The Texas
Highway Man

Home Search Miscellany Updates About me Contact Menu
San Antonio Area Freeway System
PROJECT INFO: SH 151 from Loop 410 to Loop 1604

This page last updated December 21, 2024

Traffic

TRAFFIC ADVISORY


The westbound SH 151 ramp to northbound Loop 1604 has permanently closed. A new temporary entrance ramp has opened further down before Culebra and will remain in use until the new connector opens next summer.

The northbound Loop 1604 exit to Culebra Rd. has permanently closed. Traffic headed to Culebra should exit at the SH 151 exit and follow the new access road through the SH 151 interchange to Culebra.


Location
  • SH 151 from Loop 410 to Loop 1604

Status
Timeline
  • Construction started in May 2023 and is expected to be complete in early 2027.

  • This project had been expected to start in 2025, but unexpected funding became available in late 2022 allowing it to be accelerated.


ADVERTISEMENT




On this page:


Project description

This $100 million project will construct multiple improvements in the SH 151 corridor between Loop 410 and Loop 1604.

Widening
This project will widen SH 151 from four to six lanes (i.e. three lanes each way) with a concrete center barrier. The new lanes will be added in the existing grassy median between the eastbound and westbound lanes. This will require the installation of an underground storm drain system.

SH 151 to northbound Loop 1604 connector
This project will also build a new connector from westbound SH 151 to northbound Loop 1604 to replace the existing tight "J" ramp there. The new connector will exit from 151 just past the current exit to northbound 1604. It will be two lanes and will be mostly at ground level except for a "braided" overpass over a new extended northbound access road (more on that below.) After merging with the existing Loop 1604 mainlanes on an expanded overpass over Culebra, there will be four northbound lanes (two lanes from the connector plus the existing two through lanes.) The far right lane will then exit at Shaenfield Rd., and the remaining right lane will end just past the Shaenfield exit. Given that fully one-quarter of northbound traffic passing over Culebra exits at Shaenfield, it is not expected that this will result in much of a bottleneck.

151 to 1604 connector schematic

Location of planned new westbound SH 151 connector to northbound Loop 1604
Click on the image to open a larger annotated version, or view the schematic at the bottom of this page for more details.
(Base image from TxDOT; annotations by Brian Purcell)

Northbound Loop 1604 exit to Culebra
To best accommodate the new connector and provide better overall traffic flow for northbound 1604, the existing northbound Loop 1604 exit to Culebra will be removed. The Culebra exit will be co-located with the current northbound exit to SH 151 near Northwest Vista College. That exit will be widened to two lanes, and the northbound access road will be extended through the SH 151 interchange to reach Culebra, passing under the new connector from 151 to northbound 1604 along the way.

Turnarounds and intersection improvements
Back on 151, new turnarounds will be added at Military Dr., Westover Hills Blvd., and Wiseman Blvd. Several existing right turn lanes at various intersections will be extended and a few new right turn lanes built, and an assortment of other minor intersection improvements will be made.

Miscellaneous
A previously-planned new eastbound exit ramp to Military Dr. inside Loop 410 was dropped from this project, but may be included in a future project.

The existing lighting along SH 151 will be removed and replaced with high-mast lighting.

EXISTING CROSS-SECTION

Existing 151 cross-section
FUTURE CROSS-SECTION

Future 151 cross-section

The number of mainlanes shown is the number of through lanes and does not include auxiliary or transitional lanes. The number of access road lanes varies depending on location. Diagrams are for illustrative purposes only and are not to scale.


How this project will help

This is a pretty basic freeway expansion and improvement project.

The added lanes are needed to provide capacity for current and future traffic volumes in this corridor. Traffic volumes have increased substantially since the opening of the flyover connectors at Loop 410. Computer modeling of the improvements vs. doing nothing shows a decrease in 2045 travel times of 34% to 60% depending on direction and time of day.

The connector from westbound SH 151 to northbound Loop 1604 will alleviate the congestion and safety issues caused by the current "J" ramp there.

The turnarounds and turn lane improvements will help reduce congestion and improve operations at those intersections.


FAQ



Schematic

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 that there have been a few changes in the plans since this schematic was released; these changes are noted in blue call-outs on the schematic.

Schematic thumbnail

Click the image above for a full-sized schematic of this project


Video

I put together a video that gives an overview of this project:





Other sites of interest

TxDOT - SH 151 from Loop 1604 to I‑410
https://www.txdot.gov/inside-txdot/get-involved/about/hearings-meetings/san-antonio/052119.html