(dramatic music)
(traffic swooshing)
- [Narrator] Managing noise from load roadways
can be very challenging especially when elevated structures
are part of the equation.
Less noise improves the quality of life
for residents and outdoors enthusiasts.
Thanks to some innovative designs
which included a unique lightweight acrylic wall.
Noise was vastly reduced here on I-30,
on the west side of downtown Dallas.
- We're looking at the acrylic barrier
because of the lightweight properties,
it's durability,
it's noise reduction,
and it's transparency.
As a test that we could look at all these elements and see.
Would this work in practice,
because TxDOT had never used any material
like this before.
- [Narrator] Experts applied the work they did here
to another loud roadway, the President George Bush Turnpike.
- TxDOT saw the huge success at I-30
and they were facing similar problems with noise at 190.
Of course, the conditions there are different.
It is not an elevated structure.
But the pavement is continuously reinforced
concrete pavement as well.
And based upon the success of the I-30,
they thought about creating a similar project.
- [Narrator] Although TxDOT does not typically
perform noise abatement on existing roadways.
Which is considered a type two noise project.
A study was conducted under this pilot research project.
Life cycle costs and performance of lightweight
noise barrier materials along bridge structures.
The pilot project showed that an acrylic noise
barrier design was effective on existing structures.
- On 2012 NTTA built these noise walls which are eight foot.
The initial modeling had the noise at 80 decibel.
- [Manuel] We had to come up with a design
for something to put on top
of those existing concrete walls.
And we came up with the acrylic barrier design.
- [Daniel] So it's actually helped reduced the traffic noise
for the neighboring properties.
- [Manuel] We measured the effectiveness of the wall
by a test called insertion loss.
In which you put a noise meter
behind the wall and a noise meter next to the traffic.
Just to measure the different levels that occur
on either side of the wall.
And we found that for 190,
after the wall was completed that with the acrylic panels.
That the noise reduction was about 12 and a half decibels.
Before the panels the difference was 10 decibels.
So, it was an additional noise reduction of about
two and a half decibels.
- [Daniel] A lot of these homes
are right along this highway.
And so there's a lot of traffic noise.
With this wall, it's helped to reduce that traffic noise
for these neighboring properties.
- The lightweight barriers just add flexibility
for TxDOT in the future.
So now if we do have a bridge structure
we can actually build a barrier that's 15 feet tall.
Whereas we would have not built it in the past.
We would have said,
so sorry, we were not able to build this barrier
because of engineering requirements.
- [Manuel] If you have a structure
that you want to retrofit with noise walls.
An acrylic panel solution could be ideal.
- [Narrator] For more information,
and to find the publications for this project.
Please visit the TxDOT research library
at the link shown below.