Portions
of this
project are currently in design The
descriptions below are based on preliminary schematics and,
as a result, details may change before the project goes to construction.
The first two phases of this project are being built using a
design-build
contract, so final
plans are not available before construction starts as they
typically are with a conventional bid contract. However, based on
TxDOT's
specifications and approved schematics for the project, the ultimate
design isn't expected to
differ substantially from what is described below.
TxDOT
has been studying an expansion of I-35 from downtown San Antonio to the
Schertz area since the mid '90s. For much of the past decade,
those plans necessarily included tolled lanes due to the project's cost
and funding constraints. But with the deprecation
of tolling statewide in the past few years and resultant increased tax
funding for
highways, the toll component of this
expansion has been removed, and TxDOT is
now planning to expand I-35 by adding
non-tolled express lanes and HOV lanes from AT&T
Center Pkwy. to FM 1103. The new lanes will be elevated
(double-decked) south of FM 3009 and be at-grade
from there
to FM 1103.
Below
is complete information and the latest status of this project.
In 1996, a Major
Investment Study of the I-35 northeast corridor recommended
barrier-separated express lanes as the best long-term solution for the
corridor.
However, acute funding shortages in the early 2000s caused this plan to
be shelved.
In
2009, the Alamo Area Regional Mobility Authority (ARMA)
included this corridor as a secondary phase for a local tollway
system
and initiated a Planning and Environmental Linkages (PEL) study in
2011,
which essentially reiterated the findings of the 1996 study. The
subsequent in-depth study proposed two express lanes in each direction
with connectors
to Loop 1604, Loop 410 Northeast, and Loop 410 South. As the
plans were further fleshed-out, it was determined that the new
lanes would have to be elevated along most of the route from downtown
to the FM 3009 area due to right-of-way constraints. The
environmental study for that project was
completed and approved in 2015.
Around
that time, tolling became deprecated both locally and statewide as the
legislature and citizens approved new funding sources for highways. As
a result, the various local planned toll projects were successively
"de-tolled" as new funding sources were identified for them. Tolls were
removed from the I-35
project in June 2018.
With
the toll
component removed, TxDOT began work redesigning the project without
tolls.
Additionally, recent local transportation policy changes have promoted
the addition of HOV lanes to freeway expansion projects where feasible.
Given the length and commuting patterns of
this corridor, as well as an already impressive 10% carpooling rate,
HOV lanes were determined to be a good fit and so were added to the
project.
Rendering
showing planned double-decking with cutaway view
Project description
This nearly $3 billion project will
add non-tolled express
lanes and HOV lanes on about 16 miles of I-35 from AT&T
Center Pkwy. to FM 1103. The new lanes will be elevated
(double-decked) south of FM 3009 and be at-grade
from there
to FM 1103. There will be two express lanes in each direction from
AT&T Center Pkwy. to Rittiman Rd., two express lanes plus an
HOV lane in each direction from Rittiman Rd. to the Bexar county
line, one
express lane and one HOV lane in each direction from Schertz Pkwy to FM
3009, and one new general-purpose at-grade mainlane and one HOV lane in
each
direction from FM 3009 to FM 1103.
The
project will also build new interchanges
above or near the existing
interchanges to connect the new upper level lanes to Loop 410 South,
Loop
410 Northeast, Loop 1604, and Pat Booker Rd., as well as an
intermediate
access point to and from the I-35 mainlanes at the Bexar county line,
and make some incidental changes to existing
roadways to accommodate the
new elevated lanes and interchange ramps. The new interchanges will
serve the upper levels
only; the existing interchanges at those locations
will remain as they are and will continue to serve the lower-level
lanes of I-35.
Cross-section from AT&T
Center Pkwy. to Rittiman Rd.
Cross-section from Rittiman Rd.
to Bexar county line
Cross section from Bexar county
line to FM 3009
Cross section from FM 3009 to FM
1103
NOTE
Number of access road lanes varies depending on location.
Diagrams are for illustrative purposes only and are not to scale.
Unlike
the double-decked freeways downtown, the upper levels on this project
will be express lanes,
meaning there will be limited entrances and exits along their
length. The
intent for the new lanes is to
provide an express facility for longer-distance through traffic in the
corridor, but this will also benefit the lower
level by removing much of that long distance traffic from those lanes.
