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Other San Antonio Area Roads
Interstate
35/San Antonio-Austin Corridor |
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This page
last updated January 4, 2020 |

The I-35 San Antonio-Austin Corridor connects
a booming region with an aggregate population of 4.7
million stretching 100 miles from South San Antonio to Georgetown north
of Austin and is the busiest inter-metro Interstate in Texas
with traffic counts exceeding 100,000 vehicles per day. From south to
north, the
corridor traverses Bexar, Guadalupe, Comal,
Hays, Travis, and Williamson counties and the cities of San Antonio,
Live Oak, Selma, Schertz, Cibolo, New Braunfels, San Marcos, Kyle,
Buda,
Austin, Round Rock, Pflugerville, and Georgetown.
This
page gives an overview of the 48
mile core section of the corridor between the San Antonio and
Austin urbanized areas, or more specifically from FM 482 in Schertz to
SH 45 near Buda. To continue south, see the I-35
North page in the San Antonio Area Freeway section
of this site.
Roadway
configuration
Lanes
- 6 lanes from
FM 482 to Solms Rd.
- 8 lanes in New
Braunfels from Solms Rd. to FM 306
- 6 lanes from
FM 306 to SH 45
There
is a
left-lane truck restriction in effect for the entire corridor from just
inside Loop 1604 in Live Oak to north of Georgetown.
Frontage roads
Nearly
continuous frontage roads along the entire route. Originally, the
frontage roads did not continue over
the Guadalupe River in New Braunfels nor over the Blanco River in San
Marcos, and there was a gap in the southbound frontage road
between Kyle Crossing and Kyle Parkway as well as through downtown Kyle
where BR 35 functioned as the frontage road. Frontage roads were added
at all of those locations during expansion projects between 2000 and
2010.
Prior
to 2000, all of the frontage roads between San Antonio and
Austin were two-way with the exception of a 2.3 mile one-way section
through San Marcos. Expansion projects since 2000 have converted nearly
all of the frontage roads in the corridor to one-way. The last section
remaining two-way is between Conrads Rd./Kohlenberg Rd. north of New
Braunfels and FM 1102/York Creek Rd. near the Comal/Hays county line.
Work to convert that section to one-way is scheduled to begin in 2020.
Completion of that project will result in all of the I-35 access roads
between the Medina River south of San Antonio to Hillsboro being
one-way.
Traffic management
In
2008, TxDOT
installed Intelligent Traffic System (ITS) equipment throughout the
corridor consisting of cameras, speed detectors, and dynamic message
signs. This system connects to the TransGuide ITS system in San
Antonio and the CTECC ITS system in Austin, thus providing real-time
corridor traffic information to motorists in both cities.
Traffic
Interstate
35 is the main freeway tying the San Antonio/Austin region together
and, as a consequence, is frequently overloaded on many
sections. All
counts in the corridor now exceed 100,000 vehicles per day.
In
addition to
local growth, NAFTA has put an additional strain on the corridor as
I-35 connects the nation's busiest freight border crossings in
Laredo to the Midwest and results in a high level of truck traffic in
this corridor. Consequently, officials lobbied to have it designated as
a NAFTA
Superhighway to secure federal funding for various conventional and ITS
improvements and the entire corridor has been upgraded to a six and
eight lane facility in the past two decades.
Speed
limits
- 70
mph along
entire corridor
Future
plans
Construction
of various frontage road, ramp, intersection, and overpass improvements
north of New Braunfels is set to start in 2020 (more details here) and
a similar project at Posey Lane is currently underway. Additional
operational improvement projects at several locations are in various
stages of planning.
A
statewide planning study for I-35 in 2016 recommended several expansion
projects in the corridor. However, there are currently no advanced
plans underway for any such expansions in the foreseeable
future.
Planning
for a commuter rail line between San Antonio and Austin was suspended
in 2016 after Union Pacific would not agree to the use of its rail line
and the cost of building a new rail line and its proposed location were
determined to be not feasible.
The
I-35 corridor has been mentioned as a possible location for a future
"hyperloop" transportation system.
SH
130
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In an effort to alleviate the growing traffic
problems in the I-35 corridor, a parallel
tollway, SH 130, was built. For more information, see the the SH 130 page. |
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