February 14, 2023 • 29 mins
America’s roads were built to last, but they weren’t built to last forever. New research is taking a forensic approach to maintaining and repairing our surface transportation infrastructure.
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Episode Transcript
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Bernie Fette (host) (00:14):
Hello again.
This is Thinking Transportation-- conversations about how we
get ourselves and the things weneed from one place to another.
I'm Bernie Fette with the TexasA&M Transportation Institute.
If we judge things on appearancealone, it's easy to think that
(00:34):
streets and highways are almostindestructible, strong enough to
bear the weight of countlesscars and trucks day after day
and year after year withoutfail.
And though many of us don'trealize it, there's a lot of
science, chemistry, andengineering that goes into
keeping those driving surfacesin good shape.
(00:56):
That's our topic today with TomScullion, a senior research
engineer at tti, and an expertin pavement maintenance and
repair.
Tom, I know you've been superbusy and you've been traveling a
lot.
We're really grateful you couldmake time to join us today.
Thanks, Tom.
Tom Scullion (guest) (01:14):
My pleasure.
Bernie Fette (01:16):
I know we're gonna try to talk about a number of
new things in your work today,what you can do to help roads
stand up to the vibrant energyindustry in Texas,
environmentally friendly waysto, to repair pavements.
Yep.
I was hoping though, that wecould start at a more basic
level, particularly forlisteners who don't know
(01:37):
anything about road building.
Those of us who don't thinkabout roadway maintenance unless
we run over a pothole.
So can you give us a picture ofthe major steps that go into
building a street or highway?
Tom Scullion (01:50):
Yeah.
Most of my experience, vastmajority of my experience has
been in Texas and I, I thinkwhen we talk about building
roads in Texas, it's not onesize fits all.
We've got a state here with justabout everything.
If you go from east to west-- ineast Texas, you have some really
(02:11):
poor soil conditions and youhave a lot of rainfall.
You go to west Texas and youhave very good soils, very good
subgrade materials, very littlerain.
That's an ideal situation.
You go to south Texas and youhave very pleasant climates.
You go up to the panhandle andwe get several feet of snow.
(02:31):
Mm-hmm.
.
So like I said, road building inTexas is not one size fits all.
Texas is blessed with some ofthe worst soils in the whole
United States.
Uh, that is these expansive claymaterials that we find anywhere
east of Interstate 35.
Okay.
Uh, these are the soils thatwhen they get wet, they expand,
(02:54):
and when they get dry theyshrink and crack.
All of these issues I'm bringingup now are to do with the
challenges of building roads inthe state of Texas.
Bernie Fette (03:04):
Okay.
Tom Scullion (03:05):
Now, road building really started maybe a hundred
years ago, and the big driveback then was to get the farmers
out of the mud.
And the first thing you have todo with these roads that we
built was you have to have astable foundation.
Bernie Fette (03:24):
Okay.
Tom Scullion (03:24):
Now, if you're working on this very poor soils
that we have, how do you get astable foundation?
Well, you have to chemicallytreat it.
So Texas probably uses more limethan the rest of the whole
United States together becauseof the very sorry, nature of the
soils that we have to build iton.
Bernie Fette (03:44):
Okay.
And so you have to do a lot ofthings to that soil.
And when we're talking aboutsoil, we're talking about more
than just the dirt.
You're talking about the clay,you're talking about the rocks
that are in it, the otherorganic matter like roots and
grasses and such.
Yes.
All of the things that you'retalking about have to be done to
make the soil essentially morestable.
Tom Scullion (04:02):
That's right.
Okay.
We need a, a stable foundation.
Right.
To put a road on it.
Now, when we started, the vastmajority of that payment
structure in the rural areas wasthis lime stabilized subgrade
where we needed it, six inchesof limestone material, and then
what was a surface dressing,which is just a shot of asphalt
(04:23):
and a layer of rocks placed ontop.
Okay.
Those things, if they'redesigned properly, really got
the farmers out in the mud, sothat's okay.
Kind of where we started.
Now, the other thing whichdrives the whole payment design
side of things is the amount oftraffic on the roads.