In
addition to the north end (FM 3009 area) and south end (AT&T
Center Pkwy. area), motorists will also be
able
to enter or leave the elevated lanes at the following locations:
Bexar
county line:
Southbound
entrance from I-35 mainlanes to elevated lanes
Northbound
exit from elevated lanes to I-35 mainlanes
Loop
1604
Connectors to/from
Loop 1604 (initially only to/from west of I-35)
Pat
Booker Rd.:
Entrance
from Pat Booker to southbound elevated lanes
Exit from
northbound elevated lanes to Pat Booker
The access ramps
will be located on Pat Booker between I-35 and Loop 1604
Loop
410 Northeast:
Connectors to/from northbound and
southbound elevated lanes, connecting to Loop 410 near Perrin-Beitel Rd.
Loop
410 South:
Connector from northbound Loop 410 to
northbound elevated lanes north of FM 78
Connector
from southbound elevated lanes to Loop 410 southbound north of FM 78
Southbound
exit from elevated lanes to I-35 southbound access road south of
Rittiman Rd. (i.e. BAMC exit)
Crossovers
between the two upper levels will be provided for
emergency access
at three locations in the corridor: between Eisenhauer Rd. and
Walzem Rd., near O'Connor Rd., and near Olympia Pkwy. (see rendering
below.)
The
project will also include several ramp
revisions and other minor adjustments to existing roadways
to accommodate the
access and egress locations and columns for the new elevated lanes. Turnarounds
will be added at Schertz Pkwy., Cibolo Valley Dr., and at FM 2252, and
new overpasses and intersection improvements will be also included
at Cibolo Valley Dr. and FM 2252.
Rendering
of proposed emergency crossover near O'Connor Rd.
Timeline
Current
funding constraints, as well as engineering and contracting
considerations, require the project to be divided
into
multiple
phases. Initially, funding was only available for the central segment
from Loop 410
Northeast to FM 3009, including the new connectors to Loop 410
Northeast and
to Loop 1604 to the west of I-35. In August 2019, the Texas
Transportation Commission approved additional funding for the southern
segment from Loop 410 South to Loop 410 Northeast. The
remaining segments-- from
FM 3009 to FM 1103, Walter St. to Loop 410 South, and the connectors
for Pat Booker Rd.
and for
Loop 1604 east of I-35-- are currently unfunded.
Phases 1 and 2a of this
project are being built using a design-build
contract, which means that
TxDOT has/will select a contractor who will complete the final design
of
the project, build it, and then maintain it for five years. This
process generally results in time
and cost savings due to the ability to overlap design and construction
timelines as well as increased efficiencies from a single entity
managing the entire project. The remaining phases are currently planned
to use the more traditional design-bid-build process.
PHASE 1 (Central segment):
Loop
410 Northeast to Bexar county line
Status: Construction started in June 2022, 27%
complete
Timeline: Estimated
completion
in late 2027
Cost:
About $1.62 billion
This phase will
include the following:
Two
elevated express lanes and one HOV lane in each direction
Elevated
connectors to Loop 410 Northeast just south of the existing interchange
except southbound I-35 to westbound Loop 410 connector, which will
mirror the existing connector
Elevated
connectors to Loop 1604 west of I-35
Upper levels for this phase will end at the north at the
intermediate access point at the Bexar county line and at south at the
Loop 410 Northeast interchange
Emergency
crossovers for the elevated lanes near O'Connor Rd. and Olympia Pkwy.
Additional
lanes on Loop 410 Northeast to provide access to and from the new
elevated lanes
Ramp
revisions on eastbound Loop 410 from Nacogdoches to Perrin-Beitel to
accommodate the new interchange ramp and smooth traffic flow
approaching
it
Ramp revisions and frontage road alignment adjustments at a
few locations to accommodate elevated lane columns and ramps
This
phase will require the construction of more than 800 bridge spans
consisting of 4,500 concrete beams, 900+ columns, and six million
square feet of
bridge decks
PHASE 2a (South segment): Loop 410 South to Loop 410 Northeast
Status: Funded
Timeline:
Currently expected to start construction in late 2023 with estimated
completion in 2028
Cost:
About $654 million
This phase will
include the following:
Two
elevated express lanes in each direction from Petroleum Dr. to
Rittiman Rd. (This section will be "ghost" bridges when completed; i.e.
they will not be used by traffic as they will dead-end in the air until
they are extended to the south in a later phase.)
