changes have been made to this project A
few elements of this project have changed since the preliminary
schematics were released. Those changes have been noted in the
description below and on the schematics at the bottom of this page.
151 from Loop 410 to Loop 1604
Status Under construction (22% complete)
Timeline Construction started in May 2023 and is expected to be
complete in late 2026.
This project had been expected to start in 2025, but unexpected funding
became available in late 2022 allowing it to be
Description This $100 million project will construct multiple
improvements in the SH 151 corridor between Loop 410 and Loop
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
undeground storm drain system.
SH 151 to northbound Loop
This project will also build a new connector from
westbound SH 151 to northbound Loop 1604 to replace the existing
hairpin curve 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 in a
minute.) 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.
Northbound Loop 1604 exit to
To best accommodate the new 151-1604 connector and provide better
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
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.
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.
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.
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
number of mainlanes shown is the number of through lanes and does not
include auxiliary or transitional lanes.
access road lanes varies depending on location.
purposes only and are not to
project will help The added lanes are needed to provide capacity for current
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 hairpin ramp there.
The turnarounds and turn lane improvements will help reduce congestion
and improve operations at those intersections.
problem isn't that there aren't enough lanes on SH 151, it's the
bottleneck at Loop 1604.
That's partially true. First of all, there is indeed a capacity problem
151. For example, traffic backs-up on eastbound SH 151 in the morning.
Since this is headed away from the Loop 1604
interchange, that's obviously not the
cause. Adding the extra lane on 151 will help alleviate that congestion.
On the westbound side, yes, the bottleneck at the exit to Loop 1604
northbound is a major
factor in the recurring congestion there during the afternoon rush
hour. The new connector from
westbound SH 151 to northbound Loop 1604 that's planned as part of this
project should resolve that. Even so, traffic volumes headed
westbound now and in the future warrant another lane being
to the corridor. In
fact, since the flyovers at Loop 410 opened, traffic counts in this
corridor have increased substantially.
Why didn't they build the
westbound SH 151 connector to northbound Loop 1604 when they
built the other
flyover there? There
for that connector at that time. In fact, the flyover that's there now
was not even originally part of the project that built it; it was added
later when additional funding for it became available.
Why was that hairpin ramp from
151 to northbound Loop 1604 built
that way? This
is a bit of an artifact from the original intersection there. That
ramp was actually one leg of the original "T" intersection of westbound
SH 151 and
Loop 1604 when 1604 was just a two lane road and you could
turn left there onto southbound Loop 1604. It was converted
to the "J" ramp that's there today about 20
years ago when Loop 1604 was upgraded to a divided highway in
conjunction with the construction of the overpass at Culebra, after
which traffic could no longer turn left onto Loop 1604. With the new
overpass, an exit for Culebra was needed. The limited space there
dictated where that new exit could be, which in turn restricted where
an entrance to
northbound 1604 from 151 could be in order to provide adequate
merging/weaving space between the two. Given
the low traffic volumes at that time and the limited funding available,
a more elegant solution was not cost-effective, and so the existing
roadway was re-purposed and converted to the tight "J" ramp that's there today
considered to be adequate for the time being.
"braided" entrance ramp going from the access road over the Culebra
exit was briefly
considered a few years back. However, it was determined that it was not
the best long-term solution and that waiting a little longer to be
able to build the direct connector was the best option.
Today's SH 151 to northbound Loop 1604 ramp ca. 2000 showing it in its original configuration as a "T" intersection
SH 151 needs to be at least four
lanes each way. Adding just one lane is a waste of money.
The decision to add one lane in each direction was based
traffic projections. Sure, adding two lanes might 'future-proof" the
corridor more, but it's a significant added cost that could not be
on the projections. Furthermore, the funding to do so is not
available right now. So the options were to expand to the three lanes
and provide some good relief now and for many years, or
indeterminate amount of time for funding to be available
Will the endangered spider delay
Almost certainly not. The spider that caused
the original project to build an underpass for SH 151 under Loop 1604
to be cancelled and re-designed is actually not even on the endangered
anymore. That said, the area is known to be habitat for other
endangered spiders, so TxDOT had to consult with the US Fish
& Wildlife Department to ensure that approved mitigation plans
in place. Since this is a known issue this time around, and this
area has been extensively surveyed in conjunction with this project and
work, no problems are expected.
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;
are noted in blue callouts on the schematic.
put together a video that gives an overview of this project:
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