And I'm sure you've heard thestatistic before for the last,
(04:46):
oh, I don't know how many years,there's been a statistic that
there's a thousand people a daymoving to Texas.
Bernie Fette (04:51):
Right, right.
And they all bring their carsand trucks.
Tom Scullion (04:54):
They'll bring in two cars with them.
And so then we have many morevehicles on the roads and
subsequently because of theinflux of people coming here, we
need new roads, but we also neednew buildings and highways and
schools and all this kind ofgood stuff.
So that drives the wholeeconomy, the construction
economy, not just of roads, butof buildings that's putting more
(05:16):
load on the roads that needs tobe, you know, accounted for.
Bernie Fette (05:19):
Because a lot of the same things that you're
using to build roads, you'realso using to build those, those
office buildings.
Yeah.
And schools and such.
Yeah.
Okay.
Tom Scullion (05:27):
The basic road system was really put in for the
farmers, but then when we havethis tremendous growth and then
we have the focus on moving thecities, we've gotta modify
things to handle thosesituations.
Bernie Fette (05:38):
Okay.
So you started out with thisgoal of getting the farmer out
of the mud.
Mm-hmm.
, and we'veproceeded to a more modern Texas
where urban areas are growing atan extremely fast clip.
Mm-hmm.
, uhhuh,.
Those things taken intoconsideration once you've built
that, that stronger foundationfor those roads and put the
(05:59):
surface on them and put thoseroads into use, how long can you
reasonably expect those roadwaysto last before the pavement
needs to be maintained or fixed?
Tom Scullion (06:09):
When these things are initially designed there,
there's two types of pavementsthat you see when you move to
the cities.
One is asphalt pavements, right.
Where we have a layer of theblack stuff, which covers our
base material.
Our base material is usually,typically just a layer of
limestone, aggregates that iscompacted and whatever.
Then we put certain thicknessesof asphalt on top of that.
(06:32):
What has become really popularin the urban areas is the other
type of payment that we see alot of is concrete payments.
Bernie Fette (06:40):
Right.
And you're getting to, one ofthe questions I was hoping to
ask is why we have those twodifferent types.
Tom Scullion (06:45):
The feeling right now with with folks like the
Texas Department ofTransportation is that when we
get into the urban areas, andI'm talking about the urban
areas of Houston, and I'mtalking about the urban areas of
Dallas.
Mm-hmm.
, that's where wehave requirements on there.
Man, man, we want to get inthere.
We want to do whatever we'rebuilding and we don't want to
(07:06):
come back for 30 years.
The consensus is that theconcrete pavements in those
brutal conditions usually holdup better.
Okay.
You know, or give us those longlife.
Now there's a whole history ofroad building in the urban areas
and I think, uh, the TexasDepartment of Transportation has
(07:26):
really done a, a good job ofdesigning payments to last in
those areas.
They go through this foundationstuff again, when you get into
the areas of Houston, becauseHouston's on some pretty poor
soils.
They go with lime stabilizedlayers, uh, base layers, and
then they'll put 12 to 14 inchesof concrete as the wearing
(07:48):
surface.
Mm-hmm.
, those typically,you know, don't give you any
problems till after at least 20years.
Their design life is normally 30years.
That's what they're designedfor.
Bernie Fette (07:59):
Okay.
As opposed to asphalt roadways,which you can expect to last
about how long?
Tom Scullion (08:05):
Normally the asphalt roadways are designed
for 20 years.
Um, and the expectation in thedesign process is you will not
do anything to these roads for15 years.
At 15 years you'll have to dosome resurfacing.
You know, you should just havelike a surfacing problem where
you need to come and redo thesurface of the road because
(08:27):
maybe it's got some minor cracksin it.
Mm-hmm.
, or maybe it isgot some skid resistance type
problems.
So for a national payment,normally in year 15 when they're
built for this urban situation,normally in, in that situation
you'll be coming to do somemilling and a, a new surfacing
after say 15 years.
Bernie Fette (08:47):
You're talking about the differences between
concrete and asphalt pavements,how long they last.
One of the things that a typicaltraveler is probably most
familiar with whenever theyencounter a maintenance issue is
the pothole.
Mm-hmm.
.
Mm-hmm.
.
