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San Antonio Area Freeway System
PROJECT INFO: Loop 1604 from Culebra to Potranco

This page last updated September 20, 2019


Project locationLocation
Loop 1604 from Culebra Rd. to Potranco Rd.

Construction substantially complete.

This project upgraded Loop 1604 at this location from a four-lane divided highway to a four-lane, toll-free freeway. This included adding
overpasses at Wiseman Blvd., Military Dr. West, and Potranco Rd. (FM 1957), continuous access roads, and entrance and exit ramps. The discovery of a sensitive karst feature along the western edge of the right-of-way between Wiseman and Military necessitated a short bow in the corridor. Otherwise, the expansion was completed by converting the existing northbound lanes to the northbound access road, converting the existing southbound lanes to northbound expressway lanes, and constructing the remaining lanes (southbound expressway and access road.) Unbeknownst to most motorists, the previous divided highway was originally designed to eventually be expanded to a freeway as described above; this helped reduce costs, expedited the work a bit, and minimized disruption to traffic.

The cost of this project is $62.5 million and is being paid for with local funds from the Advanced Transportation District as part of the larger $825 five-year regional transportation plan announced in January 2014.

This project and an adjacent project extended the Loop 1604 freeway all the way to US 90.

How this project will help
Staggering ongoing growth in this area of San Antonio necessitated upgrading this roadway. The new freeway lanes with overpasses at the signalized intersections allows for continuous free-flowing traffic through the corridor.
The four freeway lanes are anticipated to handle the projected traffic in this corridor for the next 20 years.

The official groundbreaking occurred on September 12, 2016. Construction began in October 2016 and estimated completion is mid 2019.
Click here for the latest status report on this project.

The southbound mainlanes opened on April 18, 2019. The northbound mainlanes opened on May 25, 2019.


  • Why are the new sections of Loop 1604 only four lanes? It needs to be six lanes or more.
    A lot of people see the congestion on Loop 1604 North and assert that this stretch needs to be wider than four lanes (i.e. two lanes in each direction) to start with. However, this stretch of Loop 1604 carries less than a third of the traffic that most sections of Loop 1604 North do (34,000 vehicles per day at Potranco vs. 123,000 at Bandera.) That current volume, and the projections for the next 20 years, indicate that four lanes should be adequate. 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. Will this section experience congestion before 20 years? Maybe. 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. Furthermore, 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 corruption. And spending now on extra lanes that may or may not be needed in the future takes away funding for other projects that are needed today.

  • Why is there a curve in the corridor between Kilmarnoch and Reed when it used to be straight?
    A sensitive karst feature with possible endangered species was discovered within the right-of-way where the southbound mainlanes and access road would have been. As a result, TxDOT had to mitigate the impact of the road. The least expensive way to do that was to simply go around it; this resulted in the bowing of the road at that location. (See the schematic below for a view of the area in question.)

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

(Note: the schematic is somewhat large and may take a few seconds to open.)



Below are driver's view videos of the new lanes shortly after opening. Note that these videos show both this project as well as the adjacent project to the south.

Loop 1604 southbound from SH 151 to US 90

Loop 1604 northbound from US 90 to SH 151

Other sites of interest
TxDOT - Loop 1604 from FM 1957 to FM 471

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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.