|| Other San
Antonio Area Roads
35/San Antonio-Austin Corridor
last updated July 14, 2023
The I-35 San Antonio-Austin Corridor connects
a booming region with an aggregate population of about 5
million people stretching 100 miles from South San Antonio to
Georgetown and is the
busiest inter-metro Interstate in Texas,
with traffic counts exceeding 100,000 vehicles per day. From south to
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,
Austin, Round Rock, Pflugerville, and Georgetown.
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.
- 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
left-lane truck restriction in effect for the entire corridor from just
inside Loop 1604 in Live Oak to north of Georgetown.
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
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 all of the frontage roads in the corridor to
one-way. The last section
remaining two-way was 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 was completed in 2023, the
result of which is that all of the I-35 frontage roads
between the Medina River south of San Antonio to Hillsboro are now
The speed limit is 70 mph along the entire stretch from Loop 1604 to SH
installed Intelligent Traffic System (ITS) equipment throughout the
corridor consisting of cameras, speed detectors, and dynamic message
signs. This system connects to the TransGuide center in San
Antonio and the CTECC center in Austin, thus providing real-time
corridor traffic information to motorists in both cities.
35 is the primary freeway tying the San Antonio-Austin region together
and, as a consequence, is frequently overloaded on many
counts in the corridor now exceed 100,000 vehicles per day.
local population and industrial growth, international trade has put an
additional strain on the corridor as
I-35 connects the nation's busiest freight border crossings in
Laredo to the Midwest, resulting in a high level of truck traffic in
this corridor. Consequently, officials lobbied to have it designated as
Superhighway" to secure federal funding for various conventional and
improvements, and the entire corridor has been upgraded to a six and
eight lane facility in the past two decades.
of various frontage road, ramp, intersection, and overpass improvements
north of New Braunfels is set to be complete in 2023, and additional
operational improvement projects at several locations in and south of
New Braunfels are in various
stages of planning or construction. More details on those projects here.
statewide planning study for I-35 in 2016 recommended several expansion
projects in the corridor. However, no funding has been identified for those projects, and there is currently no advanced
planning underway for any such expansions.
for a commuter rail line known as "Lone Star Rail" 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, along with practical
challenges in locating such a line, caused the sponsoring agencies to
withdraw. However, there has been some talk recently about resurrecting
the idea. In the meantime, a pilot project for a public inter-urban bus
line is in the works. The proposed route would run from downtown Austin
to the Randolph Park & Ride at the intersection of I-35 and Loop
410 in northeast San Antonio.
I-35 corridor has been mentioned as a possible location for a "hyperloop" transportation system.
||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.