And so just to give us a littlebit of a engineering 101 or road
(09:07):
maintenance 101 explanation, whydo potholes happen?
Tom Scullion (09:12):
I would say that the main reason is the
combination of, um, overloadedvehicles and bad weather, heavy
rainfall.
And you know, we have a hardtime regulating the loads that
drive on these roads,especially, you know, the energy
sector stuff going on and whathave you.
But sometimes the roads, maybethere were designs for a certain
(09:35):
level of traffic, and we'll talkabout this later too.
And the level of traffic mighthave gone up by a factor of 10
and there's 10 times more loadson the road and what have you.
Now, if we're talking aboutpotholes in asphalt pavements,
normally what happens is becauseof the traffic on it in the
environment and what have you,you get some kind of cracking
going on.
(09:55):
Okay.
Then what happens is you getrainfall going in there, the
surfacing is supposed to protectthe base from wearing out.
Now if that surfacing cracks,you get rain into it, you get
moisture into that limestonebase down there, all things go
bad.
So increased traffic loads,payments that will never
(10:16):
designed for those roads,surface cracking, water getting
in, but you have potholes.
Bernie Fette (10:21):
Right.
And you mentioned the extra loadon roadways that weren't built
to handle those roads.
You specifically mentionedroadways in the energy sector,
Permian Basin and other parts ofTexas as well.
And not just Texas, but anywherein the United States where the
roadways were built for aparticular type of traffic,
(10:42):
perhaps cars and pickups andmaybe the occasional tractor,
but now they're standing up orthose roads are trying to stand
up to much, much heavier loads.
Mm-hmm.
due tocircumstances that were not
foreseen years before when theywere designed and built.
What are some of the challengesthat you're running into there,
especially since those arerelatively recent developments
(11:03):
in Texas and and how have youbeen dealing with those?
Tom Scullion (11:06):
Yeah, that's what I've been dealing with Bernie
for the last 10 years, andthat's when the energy boom
really kicked off in both southTexas and in the Odessa area.
Mm-hmm.
, Permian Basin.
Mm-hmm.
, and as I say,those roads were never built for
the loads that are on them.
The energy guys are what drivesthe economy of Texas.
(11:28):
So we need to, you know,accommodate this stuff.
And so the challenges that wereput in there is that you have a
road that was designed for 500cars a day, and all of a sudden
that road is carrying 500 trucksan hour.
I mean, the roads in both areas,south Texas, in the Odessa area
(11:50):
were totally destroyed.
The farm to market network overthere was totally destroyed.
Mm-hmm.
.
So we got into working with theTexas Department of
Transportation to say, well,what the heck can we do?
Well, TxDOT made the challengeeven more interesting because
they said, okay, you guys, youneed to come up with a fix.
We need to widen these roads, weneed to strengthen these roads.
(12:14):
But the one kicker on top ofthat stuff is whatever you folks
do, we're putting the energysector traffic on it that night.
So whatever repairs you come upwith, you've gotta get outta the
way at five o'clock and we'reputting the energy sector loads
on it.
Bernie Fette (12:29):
So fix it right.
And fix it fast.
Tom Scullion (12:31):
Fix it fast.
That has been what we have beenworking on intently for the last
seven or eight years at least.
And what we do, these are roadsin rural areas where you really
need to figure out how to takethe existing structure and
strengthen it.
But you've also got thatadditional requirement on it of,
(12:54):
you know, um, how can we put thetraffic on it early?
And we're talking about fullyloaded energy sector trucks
here.
Okay.
We're talking about going inthere, doing something to the
road, mixing it up, leveling itout, and then within two hours
putting traffic on it.
The traditional approachesdidn't work.
Bernie Fette (13:09):
And just for a perspective, you were having to
accelerate procedures to adegree.
Yeah.
Leveling things out, fixing it,and two hours later putting
traffic on it in the past, or ifthis was not an energy sector
roadway, how much time would beallowed for the processes that
you're talking about?
Tom Scullion (13:26):
Oh, you can keep the road closed for two or three
days while you get everythinglooking pretty and make sure
everything is gonna hold up andwhat have you.
Bernie Fette (13:34):
Two or three days versus two or three hours.