Two
elevated express lanes and one HOV lane in each direction from Rittiman
Rd. to Loop 410 Northeast
Elevated
connectors to and from Loop 410 South at the same location as today's
Loop 410 South Cutoff interchange, dropping down to Loop 410 between
I-35 and FM 78
Southbound elevated lanes exit to I-35 access road
north of George Beach
Ave.
Ramp
revisions on southbound I-35 between Rittiman Rd. and George Beach Ave.
Emergency
crossover for the elevated lanes between Eisenhauer Rd. and Walzem Rd.
PHASE 2b (South segment):
Walters St. to Loop 410 South
Status: Unfunded
Timeline:
Tentatively planned for 2025
Cost:
About $250 million
This phase is currently planned to be broken into two
projects for construction:
Walters St. to Loop 410 South
Loop 410 from I-35 to WW White Rd.
This phase will
include the following:
Two
elevated express lanes in each direction from AT&T
Center Pkwy. to Petroleum Dr. where they will connect with the section
previously built in Phase 2a
Widening
of I-35 and ramp revisions between Walters St. and AT&T Center
Pkwy. to accomodate approach to and merge from elevated lanes
Reconstruction and widening of Loop 410 bridges over FM 78,
construction of a southbound Loop 410 access road over FM 78, and ramp
relocations
PHASE 3 (North segment): Bexar
county
line to north of FM 1103.; Pat Booker Rd./Loop 1604 East interchange
Status: Unfunded
Timeline: Tentatively
planned for 2027
Cost:
About $417 million
This phase will
include the following:
One elevated express lane and one HOV lane in each
direction from Bexar county line to FM 3009
One additional mainlane and one HOV lane in each direction
from FM 3009 to FM 1103
Widened overpasses at Cibolo Valley Dr. and at FM 2252
Ramp revisions between FM 3009 and FM 1103
New turnarounds at Schertz Pkwy., Cibolo Valley Dr., and FM
2252
Elevated
connectors to Loop 1604 east of I-35
Elevated connectors to Pat Booker Rd.
Changes to Pat Booker Rd. between Loop 1604 and I-35 to
accommodate new ramps
First
column for elevated lanes under construction near I-35 and Shin Oak (Source: I-35 NEX Twitter
feed)
How this project will help
This corridor experiences frequently-recurring congestion due to
traffic volumes regularly exceeding the capacity of the road.
Studies of
the corridor in the 1990s and early 2010s determined that a significant
percentage of the traffic is passing all the way through the corridor
or traveling between the major interchanges, and therefore
recommended barrier-separated express to segregate
that traffic-- including a substantial amount of truck traffic-- from
the local
traffic that will remain in the
existing mainlanes, thus reducing congestion
there.
It is estimated that when the first
phase is complete, travel time on the existing mainlanes between the
Bexar county line and Loop 410 North will be cut in half from about 20
minutes to less than 10 minutes. When the entire project is complete,
the travel time between FM 1103 and AT&T Center Pkwy. is
estimated to be reduced from about 45 minutes to less than 20 minutes.
HOV
lanes are now being added to major freeway expansion projects where
feasible. The intent is to encourage carpooling and use of mass
transit. Each person that opts to do so is one less vehicle on the
freeway, which helps to reduce congestion and pollution for everyone. A
study of this corridor showed an impressive 10% of commuters
were already carpooling, a number that could increase with the
provision of an HOV lane. For more
information about local HOV lanes, see the HOV lanes page.
Rendering
of proposed northbound double-decking near George Beach Dr.
Schematics
and renderings
Click on one of the areas on the map below to open the
detailed schematics for that section of the project. The base
schematics are from TxDOT with my own annotations added to
help clarify
and
explain the various elements. Each schematic will
open in a new window that you can scroll and zoom.
The
base schematic is the one presented to the public in August 2019. Some
changes have been made since then and they've been patched over the
base schematic; you may notice some slight misalignments and color
differences in those locations
On
the schematic, any elevated segments colored in blue are Phase
1 (called the "base" sections in the legend.) The sections colored in
green south of Loop 410 NE (schematics C and D) are Phase 2.
The sections colored in green north of the Bexar county
line and
east of I-35 at Loop 1604/Pat Booker Rd. (schematics A and B) are Phase
3. (See phase details
above.) Other improvements shown in different colors will
typically
be done in the corresponding phase of the adjacent elevated
section.
Below
are several renderings of what the finished project might look like.
