requirement — approximately 121 acres of new land — has already been identified. TxDOT has been in the process of notifying affected property owners and acquiring that right-of-way in the Argyle segment, where utility relocations from Cleveland-Gibbs Road to Gateway Drive are already underway.

Total estimated project cost: $235 million.

We are going to be straight with you here, because you deserve accurate information when you’re making real estate decisions.

The full FM 407 widening project is currently unfunded at the state level. TxDOT officials confirmed as recently as March 2026 that they are still working to identify funding and do not have a confirmed construction timeline. The construction letting process — when bids are solicited — is not anticipated to begin until 2028 at the earliest.

Here’s the layered timeline as it stands today:

•       Now through mid-2026: Micro Breakout construction at FM 407 and I-35W (funded, under contract, underway)

•       June 2026 (estimated): Environmental clearance for the broader FM 407 widening, which Commissioner Edmondson indicated could come as early as June 2026

•       Late 2027: TxDOT bidding process expected to begin for the Argyle segment (Cleveland-Gibbs Road to Gateway Drive)

•       2028: Broader construction letting anticipated for the full 11.5-mile project

•       Construction duration: Multi-year once funded and under contract

Why the delay at the state level? TxDOT operates under a “level-letting” cap that limits how much the agency can commit to construction projects in a given year. When that cap is reached, projects get pushed. FM 407 has been caught in that queue. The good news: Denton County has proactively funded planning, design, right-of-way acquisition, and early construction to stay ready the moment state funding becomes available.

In January 2026, Denton County approved more than $12.5 million for two local road projects — including the FM 407 breakout work at I-35W and a separate Lakeside Parkway widening in Flower Mound — specifically to keep the project moving and reduce the state’s timeline burden. Commissioner Edmondson framed it directly: “We have taken the initiative to help the state with this project by getting the initial set-up completed so that the FM 407 widening might be finished earlier.”

The county’s total investment to date, including engineering and advance work, already exceeds $5 million. They are not letting this sit.

One of the most significant — and least discussed — elements of the full FM 407 project is the proposed realignment between Northlake and Justin.

Today, FM 407 makes several sharp turns in this section, merging with FM 156 through a stretch of Justin before separating again. The proposed project would create a new alignment that completely bypasses these S-curves, cutting out the FM 156 merge entirely and providing a direct, straight connection between Northlake and Justin.

The right-of-way for this new alignment is approximately 140 feet wide — wider than the existing road in most places — and the realignment is designed to also redirect FM 407 around Justin’s Old Town, which local leaders view as critical to preserving the character of the city’s historic core while accommodating regional traffic growth.

For Treeline residents in Justin and Pecan Square residents in Northlake, this realignment is the change that will most directly transform daily commute options once completed.

FM 407 doesn’t exist in isolation. A connected TxDOT project — construction of frontage roads along I-35W through Denton County — is moving through planning on a parallel track, and the two projects are designed to work together.

TxDOT is planning frontage roads along I-35W in two segments:

•       Segment 1: From 0.7 miles south of FM 407 to FM 2449 — estimated cost $260.7 million, with $213 million in funding already secured as of late 2025. Bidding process targeted for December 2027.

•       Segment 2: From FM 407 to Dale Earnhardt Way in Northlake — estimated cost $259.4 million. Design plans were scheduled for completion in January 2026. Bidding process also targeted for December 2027.

These frontage roads will separate local traffic from through traffic on I-35W, improve access to neighborhoods and businesses along the corridor, and reconstruct grade separations at cross streets. Combined with the FM 407 widening, they represent a comprehensive infrastructure investment in the corridor’s long-term mobility.

The full scope: two frontage road projects totaling more than half a billion dollars, in addition to the $235 million FM 407 widening. This corridor is receiving serious, sustained infrastructure attention.

The growth driving all of this investment isn’t speculative. TxDOT’s own traffic count data tells the story:

•       West of FM 407 and I-35W: Daily trips grew from 14,326 in 2019 to 21,051 in 2024 — a 47% increase in five years

•       East of FM 407 and I-35W: Daily trips grew from 12,216 to 15,325 in the same period — a 25% increase

•       FM 407 and I-35W in Corral City: 18,033 vehicles per day

•       FM 407 and US 377 in Argyle: 11,743 vehicles per day

•       FM 407 and FM 156 in Justin: 6,620 vehicles per day

These numbers reflect 2023 traffic counts. Given the pace of residential development across Harvest, Pecan Square, Treeline, and the surrounding area since then, current volumes are almost certainly higher.

The infrastructure need is real, documented, and growing. The investments being made — even before full funding is secured — reflect that reality.

Here’s where we bring it home.