Yeah.
Tom Scullion (13:36):
Yeah.
This, okay, this, remember whatwe're talking about here is
minor roadways in the boonieswhere there is no detour
available.
Bernie Fette (13:44):
Right.
Tom Scullion (13:44):
And you've got major energy sector development
going on along the route.
Bernie Fette (13:50):
Because time is money.
Tom Scullion (13:51):
Get in there, fix it, and get outta the way.
Right.
There's a challenge.
Okay.
Now what we've been doing andwhat we've promoted and what is
working very well is coming upwith a combination of different
materials.
And this gets into a lot ofthings.
This gets into the whole conceptof improving our pavement
recycling processes.
(14:11):
Mm-hmm.
Recycling is wherewe come and evaluate the
existing structure, mix it allup with a huge reclaimer, put
some kind of stabilizer into it,we will then compact it and roll
it.
We will not put a surfacing onit, but then we'll put the
traffic on it.
So the challenge for us is whatkind of treatment can we apply
(14:33):
to this thing to facilitate thisrehabilitation option?
Bernie Fette (14:37):
So you're grinding up an old roadway, you're mixing
in newer materials, and thenusing that combined product to
build a new driving surface.
Right?
Tom Scullion (14:46):
Yes.
Well, it is gonna eventuallyhave some kind of surfacing on
it.
Okay.
But we want to make it stableenough that we can drive on
whatever we finished at the endof that day.
Bernie Fette (14:57):
Even if it doesn't have an asphalt surface on top.
Tom Scullion (14:59):
It doesn't have an asphalt, it doesn't have a seal
coat.
Nothing.
It's on a treated material.
Bernie Fette (15:03):
You're just driving on the base material.
Tom Scullion (15:05):
That's right.
That's
Bernie Fette (15:06):
Right.
Okay.
Okay.
Tom Scullion (15:07):
Bottom line on what we've been promoting is
that we knew that our, ourstandard stabilizers cement
wouldn't work because it kind ofset up as fast.
So what we've done in the lastseven or eight years at least,
is come up with a combination ofcement in asphalt.
Bernie Fette (15:23):
Mm-hmm.
Tom Scullion (15:23):
, We
have two products.
One is 1% cement and foamedasphalt, and that's just another
story in itself.
Or we have 1% cement and anasphalt emulsion.
We mix these two things togetherand we come up with the best of
both worlds, I think.
Okay.
Because when we do this and wecompact that thing, you gain
(15:46):
strength, the asphalt will helpyou with the waterproofing
because the last thing you wantis to finish the construction
and then you get three inches ofrain that night.
Right.
And then you're putting thesetrucks onto it.
So whatever you do has gottahave the strength and it's gotta
have the ability to shed waterif it gets rained on.
The energy sector is stillbooming and it's still really,
(16:08):
really booming in the Odessaarea.
And I think we put severalhundred million worth of this
material down in the last fiveyears.
They're rebuilding all the roadsin Odessa, and this combination
of fold EPP recycling with anasphalt cement combination is
really working well for thesepeople.
Bernie Fette (16:29):
So I'm hearing you talk about challenges that
current modern road builders arehaving to deal with that were
not an issue more than a centuryago.
Yeah, that's true.
Okay.
On the flip side of that, whatsorts of things did the early
road maintainers have to contendwith that DOTs don't have to
(16:51):
worry about today?
What's the converse?
And yeah.
I'm thinking in part about horsemanure as one example,.
So what were the things fromprevious ages, early days of
road building that we have todaythat they didn't have to contend
with over a hundred years ago?
Tom Scullion (17:09):
Well, I, I'm thinking about the great
advances that have been made,you know, okay, where, where,
where, where are these things?
And I, and I really think theadvances have been made in the
terms of the equipment that wehave available now.
I mean, this maybe is not known,but there's a lot of money in
this road building and makingsure it's permanent.
(17:30):
Um,
Bernie Fette (17:30):
Great.
Let's, let's talk a little aboutthose advancements then.
Yeah.
Specifically in the time thatthis has been your life's work.
Mm-hmm.
, Can you startwith talking a little about
ground penetrating radar?
