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San Antonio Area Freeway System
Loop 1604 North Expansion Project

This page last updated October 3, 2019


This project is currently in final design
The descriptions below are based on preliminary schematics and, as a result, some details may change before the project goes to construction. 

An 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. A series of issues over the years delayed the project. Recently, increases in state funding and the deprecation of tolling statewide 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

Current project plans

Project description
This massive $1 billion project will 
expand Loop 1604 from Bandera Rd. to I‑35 to four general-purpose freeway lanes in each direction plus an HOV lane in each direction. Note that some short sections may have more or fewer general-purpose lanes depending on the traffic volume, geometry, or available right-of-way at that particular location, but overall, the corridor will have four general-purpose lanes each way.

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

The project will also replace the overburdened and obsolete I-10/Loop 1604 cloverleaf with a fully-directional "stack" or "web" interchange. 
Earlier 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 flyovers to nearby exits will require a complete re-working of the ramps in the vicinity. Additionally, the I-10 mainlanes through the interchange will be expanded to allow the new HOV lane currently under construction on I-10 north of here to be extended south through the interchange where it will terminate (for now.)

Rendering of planned I-10/Loop 1604 interchange
(Courtesy of TxDOT)

Plans also call for the lower-level signalized access road intersections at that 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 locations with a series of roundabouts or partial roundabouts, this is believed to be the first intersection with this specific configuration. Two sets of elevated collector-distributor roads on I-10 and on Loop 1604 will allow access road traffic headed straight through the interchange to completely bypass the lower-level intersections. The VIA Park & Ride will remain in the middle of the fidget-spinner.

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 elevated collector-distributor roads, which will start at each end of the interchange and allow access road traffic going straight through to fly over the fidget spinner and bypass it entirely.

The Blanco Rd. Diverging Diamond Interchange project
, which was previously planned to be a standalone project, will now be rolled into this larger expansion project.

New interchange connectors at I‑35 will be built as part of the I‑35 Northeast Expansion (NEX) project.

Finally, the project will make several 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. 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 entirely within the existing right-of-way. (This is because planners in the past acquired enough right-of-way for this eventuality.)

Funding and contracting constraints will require the project to be divided into multiple phases. Funding is currently available for the first three phases running from Bandera Rd. to US 281. The remainder of the expansion from US 281 to I‑35 is currently unfunded, but TxDOT and the MPO are working to obtain funding to complete the expansion. 

The current anticipated project schedule is as follows:

  • Bandera Rd. to I-10: Start early 2021
  • I-10 to US 281: Start mid 2021
  • I-10/Loop 1604 interchange: Start early 2022
  • US 281 to I-35: Unfunded, so no current timeline

Previously, it was reported that the segment from US 281 to Redland Rd. would start construction in 2022. However, as engineers further fleshed-out the projects west of US 281, it was determined that the estimated costs for those would not leave sufficient funding from the $650 million currently available for this project for the US 281 to Redland segment. That could change as further cost estimates or the actual project bids come in later.

It is currently estimated that the first three projects will be complete by 2025. 

In the short-term before this project starts, TxDOT is implementing some small "quick-fix" type projects to help relieve some critical bottlenecks including ramp reversals at Bandera Rd. and at Bulverde Rd.

How this project will help
As anyone who regularly drives in this corridor knows, this route 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 complete around 2025, 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, 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 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.

The current cloverleaf at I-10 is obsolete and unable to handle current traffic loads. Cloverleafs in general are now considered passť in heavy traffic areas as they simply cannot handle contemporary traffic volumes, and all cloverleafs in San Antonio have been or will be replaced. Additionally, the weaving maneuvers in a cloverleaf are a safety issue. The new "stack" or "web" interchange here should fully alleviate those issues.

The "fidget spinner" intersection below the I-10 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 the lower-level intersections should be appreciably lower, 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 various ramp revisions along the route 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 schematics 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. These are the schematics presented to the public in September 2019 and are still considered preliminary and subject to change.


  • Will this project be tolled?
    No. Although earlier versions of this project proposed tolled lanes, funding was secured to remove the toll component. Instead, non-tolled express lanes and HOV lanes will be added.

  • Why didn't they originally build Loop 1604 between Bandera and I-35 with more than four lanes?
    Loop 1604 between I-10. and I-35 was planned 35 years ago and was an upgrade from a two-lane rural road to the four-lane freeway that's there today-- a dramatic increase in capacity at the time. Loop 1604 between Bandera and I-10 was planned around 1990 and also was an upgrade from a two-lane rural road. Planners 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. An expansion has been planned for a while now but has been delayed (see next point.) 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 projections can be considered even remotely reasonable. Nobody has a crystal ball, so traffic projections are "educated guesses" based on the best data available for future development in an area and past growth, 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 projects that are needed today.