For buyers considering this corridor: The FM 407 situation is a known factor — and it’s actively improving, not deteriorating. The micro breakout at I-35W brings near-term relief. The longer-term widening and realignment will transform connectivity for the entire corridor once funded and constructed. Buying now, before that transformation is complete, means getting in at today’s prices with tomorrow’s infrastructure on the horizon. For families relocating to North Texas from out of state, this corridor consistently ranks among the strongest long-term value plays in the entire DFW Metroplex.

This is a pattern we’ve seen play out across the Alliance Corridor repeatedly. Infrastructure investment follows — and then accelerates — residential growth. The communities closest to FM 407 improvements are positioned to benefit from both the quality-of-life improvement and the increased buyer demand that typically follows major infrastructure upgrades.

For sellers: Traffic and road conditions are consistently cited by buyers as a quality-of-life concern in this corridor. Being able to speak knowledgeably about the specific improvements underway — not just “they’re working on it,” but the actual scope, timeline, and funded phases — is a differentiator in your listing conversations. Buyers with accurate information make more confident decisions, and more confident buyers move faster.

For families choosing between communities: School quality, community amenities, and commute friction are the three most common factors we hear in relocation conversations. FM 407 improvements directly address commute friction. Pair that with Argyle ISD’s continued performance, Northlake’s expanding amenity base — the StarCenter Multisport just opened, MP Materials’ $1.25 billion campus is bringing 1,500+ jobs — and Justin’s rapidly developing commercial sector, and the fundamentals of this corridor are as strong as they’ve ever been.

The road is catching up. The communities it serves are already exceptional.

FM 407’s transformation doesn’t happen in a vacuum. It’s part of a broader infrastructure narrative across southern Denton County that includes:

•       Landmark by Hillwood — Denton’s 3,200-acre, $10 billion master-planned community at I-35W and Robson Ranch Road, with first homes expected summer 2026 and Denton’s first H-E-B under construction on site

•       Children’s Health StarCenter Multisport Northlake — The Dallas Stars’ 225,000-square-foot facility at Highway 114 and Chadwick Parkway, which opened March 31, 2026, and is projected to draw 1.3 million visitors annually

•       MP Materials’ $1.25 billion manufacturing campus — Announced for Northlake near Texas Motor Speedway, with more than 1,500 jobs and potentially the largest private commercial investment in Denton County history

•       Crestview in Justin — A proposed 1,244-acre development northwest of Treeline that could bring nearly 5,000 homes, a major grocer, and 137 acres of parkland to Justin’s west side

Each of these projects increases the urgency and the long-term value case for FM 407 infrastructure investment. More residents, more workers, more visitors — and a road network being upgraded to serve them all.

This is what a region in the middle of a generational growth cycle looks like. Infrastructure follows intention. And the intention here — from the county, the state, and private developers — is clear.

We’ve covered a lot of ground. Here’s how to think about it if you’re in the middle of a real estate decision right now.

If you’re buying: Don’t let FM 407’s current condition be the reason you pass on a community that checks every other box. The near-term improvement is underway. The long-term transformation is funded at the planning level and moving toward construction. What you’re experiencing today on that road is not what it will look like in three to five years — and the homes you’re considering will reflect that improvement in value.

If you’re selling: Price and presentation are always first. But your agent should be able to speak to infrastructure context the way we just did — not with vague promises, but with specific projects, funded phases, and realistic timelines. That’s the difference between an agent and a trusted advisor.

If you’re still deciding on a community: Bring your specific situation to us. We live and work in this corridor — it’s our home, not just our market. Edson and Paige have purchased five new construction homes along the Alliance Corridor, including our current home in Pecan Square. We’re not selling you on a zip code — we’re sharing what we know from living it. If you’re relocating to North Texas and trying to decide between communities, new construction in Argyle, new construction in Northlake, and new construction in Justin along the FM 407 corridor offer some of the best value in the DFW market right now.

Start a conversation with us.

Alliance Corridor Community Guides

Landmark by Hillwood: Denton’s $10 Billion Master-Planned Community

Pecan Square by Hillwood: Complete Community Guide

Treeline by Hillwood: Justin’s Newest Master-Planned Community

Harvest by Hillwood: Complete Community Guide

Alliance Corridor Development Coverage

Children’s Health StarCenter Multisport Northlake Is Open

MP Materials’ $1.25B Manufacturing Campus: What It Means for Northlake

Why the Alliance Corridor is North Texas’ Fastest-Growing Real Estate Market

Official Sources

TxDOT FM 407 Project Information

Denton County Road Projects

Cross Timbers Gazette

Community Impact — Argyle/Northlake