Talk about that a little bitbecause just the name itself
sounds pretty fascinating andthen you can go from there.
Tom Scullion (17:46):
Yeah.
I've been around this technologysince the late eighties and I
think I, the best way to explainit is to think that we're road
doctors.
What this technology does, iffor a layman's point of view is
X-ray the road, okay.
We can go along at highwayspeed, use this technology to go
(18:07):
and shoot into the pavement totell us what we have there.
And often we go to roadways andwe really, like I say, it might
be a 50 year old road and it'sbeen maintained and there's all
kinds of things going on.
And then we put a very thinsurface over it.
So what's beneath the surfaces?
We've got no clue.
Right.
So we needed a technology thatwould help us get through this
(18:29):
whole process of rebuildingthese roads, strengthen these
roads.
So before you do that, you say,well, what we got, well, we
don't know what we've got.
The last thing you wanna do isget a contractor out there to do
a lot of repair work where he isgonna grind things up and hit a
major change.
You know, and the main benefitsof this technology we're talking
(18:51):
about, the ground penetratingradar is no surprises.
Okay.
We want to fully understand whatwe have beneath the surface so
we can effectively treat it.
The technology itself is veryfascinating because it was
developed by the U.
S.
military in the 1970s for landdetection.
Bernie Fette (19:09):
To, to find landmines.
Okay.
Tom Scullion (19:12):
Yeah.
Now, back in the sixties andseventies, the landmines were
all metal, but they changed frombeing metal in the eighties to
be much smaller plastic mines.
So the military decided that thetechnology, they developed a
very good technology, wasn'tappropriate for the application
they needed, had to move on tosomething else.
(19:33):
Mm-hmm.
.
So that technology was releasedfor applications and that's
where we jumped into it with afew small companies to say,
well, what can we do with thisstuff?
Mm-hmm.
, at the moment, wemount this radar antenna on
front of a vehicle and it's fourfoot in front of the vehicle,
and we travel down the road at70 miles an hour and we can take
(19:53):
a reading every foot as we godown and we can measure the
thickness of the road and we cantell you if there's any defects
in that road beneath thesurface.
We're looking down to about twofoot beneath the surface.
And so we essentially get anx-ray of the road at 70 miles an
hour.
Every one of these pavementrehabilitation strategies or
(20:14):
projects I get involved with, weuse this technology as step
number one.
We have a picture of what theanimal is that we're trying to
rehabilitate here.
Bernie Fette (20:24):
And having those readings is important because
it's the quickest and mostefficient way for you to find
out what is happening below thesurface.
Yeah.
This helps you and thecontractors who are hired to fix
the roadways helps to knowexactly where the problems are
so that you can Yeah.
Put the dollars where they dothe most good, right?
(20:46):
Yes,
Tom Scullion (20:47):
Yes, that's right.
Bernie Fette (20:47):
That's right.
Okay.
Which leads me to the point thatroad building is a pretty
expensive endeavor.
Mm-hmm.
.
So can you talk a little abouthow all of these advancements,
and I know we're talking aboutjust one now, but just this one
for example, how does it help tostretch transportation budgets,
whether we're talking local orstate or federal transportation
budget levels?
Tom Scullion (21:08):
Yeah.
I've been doing this stuff for along time and I think in Texas
we really have put together theset of tools that let you do it
right.
And it's not just us here at theTexas A&M Transportation
Institute.
The technologies we've beendeveloped have been fully
implemented statewide around thestate of Texas.
The main thing Bernie, is man,no surprises.
(21:32):
Okay.
We don't want to get intoprojects, start turning it over
and find out.
It's completely different fromwhat we had.
When you have these kind ofsurprises that you come to on
projects, man that can eat yourlunch, when it comes to getting
these things done the way theyshould be done.
Bernie Fette (21:48):
I mentioned in that last question, something
about the federal transportationdollars.
Mm-hmm.
and speaking ofthe federal level mm-hmm.
Congress passed anambitious piece of legislation.
Yes.
Last year, the InfrastructureInvestment and Jobs Act.
How does that collection ofpolicies address roadway
maintenance in this country?
Tom Scullion (22:10):
Yeah.
We, we will have to see.
The focus of that policy isreally welcome.
