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San Antonio Area Freeway System
Loop 1604 North Expansion Program

This page last updated July 18, 2024

Project location mapAn expansion of Loop 1604 from Bandera Rd. to I‑35 North has been in the works since the beginning of this century. Due to severe funding limitations for much of the past two decades, those expansion plans necessarily included tolled lanes, and a series of issues over the years repeatedly delayed the project.

In the past decade, increases in state highway funding and the resulting deprecation of tolling have resulted in the toll component of this expansion being removed. Instead, plans now are to expand Loop 1604 by adding two non-tolled general-purpose lanes and one HOV lane in each direction. This project will also replace the obsolete cloverleaf interchange at I‑10.

Below is complete information about the latest status of this project.


On this page:

Project description

This massive $1.3 billion project will expand Loop 1604 from Bandera Rd. to I‑35 from two general-purpose lanes in each direction to five non-tolled lanes in each direction (four general-purpose lanes and one HOV lane.) Note that some sections may have three, five, or six general-purpose lanes depending on the traffic volume, geometry, or available right-of-way at that particular location, but typically the corridor will have four general-purpose through lanes each way.

Loop 1604 cross-section

Planned typical Loop 1604 cross-section from Bandera Rd. to I‑35

This project will also replace the overburdened and obsolete I‑10/Loop 1604 cloverleaf with a fully-directional "Texas stack" interchange. Initial funding was only sufficient for the first two flyovers in the new interchange; however, the Texas Transportation Commission approved additional funding in August 2019 to complete the entire interchange in a single project.

The proximity of the interchange flyover terminals to nearby exits will require a complete re-working of nearly all of the entrance and exit ramps in the vicinity, which in many cases will dramatically change access to adjacent streets and businesses.

Rendering of new I-10/Loop 1604 interchange

Rendering of new I‑10/Loop 1604 interchange
(Courtesy of TxDOT)

"The fidget spinner"
Plans also call for the signalized access road intersections below the interchange to be replaced with a unique intersection consisting of four partial roundabouts — or one large stretched roundabout, depending on how you look at it — that engineers have nicknamed "the fidget spinner." While there are other places with a series of roundabouts or partial roundabouts, this is believed to be the first intersection with this specific configuration.

Two sets of new elevated collector-distributor roads on both I‑10 and on Loop 1604 will allow access road traffic headed straight through the interchange to completely bypass the lower-level intersections.

A completely redesigned VIA Park & Ride will remain in the middle of the fidget-spinner.

Schematic for new VIA Park & Ride

Schematic of lower-level "fidget spinner" intersection
Blue line shows the path for a north-to-west left turn. Outer right-turn lanes and turnarounds, both of which bypass the partial roundabouts, are indicated. Not shown are the planned access road bypass flyovers, which will allow access road traffic going straight through to pass over the fidget spinner and bypass it entirely.

The Blanco Rd. Diverging Diamond Interchange project, which had previously been planned to be a separate project, has been rolled into the I‑10 to US 281 segment of this project.

New interchange connectors at I‑35 are being built as part of the I‑35 Northeast Expansion (NEX) project. The improvements east of Green Mountain Rd. planned as part of the Loop 1604 Expansion project are designed to integrate with those connectors.

Finally, this project will make numerous entrance and exit ramp revisions and access road improvements. One of the more notable ramp improvements will be to add a dedicated westbound exit ramp to Hausman Rd. and a dedicated eastbound entrance ramp from Hausman Rd. As mentioned earlier, the locations of the touch-down points for the elevated connectors in the revamped I‑10/Loop 1604 interchange will also necessitate several ramp changes on both Loop 1604 and on I‑10 in the vicinity of the interchange in order to reduce conflicts and smooth-out traffic flow.

This project — quite remarkably — will be built almost entirely within the existing right-of-way. This is because planners of the original Loop 1604 back in the 1960s acquired enough right-of-way for this eventuality.