Note that since this project is still in design, these are conceptual
and the exact final project may vary from these. Renderings are
framegrabs from TxDOT's I-35
Expansion Video. and I-35 Northeast Expansion (NEX)
Central Project video.
Typical
proposed double-deck section
Proposed
I-35/Loop 1604 interchange This
view is looking to the west. The Forum is just off the bottom right,
and IKEA now occupies the empty lot at the top left. Note that the new
flyovers connect to the new upper levels of I-35; the existing
cloverleaf will continue to serve the existing lower-level roadways. A
change to the plans since this image was rendered is that the
northbound I-35 elevated lanes exit to westbound Loop 1604 will not be
a left exit as depicted here, but instead will be a righthand exit that
will then go over the elevated lanes. This is shown in the next
rendering below.
Proposed
I-35/Loop 1604 interchange This is
an updated rendering and is looking to the east-northeast. The Forum is
across the interchange
and IKEA is below and slightly behind us.
Upper
level interchange at Loop 410 NE This
view is looking to the northwest. Loop 410 runs left-to-right across
the top. The large building just above the center of the image is
Cowboys dance hall. The elevated ramps at the top left will tie into
Loop 410 at Perrin-Beitel Rd. The existing interchange will remain
as-is. A
change to the plans since this image was rendered is that the
southbound I-35 elevated lanes exit to westbound Loop 410 will not be
in the location depicted here; instead, it has been moved further north
and will mirror the existing southbound I-35 exit to westbound Loop 410.
Another
view of the new upper level interchange at Loop 410 NE This
view is looking north.
Loop 410
South Cutoff interchange This
view is looking south. A
change to the plans since this image was rendered is that the
southbound I-35 elevated lanes exit to southbound Loop 410 will cross
over to the right side of Loop 410 before decending instead of merging
on the left side as depicted in this image.
Video
I
put together a video overview of the NEX project including a
virtual flyover of Phase 1:
I-35 NEX Preview
FAQ For
questions about the HOV lanes, see the FAQ on the HOV
lanes page.
Will
this project be tolled? No. Although earlier versions of this project proposed
adding managed toll lanes,
funding was secured to remove the toll component. Instead, non-tolled
express lanes and HOV lanes will be added.
Why
are they building expensive elevated lanes instead of a more
conventional at-grade widening?
The existing right-of-way along most of the corridor is inadequate for
a
traditional widening, and because of the extensive development along
the frontage roads, the cost to acquire the needed right-of-way would
be more expensive-- and disruptive to the businesses and neighborhoods
along the corridor-- than building the elevated lanes.
Why
aren't there more entrances and exits from the elevated lanes?
A study of the corridor in the 1990s determined that a
significant percentage of the traffic is passing all the way through
the corridor or traveling between the major interchanges, a
pattern that hasn't changed much today. Therefore, the
intent of the new elevated lanes is to
provide an express corridor for that traffic-- including a lot of truck
traffic-- thus removing it from the
existing mainlanes below. Since that traffic is traveling
longer distances, they don't need those intermediate entrances and
exits. Furthermore, additional entrance and exits would increase the
traffic
volumes on those elevated lanes and would also cause additional
"friction" from entering/exiting traffic, both of which would engender
congestion.
Also, providing those additional entrances and exits would
require
additional right-of-way, which is limited in this corridor. This same
concept is used on the I-35 elevated lanes in Austin, the Katy Freeway
express lanes in Houston, the Dan Ryan express lanes in Chicago,
and the New Jersey Turnpike express lanes, among others.
The
lack of entrances and exits will hinder emergency response and will
trap traffic on the upper level if a crash blocks all the
lanes.
To
improve access for emergency vehicles and provide an escape
route for
trapped traffic, emergency crossovers will be constructed at three
strategic locations in the corridor: between Eisenhauer Rd. and Walzem
Rd., near
O'Connor Rd., and near Olympia Pkwy. This same approach has been used
on other long dual-span roads that have limited or no access, most
notably in Louisiana on I-10
over the Atchafalaya Swamp and on the two bridges over Lake
Pontchartrain.
I
will not use/can't access the elevated lanes, so how will
it benefit me?
Traffic that uses the elevated lanes will not be on the mainlanes
below, so this will reduce traffic volumes and associated congestion
there. It is estimated that when
the first phase is complete, peak period travel time on the existing
mainlanes
between the Bexar county line and Loop 410 North will be cut in half
from about 20 minutes to less than 10 minutes.
NOTICE
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
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