I mean, we really need toexplain to the public that man,
the, these roads were designedfor 30 years and a lot of these
roads out there and now 60 yearsold, they've lasted a lot
longer.
And they're held together withband-aids is what?
(22:31):
What's happening without theemphasis put on it by this
policy, you know that DOTs willnever have enough money to do
everything they need to do.
So what they do with these olderroads is they put band-aids on
them, which means that they haveto come back every three to five
years instead of having themmoney to fix them properly.
Right.
So that's what you see a lot of,Bernie, going on there, is that
(22:53):
you have a road that's crackedup.
We go out and do the design andwe give them two options.
We say, well, if you want abandaid to hold this thing
together for four years, I cangive you that.
But if you really want to fixthis thing for 20 years, you've
gotta spend a lot more money.
Well, that money was neveravailable.
Now the fact that the feds havecome in there and you know,
(23:16):
encouraged a thoroughinvestigation that's really
welcome.
But whether we'll ever haveenough money to do all the
fixing that we need to do,that's another question.
Bernie Fette (23:24):
Because the, the roads we're talking about, they
were definitely built to last,but they were not built to last
forever.
Tom Scullion (23:30):
Well, just the length of time and the amount of
traffic on them with the issuesof the number of people coming
to Texas, and then with theissues of the special
development, energy sectordevelopment, agricultural
development, and all this otherthings, the amount of traffic
and the loads of traffic haveall increased substantially.
They were designed 30, 40 yearsago.
(23:51):
They were never in design forthat level of traffic.
Bernie Fette (23:54):
So much of what we've touched on, we could do
several hours of discussion onall of this.
I know, Tom.
So as I'm trying to wrap up ourconversation, I'm, I'm
wondering, can you share yourthoughts on what you see as
being the biggest research needsfor the near future?
We've talked a little aboutadvancements over the past
several decades.
(24:14):
Where is the next big thinglikely to come from?
Tom Scullion (24:18):
Of course, Bernie, the big thing for the next 10
years is gonna be thisenvironmental stuff, this carbon
footprint.
How do we change our wholeoperation to give us a smaller
carbon footprint?
So the whole industry needs tolook at this whole environmental
side of things now.
(24:39):
Mm-hmm.
, I think justadding on to what we spoke about
earlier, where we contribute onthat area, there has to be
worked on materials andwhatever, but you think of the
carbon footprint from rebuildingroads where you take everything
away and build a new road towhat I've been telling you
earlier, which is recycling.
Mm-hmm.
(24:59):
, I think there'sgonna be a big boom in this area
of recycling.
You know, when the road wearsout, one of the things you can
do is get rid of the whole roadand then build a new one.
Mm-hmm.
.
Well that takes a lot of energy.
You've gotta know the materials,you've gotta take'em away.
You've gotta bring new materialsin, you've gotta mine them.
Well, there's a lot of energyand a lot of cost there.
Bernie Fette (25:19):
And a lot of environmental implications.
Tom Scullion (25:22):
Yes.
If you can do what I'm talkingabout, which is look at the
existing roadway with thetechnologies we have.
Look at ground penetratingradar, falling weight,
deflectometer, and come up witha very good long-lasting design
by grinding up what's there andtreating it.
Somehow the environmental impactis minimal compared with the
full reconstruction process.
(25:42):
So I think very, that's thefocus and the future because of
the federal push and you know,this is the global warming and
all this kind of stuff going onhere.
It really is gonna come impactthe road building industry.
Bernie Fette (25:56):
Lastly, Tom, what is it that keeps you showing up
to work every day?
Tom Scullion (26:02):
Well, maybe I fooled a lot of people over the
years, or sounding, but a lot ofpeople think I know what I'm
talking about.
Maybe it's my funny accent.
They told me that 50 years ago,Bernie, that this thing is gonna
peter out.
And I'm still here, man, and I'mstill busier now than I was 50
years ago.
I've got to the position wherepeople trust me.
Mm-hmm.
, and whenever wehave a problem, if something
(26:25):
doesn't hold up, it was designedfor 20 years and we're seeing
problems in five years and we'reseeing problems in two years.
I get called in to do what'scalled forensic investigations.