Funding and contracting constraints will require the project to be divided into multiple phases. The first four phases from Bandera Rd. to Redland are now under construction with substantial funding coming from the Texas Clear Lanes project, an initiative of the Texas Transportation Commission to help advance projects to reduce congestion in the state's five major metro areas. The remainder of the expansion from Redland to I‑35 is currently broken into two phases with tentative funding identified.

Map of Loop 1604 Expansion phases

Project phases

Phase 1: Bandera Rd. to I‑10

This phase will include the following major components:

Phase 2: I‑10 to US 281

This phase will include the following major components:

Phase 3: Loop 1604/I‑10 interchange

This phase will include the following major components:

  • All eight new flyover direct-connectors between I‑10 and Loop 1604. (The top two flyovers will be about 125' above the ground!) The existing cloverleaf interchange will be demolished in phases as the corresponding new connectors are completed.
  • Six general-purpose freeway mainlanes (i.e. three in each direction) will be carried through the interchange on both I‑10 and Loop 1604, and I‑10 will have extra pavement in its median for a future extension of the HOV lanes south from their current terminus near La Cantera Blvd.
  • Flyover access road bypasses on both I‑10 and Loop 1604. These will allow through traffic on the access roads to bypass the lower level intersections.
  • Replacement of the signalized access road intersections with a continuous flow intersection consisting of four partial roundabouts ("the fidget spinner".)
  • New access road turnarounds for both directions of I‑10.
  • Reconstruction of the VIA Park & Ride. 
  • Relocation of the westbound exit to La Cantera Blvd. including an intersection flyover bypass at La Cantera Blvd. to allow traffic to access the northern entrances to The Rim without going through the signal at La Cantera Blvd.
  • The eastbound exit to UTSA Blvd. will be permanently removed due to its proximity to the new entrance from Loop 1604. Traffic on I‑10 wanting to reach UTSA Blvd. will exit at a new exit in the Loop 1604 interchange and continue on the access road. Traffic on Loop 1604 wanting to reach UTSA Blvd. will have to exit onto the access road on Loop 1604 before reaching I‑10, then turn south (eastbound) onto on the I‑10 access road to reach UTSA Blvd.
  • The westbound entrance ramp from UTSA Blvd. will also be permanently removed. Traffic wanting to enter I‑10 or Loop 1604 will continue on the access roads to the next available entrance ramp. This is necessary to smooth traffic flow on the approach to the new Loop 1604 exit, which will be located closer to UTSA Blvd. than the current one.
  • The westbound entrance ramp from De Zavala Rd. will be slightly relocated and lengthened.

Phase 4: US 281 to Redland Rd.

  • Status: Construction underway (11% complete)
  • Timeline: Construction started in April 2024 and is expected be completed in late 2027
  • Construction cost: About $135 million

This phase will include the following major components:

  • Multiple new non-tolled general-purpose freeway lanes plus one high-occupancy vehicle (HOV) lane in each direction. The number of lanes varies throughout this section due to the interchange at US 281:
    • Through the interchange, there will be three general-purpose lanes and one HOV lane in each direction.
    • Heading eastbound, the two lanes from US 281 will be added, making five lanes plus the HOV lane. These six lanes will then begin to taper down to two beginning at the Bulverde exit. The right lane will become an exit-only lane at the Bulverde Road exit. The remaining right lane will then end (merge left) shortly past the Bulverde exit. That will be followed by the HOV lane ending (merge right) a short distance later. Finally, the remaining right lane will end (merge left) shortly before the entrance ramp from Redland Rd. While this is likely to be a significant bottleneck, it is temporary until the next phase to the east (Phase 5) is done.
    • Heading westbound, the existing two lanes will widen to four lanes and quickly to five lanes (four general-purpose lanes plus an HOV lane) shortly past the Redland Rd. exit. An additional general-purpose lane will be added from the Redland Rd. entrance ramp. The two right lanes will then become exit-only lanes to US 281, leaving the three general-purpose lanes plus the HOV lane to continue through the interchange.
  • The existing eastbound exit to Bulverde Rd. will be expanded to two lanes (right lane exit-only as discussed above, and an exit/straight option lane.)
  • This phase will also expand the right turn from the westbound access road onto Stone Oak Pkwy. to two lanes.
  • West of Gold Canyon Rd., there will be conventional double-sided mast-arm street lights on the center barrier. East of there will have high-mast lighting.

