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INFO: Bandera Rd. Superstreet (Helotes)
page last updated July 8, 2020
Bandera Rd. (SH 16) from Loop 1604 to Diamond K Trail
Advanced design. See timeline below.
This project will convert Bandera Rd. to a
superstreet from just outside Loop 1604 to just south of FM
by converting the intersections at Hausman/Leslie and Cedar Trail to
restricted-crossing intersections, adding signalized turnarounds at
multiple intermediate locations, and
closing the crossover at Diamond K Trail. This project will also
construct a new signalized left turn from northbound Bandera Rd. to
Legend Trail and will expand the southbound Bandera left turn to
Hausman to two lanes.
restricted-crossing intersections will prevent traffic
on Leslie/Hausman and Cedar Trail from going straight or
turning left. Instead, all traffic will make a right turn, then use
a signalized turnaround about 1000 feet downstream to
make a U-turn and continue in the intended direction of travel. Left
turns from Bandera Rd. to those cross streets will still be allowed. To
better visualize this, click on
the "turning movements diagram" below.
project will also build an underground storm drainage system and will
include sidewalks throughout.
intersection at FM 1560 South was converted to a superstreet
configuration in 2018, and the intersection at Loop 1604 was converted
to a displaced left turn (DLT) in 2019, so this will close the gap
between these two improved intersections and complete the master plan
for this section of Bandera Rd. TxDOT plans to eventually continue the
superstreet configuration all the way to Triana Pkwy.
superstreet is also known by the more technical nomenclature of
"restricted crosssing U-turn" (RCUT) intersection.
TURNING MOVEMENTS DIAGRAM
Click above to see a
simplified diagram of the turning movements at each
this project will help
Hausman/Leslie intersection experiences
significant to severe recurring congestion during both the morning and
evening rush hours. By eliminating the through-traffic and left-turns
on Leslie/Hausman and Cedar Trail, the green time required for those
movements can instead be combined with the left turn green time for
traffic turning from Bandera onto those streets. That essentially
eliminates the green time needed to service the cross streets, meaning
more green time can be allocated to the remaining movements,
which therefore moves more traffic through the intersection in the same
period of time. This configuration is expected to provide good
long-term congestion mitigation
based on 20-year traffic projections.
further explanation on how a superstreet functions and how it improves
traffic flow, see the main superstreets
it's currently not as congested, converting the Cedar Trail
intersection is necessary to provide continuity of improvement. If the
Cedar Trail intersection were not also converted, then it would soon
become a bottleneck due to the improved throughput on either side of it.
new left turn at Legend Trail will provide better access to the Stanton
Run neighborhood from northbound Bandera Rd. That traffic today must
make a U-turn at Cedar Trail and a U-turn at that location will not be
possible after the
conversion. Since a turnaround for southbound Bandera Rd. was necessary
at that location anyway, the left turn to Legend
Trail was a sensible addition.
the crossover at Diamond K Trail is necessary as it has become a
dangerous crossover location and will be more so in the future, and
direct crossovers like this within a superstreet
segment negate the improvements afforded by the superstreet.
Construction is expected to begin in early 2022 and
take about two years to complete. The construction of an underground
drainage system added to the duration of this project.
- This looks confusing.
It will cause lots of crashes.
of the first knee-jerk assertions made when an unconventional
intersection is introduced. With any change-- even more conventional
as new signals or lanes-- it naturally takes
drivers a little time to adapt. With a superstreet, because all traffic
on the intersecting
is forced to turn right, most confusion is quickly overcome
instinctively once the driver has turned or as the driver follows
other more experienced drivers through the intersection. Additionally,
because all traffic is flowing in the same direction and
is protected by signals, the likelihood of collisions is substantially
reduced, even during the adjustment period. Superstreets also
improve safety by reducing conflict points (the
point where vehicle paths cross) by half.
superstreets show improved safety. A study for
North Carolina DOT showed that superstreets reduced traffic collisions
by 46% and decreased crashes with injuries by 63%. A study of
superstreet intersections in Missouri showed a 54% reduction in
injury and fatal crashes. Many people predicted mayhem at the
Bandera/1604 displaced left-turn intersection, but crashes decreased
44% during the first nine months after it was completed.
- How does this crazy design
traffic? How does adding even more traffic signals help?
This intersection design improves traffic because, by forcing all
traffic on the cross street to turn right, the green time for that can
be overlapped with the green time for traffic turning left from Bandera
onto the cross street. This essentially eliminates the green
that would needed for the through
left turn movements on the cross street, so that time can then
the remaining movements, thus moving more traffic through the
intersection in the same
amount of time. Although there are extra signals, they are all much
more efficient and are better coordinated. See the "How a superstreet works"
section of the main superstreets page
for a deeper explanation of the superstreet "secret sauce".