  • Why haven't they added more lanes to Loop 1604 North before now? Don't they know how bad the traffic is?
    Plans have been in the works to expand Loop 1604 from Bandera to I-35 for well over a decade. However, such an expansion is a very expensive project-- 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 drama over a similar plan on US 281 that delayed that project for over a decade, the plan for 1604 has had to be reworked several times. Additionally, because of the project's location over the Edwards Aquifer Recharge Zone, an extensive and lengthy Environmental Impact Study (EIS) was undertaken. With new funding mechanisms now in place and tolling deprecated, the toll component has since been removed from the project. This required the project to be redesigned yet again.

  • I will not use the HOV lane, so it won't benefit me. My taxes shouldn't pay for something I won't use.
    Even if you don't use the HOV lane, you will still get the benefit of it in that every vehicle that uses the HOV lane is one or more vehicles that won't be in the general-purpose lanes, thus reducing congestion there. We all pay taxes for many things we don't use or directly benefit from but that benefit everyone generally. Don't forget that the people who will use the HOV lanes are also taxpayers.

  • Instead of an HOV lane, another general-purpose lane would provide more capacity.
    Yes, having an additional general-purpose lane in place of an HOV lane would provide more unrestricted capacity. But the benefit would be short-lived because that extra lane will soon also become congested, and this likely will be the last expansion of this corridor for at least several generations. With an HOV lane, planners build-in a corridor that can be used now and well into the future to move more people per vehicle through the corridor, people who won't be clogging the general-purpose lanes in their single-occupancy cars. Freeway corridors are more than just pathways for vehicles-- they're high-capacity transportation corridors that need to be considered not only for their ability to move vehicles, but also their ability to move people. These two purposes can coexist and HOV lanes are a way of doing that. A new general-purpose lane, while providing immediate gratification, is myopic in the long-run; HOV lanes reflect a more sophisticated long-term planning desired by many citizens. 

  • Nobody wants HOV lanes.
    That's simply not true. Of the over 3,500 respondents to the recent SA Tomorrow transportation planning survey, 76% either agreed or strongly-agreed that HOV lanes should be an important part of San Antonio's transportation future. Anecdotally, the author of this website attends many public meetings for transportation projects and has consistently heard broad-based citizen support for HOV lanes.

  • Why build an HOV lane here when there aren't any others in San Antonio?
    The inclusion of HOV lanes in freeway projects is a recent change in local transportation planning policy and this project was in development when that policy was put into effect, so it was included in the project. If completed as planned, this could be the third HOV lane in San Antonio. The first two are already under construction on I-10 West and on US 281 North, and HOV lanes are also planned as part of the I-35 North Expansion (NEX) project. Furthermore, planners are already considering how to continue the I-10 and US 281 HOV lanes inside 1604, and HOV lanes will be included in the expansion of I-10 between Leon Springs and Boerne. This piecemeal approach to building HOV lanes is actually quite common. Remember that San Antonio's freeway system started with a short section of I-10 between Woodlawn and Culebra that provided no significant connectivity but was part of a bigger plan. "Rome wasn't built in a day."

  • What will be the requirements to use the HOV lanes?
    It is expected that the HOV lane will be open to vehicles with two or more passengers (HOV 2+), transit vehicles, motorcycles, and emergency vehicles. The HOV lanes will operate full-time.

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 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 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 have been completed since 1999. However, plans to expand the northern arc from Bandera Rd. to I‑35 North have been stalled for several reasons including insufficient funding and delays to required environmental studies. Below is 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 2000s, construction costs experienced a sudden, staggering increase. This resulted in severe funding shortages for highways. Officials sought new methods for funding, with tolling becoming the main new tool. 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 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."

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 way 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 toll-free lanes which can help ease congestion. The resulting toll revenue helps to subsidize for 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, which 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 toll-free. The Texas Transportation Commission (TTC) approved the state's share of the costs on March 5th, 2009. Construction began in early 2011 was completed in early 2013. It was 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 are now being built 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 the 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.

Other sites of interest

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

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This page and all its contents are Copyright © 2019 by Brian Purcell

The information provided on this website is provided on an "as-is" basis without warranties of any kind either express or implied.  The author and his agents make no warranties or representations of any kind concerning any information contained in this website.  This website is provided only as general information.  The author expressly disclaims all liability with respect to actions taken or not taken based upon the information contained herein or with respect to any errors or omissions in such information.  All opinions expressed are strictly those of the author.  This site is not affiliated in any way with any official agency.