Future phases

The remainder of the expansion from Redland Rd. to I‑35 is currently broken into two segments with the following tentative start dates:

  • Phase 5: Redland Rd. to Judson Rd. - Late 2024 (accelerated from late 2025)
  • Phase 6: Judson Rd. to I‑35 - Late 2025 (accelerated from late 2028)

How this project will help

As anyone who regularly drives Loop 1604 knows, this corridor experiences frequently-recurring congestion due to traffic volumes regularly exceeding the capacity of the road. Adding additional lanes provides the obvious benefit of increasing capacity and thus reducing congestion. Modeling shows that when the project is completed, the corridor should experience continuous free-flow conditions, including during morning and evening peak periods (barring incidents, of course.)

Projections for 2045 show that traffic volumes will nearly double. Even so, the modeling shows that by 2045 with the planned expansion, the corridor should still generally see travel times of 25-30% below than today's with the exception being the eastbound morning peak, which could again be at or near current travel times. However, that travel time modeling is for the entire corridor end-to-end; localized sections should still see improved travel times.

HOV lanes are now being added to major freeway expansion projects in San Antonio where feasible. The intent is to encourage carpooling and the use of mass transit. Each person that opts to do so is one less vehicle on the freeway, which helps to reduce congestion and pollution for everyone. Furthermore, HOV lanes help to "future-proof" a corridor by building-in lanes today that can someday be used for new transportation options such as autonomous vehicles. For more information about local HOV lanes, see the HOV lanes page.

The current cloverleaf at I‑10 is obsolete and unable to handle current traffic loads. While this cloverleaf was more than adequate when it was built 40 years ago and for 20-year planning horizon it was designed for, cloverleafs in general are now considered passé in heavy traffic areas as they simply cannot handle contemporary traffic volumes — as this interchange demonstrated during the past decade or so — and nearly all existing cloverleafs in San Antonio are being replaced as a result. Additionally, the weaving maneuvers in a cloverleaf are a major safety issue. The new "Texas stack" interchange here should fully alleviate those issues.

The "fidget spinner" intersection below the I‑10/Loop 1604 interchange will remove the signalized intersections there and should provide a more continuous flow of traffic. A traffic study showed that much of the traffic using the current "box" intersection there was doing so to avoid congestion above, so when the new interchange is complete, the traffic volumes in those access road intersections should be appreciably reduced, and modeling shows the partial roundabouts should be able to handle the expected traffic there more efficiently than signals. The new intersections will also be better positioned to accommodate the driveways in the immediate vicinity.

Finally, the assorted ramp revisions should provide better traffic flow between the mainlanes and access roads.



Click on one of the letters on the image below to open the detailed schematic for that section of the project. The base schematics are from TxDOT with my own annotations added to help clarify and explain the various elements. Each schematic will open in a new window that you can scroll and zoom.

Changes to Phase 1
These are the schematics presented to the public in September 2020. However, the construction bid plans for the Bandera Rd. to I‑10 segment show some significant changes from the schematics I have here. Most of the changes are at the southwestern end of the project and are shown in blue annotations on the "A" schematic, and a snippet from the bid plans that shows the changes is included. Here is a summary of the major differences:

  • The mainlane widening was originally proposed to begin/end just south of Bandera Rd. However, that has now been moved to just south of Hausman, i.e. the mainlanes will remain mostly as they are today south of Hausman.
  • The eastbound access road between Bandera and Hausman were planned to be widened, but that has been dropped for now, and the westbound access road will be expanded to three lanes instead of four.
  • The HOV lanes on this segment will not be opened as part this project. The pavement for the lanes will be laid, but the lanes will not be marked and will be barricaded until the later phases are complete. This is because it is not feasible to provide a proper transition area for the ends of the HOV lanes near I‑10 for the short period between when this project is completed and when the interchange will be completed.

