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(logo whooshing)

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(gentle foreboding music)

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- [Narrator] Crash tests were performed

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on a new guardrail
system that was designed

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to solve a specific problem.

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(truck crashes)

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TxDOT wanted researchers to see

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if a lightweight guardrail
system could be developed

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that would meet new testing standards.

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- Ultimately, we were trying to prevent

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or reduce cross-median crashes.

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- Whenever you have two
opposing lanes of traffic

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that are close to one another,

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it's always a good
practice to have a barrier

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installed between them.

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That prevents traffic from one side,

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somebody from one side to accidentally

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come into the opposing lane of traffic

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and result in a head-on crash,

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and these are crossover crashes,
and they're usually fatal.

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- We have a concrete barrier

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that does that, but we have some bridges

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that can't support the
weight of a concrete barrier

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and this rail, this median
rail will be lightweight

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and prevent the cross-median crashes.

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- [Nauman] We looked at the
existing metal guardrail systems

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and we kind of used as much of the design

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as there is already and
then adapted it for use

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on top of the surface.

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In our design, we had a rail system

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that's also supported by posts,

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but these posts are now just
bolted onto the concrete.

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A key design aspect for this system

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was to look at how the post detaches

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or deforms where it is attached

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to the concrete.

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It is important to have the right release

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of that post or right
defamation of that post,

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if it deforms too quick, if
the connection is too weak,

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then your whole guardrail
will be very weak

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and it might not actually
prevent the vehicle

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from breaching and going
to the opposing lanes.

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And at the same time, if
that connection is too stiff

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or doesn't release quickly,

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then you would have a very stiff system,

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and that can lead to the
vehicle kind of snagging

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onto the barrier, resulting in a rollover,

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or it may just cause rupture to the rail

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or something like that.

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- [Christopher] We tested
to MASH Test Level 3.

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So, we tested a small
car and a pickup truck

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on the median rail, both
passed with flying colors,

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it looked really good.

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- [Nauman] We expect this design

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to be more cost effective
than concrete barriers,

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and at the same time it's
going to be much lighter

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than a concrete barrier, so it can be used

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on top of bridges and also
on concrete pavements.

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- [Narrator] For more information

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and to find the publications
for this project,

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please visit the TxDOT research library

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at the link shown below.