Antonio Area Freeway System
I-10 from La Cantera to Ralph Fair
page last updated April 24, 2021
from La Cantera Pkwy. to
Ralph Fair Rd.
(For information on the various projects north of Ralph Fair Rd., see
the I-10 West Projects page.)
This $70 million project added one general-purpose
(for a total of three) and one
high-occupancy vehicle (HOV) lane in each direction. These
lanes were generally added in the previously-open center
cross-section below.) No entrance or exit ramp locations
as a result of this project, and no frontage road work was being done--
that was all completed in an earlier project.
new lanes are all toll-free. An earlier plan for this project proposed
adding two tolled managed lanes in each direction, but recent funding
changes allowed the toll component to be removed.
westbound HOV lane starts
just north of La Cantera Pkwy. There is an intermediate
entrance/exit point between Camp Bullis Rd. and Dominion Dr. for
traffic to exit for Boerne Stage Rd. and Ralph Fair Rd. The
lane then continues and ends just north of Boerne Stage Rd.
where it merges into the left general-purpose mainlane.
mainlane then ends just past the Old Fredericksburg Rd. exit.
future project will extend the third general purpose lane and HOV lane
all the way to Boerne.
the eastbound side, a third general-purpose mainlane is added
to the right from the entrance ramp located just north of
Ralph Fair Rd. The HOV lane then starts on the left side
under Ralph Fair Rd. There is an intermediate
entrance/exit point between Stonewall Pkwy. and Camp Bullis Rd. for
traffic wanting to exit to Camp Bullis Rd. and La Cantera Pkwy.
The HOV lane then continues and ends just south of Camp
Rd. where merges into the left
general-purpose mainlane. Planning is underway to eventually extend the
HOV lane south from there.
this project will help
access road lanes varies depending on location.
purposes only and are not to
This section of I-10 is growing rapidly and experiences
congestion. The additional lanes provide additional
capacity. The HOV lanes are the first in an envisioned
of HOV lanes in San Antonio and are intended to help reduce congestion
by encouraging carpooling and mass transit usage.
For more information about local HOV lanes, see the HOV
This project started in September 2017 and was completed in
the first quarter of 2021. The new eastbound lanes opened September
26th, 2020 followed by the
new westbound lanes that opened the weekend of October 17th, 2020.
Also see the HOV FAQ on
the HOV lanes page.
HOV merges will cause bottlenecks.
HOV merges themselves are not expected to create too much of an issue.
Westbound, the three general-purpose lanes will also taper down to two
at Ralph Fair Rd., but the merging of the third general purpose lane
the HOV lane have been staggered to help ameliorate any issues. That
said, the previous congestion in the Dominion area before this project
helped to meter traffic coming into the Leon Springs area, so with that
removed, the area around Ralph Fair Rd. may see some congestion as it
now the new bottleneck. This would have happened even without the HOV
the eastbound side, the previously-existing
entrances from Camp Bullis and from La Cantera and all the jostling
that takes place along that stretch for folks wanting to get off onto
Loop 1604 will be more of an issue than the HOV lane merge. As with the
westbound side, the eastbound congestion up by Dominion and Leon
Springs prior to this project helped to meter traffic coming into this
area, and the addition of the third lane at La Cantera opened up some
"just in time" capacity to help ease things on the 1604 approach. With
the completion of this project, that upstream kink is now gone,
so some additional congestion on that approach to 1604 is now
likely. It will seem to be a result of the HOV merge since that's
what's new in that vicinity, but it will really be more a result of the
existing ramps. Again, this would have happened even without the HOV
lane. Fortunately, that will all be cleaned-up
with the Loop 1604 interchange project that is set to start
construction in early
wasn't this expansion done when the
access roads were rebuilt a few years ago?
See the answer for the "Why
is there constant construction...?" question near the top
of the I-10
West Projects page.
wasn't this expansion done when the
Camp Bullis and Dominion overpasses were built?
that time, TxDOT had not completed the required planning
and environmental studies for a mainlane expansion and there was no
funding for such a project. The Camp Bullis overpass was
rebuilt to provide space beneath it for urgently-needed turnarounds and
improvements necessitated by nearby development (mainly The Rim.) The
overpasses had to be lengthened and raised, which required raising the
approaches on I-10. The area between Camp Bullis Blvd. and Dominion Dr.
was in a floodplain, so since they were raising the roadway for the
Camp Bullis overpass, they needed to address the drainage issues there,
which required rebuilding the roadway. However, planners designed that
section to easily facilitate the future expansion of the mainlanes.
overpass was built to facilitate convenient circulation and emergency
access in conjunction with converting the access roads to one-way,
which itself was necessitated by traffic growth in the area. (See next
bullet for more details.)
Waiting to complete those overpass projects until the mainlane
expansion project development was completed and funded would have
delayed the much-needed improvements they provided by nearly a decade.
things in life, highway improvements often are incremental due to
overpass at Dominion Dr. was only built to give the residents
of The Dominion easy
access to inbound I-10.
doesn't really have anything to do with this project, but this seemed
like a good place to answer this persistent but false allegation among
some frankly cynical
people in this area. An overpass was needed between
Camp Bullis Rd. and Boerne Stage Rd. to provide a convenient
crossover for residents on both
sides of I-10 in order to convert the
access roads to one-way. Without an overpass in this area, traffic
needing to go the opposite direction on I-10 would have to travel up to
miles out of the way to do so. This location was selected because it's
nearly halfway between Camp Bullis Rd. and Boerne Stage Rd.,
because it was at a location that connected a roadway on the east side
of I-10 with an already-planned arterial (Stonewall Parkway) on the
west side (this arterial had been on the City of San Antonio's major
thoroughfare plan for many years prior), and because it was the best
location to facilitate emergency vehicle access to locations
on the east side of I-10 from the fire station
located on the west side
of I-10 just north of there. The fact that it provided improved access
to I-10 from The Dominion was certainly a beneficial consequence for
them, but it was not the determining factor for the need and location
for that overpass.
Below is an annotated detailed project schematic
and a rendering of what the finished roadway will look like.
the image below to see a detailed annotated schematic of this project
future I-10 looking inbound north of Dominion Dr
sites of interest