Notes for Phases 2 and 4
These are the schematics for the entire "master plan" between Bandera Rd. and I‑35. However, because the sections east of US 281 will be completed later, the widening done in Phase 2 will need to taper in order to transition to the existing four-lane section of 1604 east of US 281; this tapering will happen in the vicinity of the Stone Oak Pkwy. overpass (details discussed in the "Phase 2" section above), so the lane configurations between Stone Oak Pkwy. and US 281 shown in the schematic below will be built as part of Phase 4.

The same situation will happen at the eastern end of Phase 4 — there will be a temporary tapering of the lanes between Redland Rd. and Bulverde Rd. as discussed in the "Phase 4" section above pending the completion of Phase 5. The lane configurations shown in the schematic for that segment are what will exist when Phase 5 is complete.

Finally, as with Phase 1, the HOV lanes for Phase 2 will not be opened when the rest of the work for that phase is complete. The pavement for the lanes will be laid, but they will not be marked and will be barricaded until the interchange at I‑10 is complete. This is because it is not feasible to provide a proper transition area for the ends of the HOV lanes near I‑10 for the short period between when this project is completed and when the interchange will be completed.

Click on one of the letters on the image above to open the detailed schematic for that section


I put together some videos that discuss Phases 1 and 2 in-depth including a virtual flyover where I explain the new lane and ramp configurations:

Phase 1 - Bandera Rd. to I‑10

Phase 2 - I‑10 to US 281

Phase 3 - Loop 1604/I‑10 interchange


  • Will this project be tolled?
    No. Although earlier versions of this project proposed adding two tolled managed lanes in each direction, funding was secured to remove the toll component. Instead, two non-tolled mainlanes in each direction plus an HOV lane will be added.

  • Why didn't they originally build this stretch of Loop 1604 with more than two lanes each way?
    The current Loop 1604 between I‑10 and I‑35 was planned more than 40 years ago to upgrade the original two-lane farm road there at that time to the four-lane freeway that's there today — quadrupling the number of lanes. Loop 1604 between Bandera Rd. and I‑10 was planned around 1990 and also was a similar upgrade from the existing two-lane farm road.

    When planning a road, engineers look at the projected traffic volumes about 20 years out, and in both cases, those projections showed that four lanes would be sufficient. Indeed, significant recurring traffic congestion didn't develop until the 15 to 20 year mark, which shows the validity of the planning done. Twenty years is the accepted planning horizon because that's the length of time before a road will need major repairs and upgrades simply due to age (i.e. the road's expected lifespan), and because that's the length of time that any traffic projections can be considered even remotely reasonable. Nobody has a crystal ball, so traffic projections are "educated guesses" based on past growth and the best data available for future development in an area, and road capacity is always theoretical — many other factors other than just the number of lanes affect congestion levels. But as a steward of taxpayer dollars, TxDOT cannot spend more than they can empirically justify, a policy I'm sure most taxpayers support to prevent "pork" projects. And spending on extra lanes that may or may not be needed in the future takes away funding for other needed projects.

  • Why haven't they added more lanes to Loop 1604 North before now? Don't they know how bad the traffic is?
    Of course they've known how bad the traffic is, and plans had been in the works to expand Loop 1604 from Bandera Rd. to I‑35 for two decades. However, such an expansion is a very expensive project, with estimated costs approaching $1 billion. Due to substantial funding shortages that began in the early 2000s, TxDOT was required to incorporate tolling to pay for mega projects like this. With local opposition to tolling and the melodrama over a similar plan on US 281 that delayed that project for over a decade, the plan for 1604 had to be reworked several times. Additionally, because of the project's location over the Edwards Aquifer Recharge Zone, an extensive and lengthy environmental study was undertaken. When new funding mechanisms became available and the toll component was removed from the project, the project had to be redesigned yet one more time. All of those delays added-up.