- All they have to do is adjust the
signal timing and that will solve the problem.
a common belief that congestion can be solved by simply
adjusting the signal timing. In some specific cases, that can be true,
but at a very busy intersection like this where there has to be
sufficient green time for eight different movements on every cycle, the
signals can only be optimized so much before the laws of physics win.
For example, the green time on Hausman could be extended to help clear
out the peak period backups that occur there, but that means the light
will stay red longer for Bandera, which then increases the congestion
there. If the green time on Bandera is then increased to ease those backups,
that means the light will stay red longer for Hausman and you're right
back where you started. So as you can see, it's really not as easy as
- This causes people to have to go
out of their way, which is inconvenient and will require more time to
get across Bandera Rd.
folks understandably are bothered that to
or go straight on the cross street requires going out of one's way to
accomplish. This is true and will always be perceived as an
inconvenience by many drivers, but because wait times will be shorter
overall congestion in
area reduced, travel time through the intersection should typically be
shorter than it would be at a conventional intersection
even with the added time necessary to use the turnaround. Also
in mind that there are many other examples where traffic
wanting to make a left turn is prohibited from doing so due to a
median, freeway, or one-way street and must therefore turn right
first, then make a downstream U-turn or series of left turns,
so this situation is not unprecedented or unique to superstreets. In
fact, this has already been the case along much of this section of
Bandera Rd. due to the existing median.
I'm headed south on FM 1560 (Hausman Rd.) and want to go to Wal-Mart,
Starbucks, Bill Miller's, or O'Connor High School, or head
southbound on Bandera Rd., how do I get
At Bandera Rd., you'll turn right, travel about 1000
feet to a turnaround (just past Little Caesar's Pizza), then head
southbound on Bandera where you can turn right at Bill Miller's,
Leslie Rd. (for O'Connor HS), Starbucks, or Wal-Mart,
or continue straight on southbound
Bandera. To return to Hausman Rd. from Bill Miller's, O'Connor,
Wal-Mart, you'll turn right onto Bandera Rd. and use a turnaround just
past Wal-Mart to return to Hausman Rd.
- Why not build overpasses instead?
Across the country, traffic engineers have
discovered that innovative
intersections like this can produce good congestion relief and safety
at a fraction of the cost and construction time of flyovers and other
grade-separated solutions. This allows the limited
be saved and used for other needed projects.
and future traffic volumes and safety considerations along Bandera Rd.
aren't sufficient to justify the construction of overpasses or
conversion to a freeway, but they are in the "sweet spot" to support a
superstreet. Furthermore, the right-of-way along Bandera Rd. is not
wide enough for overpasses or a freeway, so the cost would be
considerably higher as additional right-of-way would have to be
obtained, which likely would result in the displacement of many
- Why are there signals to leave
This is to
prevent slower moving vehicles from entering the faster traffic stream
and causing conflicts that could result in collisions or
- Will the Circle A Trail
intersection be changed to allow left turns again?
No, that intersection is outside the scope of this project.
- Are there any other
superstreets in San
there have been two superstreet segments in San Antonio. One is on US
281 north of Loop 1604 and the other was nearby on Loop 1604 between
Braun Rd. and Culebra Rd. Both were built as short-term solutions while
funding for freeway expansions was obtained. The Loop 1604 superstreet
was replaced by a freeway in 2016, and the US 281 superstreet will be
replaced by a freeway in the next year or so. Unlike the 281 and 1604
superstreets, the superstreet in Helotes is considered a long-term
solution. A superstreet was also
considered for Bandera Rd. inside Loop 1604, but has been tabled while
a new corridor study
- Who came up with this cockamamie
design? This won't work and is just a waste of money.
superstreet design has been used in several US states for the past
couple of decades and has a proven
track record of improving traffic wherever it has been implemented.
Both the US 281 and Loop 1604 superstreets showed appreciable
improvments, and computer modeling shows that this superstreet will do
the same. A superstreet
is one of several types of "innovative" or "alternative" intersection
being implemented across the country at intersections
where improvements from conventional expansions will be short-lived but
where conditions do
not warrant more expensive traditional upgrades such as
flyovers. Many people expressed similar doubts about the nearby
Bandera/1604 DLT intersection, but the new design has substantially
reduced congestion and crashes there.
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.
DETAILED PROJECT SCHEMATIC
Click above to see the detailed
annotated schematic for
sites of interest