  • What are the green slats on top of the center barrier for?
    This is an anti-glare screen to block the headlight glare from oncoming vehicles. It was installed when there were multiple lane shifts which caused headlights to shine directly into oncoming traffic. They are scheduled to be removed at the end of the project when they no longer will be needed.
Anti-glare screen on Loop 1604

Anti-glare screen atop center barrier near Babcock Rd.
(Photo by Brian Purcell)

Project history

In the mid to late '80s and early '90s, Loop 1604 was upgraded from a two-lane farm road to a four-lane freeway between I‑10 West and I‑35 North. Subsequent projects in the early and mid '90s extended the freeway to Kitty Hawk Rd. on the east and to Braun Rd. on the west. Since that time, a tremendous amount development has taken place along the 1604 corridor, and traffic counts all along 1604 have increased dramatically. In fact, 13 of the top 20 locations for traffic growth in Bexar County between 1990 and 2016 were along 1604 North, with the location just north of Bandera Rd. showing growth of almost 1000%. Meanwhile, Loop 1604 has struggled to keep up with the explosion of traffic. Several upgrades to the western section south of Braun Rd. have been completed since 1999. However, plans to expand the northern arc from Bandera Rd. to I‑35 North languished for nearly two decades due to several reasons including insufficient funding and delays to required environmental studies. Read on for a more in-depth history of the various machinations this project has gone through.

Loop 1604 earmarked for managed lanes
The first expansion plans for Loop 1604 North were developed around 2000. However, in the early years of this century, construction costs nationwide experienced a sudden, staggering increase. This resulted in severe funding shortages for highways as projected costs exceeded project budgets. Officials sought new methods for funding, with tolling becoming the primary option. To that end, the Texas Transportation Commission (TTC), at the governor's behest, ordered in December 2003 that "controlled-access mobility projects in any phase of development or construction must be evaluated for tolling. This includes new location facilities and increased capacity projects such as adding additional main lanes or constructing new main lanes." This order compelled TxDOT to evaluate all planned Loop 1604 freeway projects for possible tolling. The evaluation showed that the anticipated traffic volumes along 1604 made it viable for tolling, so per the TTC's order, the projects were reclassified as toll projects, and plans were made to incorporate tolled managed lanes into the designs for an expansion from Culebra Rd. to I‑35 North. This, along with a project on US 281 North, would constitute a local toll "starter system."

Question mark sign
What is a managed lane?

A managed lane is a lane where the operational strategies of the lane are adjusted in real-time to ensure that the lane remains free-flowing, thus providing for a guaranteed travel time for users of the lane. For example, toll rates or vehicle occupancy requirements may fluctuate based on traffic conditions or time of day. Typically, managed lanes allow toll-free access for buses, carpools, and emergency vehicles, while single-occupancy vehicles (i.e. solo drivers) can use the lane by paying a variable-rate toll.

How is this beneficial? Besides providing a clear lane for public transportation and emergency vehicles and encouraging carpooling, it also gives solo commuters who want or need to get where they're going faster an opportunity to bypass congestion by paying a toll to use any excess capacity of the lane. Every motorist who opts to do so removes one more vehicle from the non-tolled lanes, which can help ease congestion. The resulting toll revenue helps to subsidize the road, saving scarce tax dollars for other needed projects.

Cintra-Zachary proposal
In 2005, a consortium consisting of local construction giant Zachary and the Spanish infrastructure company Cintra, who were working together on a bid to construct one of the now-defunct Trans Texas Corridor projects, submitted an unsolicited bid to TxDOT to build the Loop 1604 and US 281 toll projects in return for a 50-year lease to operate them. Because the bid had merit, TxDOT was required to fully evaluate it and then to accept any other bids for the projects. The Cintra-Zachary bid not only paid for construction and subsequent maintenance and operation of both roadways (which freed scarce state funding for other needed projects), it also paid a large franchise fee to the state that could also be used to fund other projects. Based on those merits, the Cintra-Zachary bid was accepted, and work started on the US 281 project in late 2005. A subsequent lawsuit over the 281 project resulted in TxDOT canceling the entire Cintra-Zachary contract, including the 1604 project.

ARMA takes over
In 2007, in light of mounting pressure from activists against toll roads being built and operated by private and mostly foreign corporations, the Legislature passed a moratorium on nearly all new privately-built and/or operated toll roads. The legislation required that local Regional Mobility Authorities be given the right of first refusal on toll projects in their jurisdiction. The Alamo Regional Mobility Authority (ARMA), which was established by Bexar County in 2003, subsequently opted to take control of both the 281 and 1604 projects and put forth a $1.8 billion plan to upgrade and expand the entire northern arc of Loop 1604 from Military Dr. on the west all the way over to I‑10 on the east. The required environmental study for that project was started and, during the scoping process for that study, the eastern boundary for the project was set at I‑35 North while the western boundary was extended south to US 90.

Southern US 281/Loop 1604 interchange connectors built
During the Great Recession, Congress approved a national economic "stimulus" plan in February 2009 that poured additional federal money into road construction projects. The Alamo Area Metropolitan Planning Organization (MPO) approved allocating most of San Antonio's share of the largesse for the first half of a 281/1604 interchange. That project built all four of the ramps connecting to 281 south of 1604, i.e. northbound 281 to both directions of 1604, and both directions of 1604 to southbound 281. The use of the federal funds allowed the ramps to be non-tolled. The Texas Transportation Commission (TTC) approved the state's share of the costs on March 5th, 2009. Construction began in early 2011 and was completed in early 2013. It had been determined that ramps connecting to 281 north of 1604 should not be built until lingering issues stemming from the lawsuits and associated environmental studies for 281 north of 1604 were resolved. Those ramps were subsequently completed as part of the first phase of the US 281 expansion project.

Eastern and western upgrades built
The TTC also approved using stimulus funds to expand Loop 1604 to a four lane divided highway from FM 78 to Graytown Rd. near Randolph AFB. That work was completed in September 2011. That same month, ARMA and TxDOT completed a package of short-term improvements — including two "superstreet" intersections — on Loop 1604 West between Braun and Culebra.

New funding for toll-free expansions
In January 2014, TxDOT and ARMA announced funding had been secured to expand Loop 1604's western arc from Braun Rd. south to US 90 using a mix of various local funding sources from the Advanced Transportation District and ARMA. However, this corridor was already included in the ongoing federal environmental study for ARMA's larger project from US 90 to I‑35. Since the funding for the western expansion was coming solely from state and local sources, it no longer was required to comply with federal environmental rules. Therefore, to avoid delaying those projects unnecessarily while the federal environmental study dragged on, the western segments were removed from that ongoing study and instead approved under a separate state environmental review. This had the adverse side effect of requiring the ongoing federal study to be re-scoped and re-started using the adjusted project limits, thus resulting in a substantial delay to that study and project.

Tolls still needed
During its session in early 2015, the Texas Legislature approved new funding sources for highways that reallocated approximately $2.5 billion from sales taxes and motor vehicle sales taxes annually to highways. At that time, it was projected that even the additional funding available to San Antonio from that new source would not be sufficient to fund this project, so the tolled managed lane component was kept in the plans.

Tolling depreciated
In late 2017, the governor and lieutenant governor directed the TTC to remove tolling from future projects. However, because Loop 1604 was already in local plans with tolling underpinning its funding, and because the projected funding for the area was still projected to be insufficient to cover its then-$800 million estimated cost, it retained its designation in local plans as a toll project. This was done because a viable funding source is required under federal rules in order for planning on a project to continue.

Toll component removed; TxDOT takes project back
In mid 2018, revised funding forecasts became substantially more favorable. In light of that, and with tolling deprecated statewide and all the other planned local toll projects already converted back to traditional funding, the MPO board voted to remove the toll component from this project, and ARMA relinquished the project back to TxDOT.

New non-toll plans released
In September 2020, TxDOT released the updated plans that removed the tolled managed lanes and replaced them with two additional non-toll general-purpose lanes and one HOV lane in each direction along with a redesigned interchange at I‑10.

Construction finally begins
In May 2021, with sufficient funding now in hand, construction on the first phase of the expansion, from Bandera Rd. to I‑10, began. Phase 2 started later that year, and Phase 3 began the following year. Phase 4 will start in early 2024.

Other sites of interest

TxDOT- Loop 1604 from SH 16 to I‑35 Open House