We did one just this week in theOdessa District, and these are
the challenging things whereroadways fail.
If roadways never fail, youdon't learn anything.
(26:46):
But if a roadway is supposed tolast 20 years and you have
problems in one year, you go inand figure out what the heck
happened here.
Mm-hmm.
.
So I do about one of these amonth, and that's truly where we
learn things.
If the road is designed for 20years, you build in and it
performs perfectly.
You don't learn anything.
A lot of the advances we've madein the last 15 years has been
(27:12):
caused by digging into failures,understanding the failures, and
implementing changes so itdoesn't happen again.
That's why I come to work,because I do a lot of these
forensics, and when we do theseforensics investigations, that's
where we learn things.
Bernie Fette (27:28):
We've been visiting with Tom Scullion, a
senior research engineer at tti,and by his own definition, one
of the road doctors who isworking to keep your daily
travels is smooth and potholefree as possible.
Tom, thanks very much for beingwith us.
This has been fascinating.
Tom Scullion (27:48):
Alright, thank you Bernie.
Bernie Fette (27:50):
The process of building a roadway seems simple
enough.
Lay out the base material andcover it with asphalt.
But keeping those pathways ingood condition is far more
complicated than it mightappear.
Maintaining a stabletransportation infrastructure
requires careful investment andscientific precision.
(28:12):
Because the roads and bridges wedrive upon every day were
certainly built to last, butthey were not built to last
forever.
Thanks for listening.
Please take just a minute togive us a review, subscribe and
share this episode, and we hopeyou'll join us again next time
for a conversation with TimLomax.
(28:33):
When Tim was a young boy, hismother told him to go out and
play on a freeway.
He used that advice to launch a46-year career in transportation
research thinking Transportationis a production of the Texas A&M
Transportation Institute, amember of the Texas A&M
University System.
(28:53):
The show is edited and producedby Chris Pourteau.
I'm your writer and host, BernieFette.
Thanks again for listening.
We'll see you next time.
Hello again.
This is Thinking Transportation-- conversations about how we
get ourselves and the things weneed from one place to another.
I'm Bernie Fette with the TexasA&M Transportation Institute.
If we judge things on appearancealone, it's easy to think that
(00:34):
streets and highways are almostindestructible, strong enough to
bear the weight of countlesscars and trucks day after day
and year after year withoutfail.
And though many of us don'trealize it, there's a lot of
science, chemistry, andengineering that goes into
keeping those driving surfacesin good shape.
(00:56):
That's our topic today with TomScullion, a senior research
engineer at tti, and an expertin pavement maintenance and
repair.
Tom, I know you've been superbusy and you've been traveling a
lot.
We're really grateful you couldmake time to join us today.
Thanks, Tom.
Tom Scullion (guest) (01:14):
My pleasure.
Bernie Fette (01:16):
I know we're gonna try to talk about a number of
new things in your work today,what you can do to help roads
stand up to the vibrant energyindustry in Texas,
environmentally friendly waysto, to repair pavements.
Yep.
I was hoping though, that wecould start at a more basic
level, particularly forlisteners who don't know
(01:37):
anything about road building.
Those of us who don't thinkabout roadway maintenance unless
we run over a pothole.
So can you give us a picture ofthe major steps that go into
building a street or highway?
Tom Scullion (01:50):
Yeah.
Most of my experience, vastmajority of my experience has
been in Texas and I, I thinkwhen we talk about building
roads in Texas, it's not onesize fits all.
We've got a state here with justabout everything.
If you go from east to west-- ineast Texas, you have some really
(02:11):
poor soil conditions and youhave a lot of rainfall.
You go to west Texas and youhave very good soils, very good
subgrade materials, very littlerain.
That's an ideal situation.
You go to south Texas and youhave very pleasant climates.
You go up to the panhandle andwe get several feet of snow.
(02:31):
Mm-hmm.
So like I said, road building inTexas is not one size fits all.
Texas is blessed with some ofthe worst soils in the whole
United States.
Uh, that is these expansive claymaterials that we find anywhere
east of Interstate 35.
Okay.
Uh, these are the soils thatwhen they get wet, they expand,
(02:54):
and when they get dry theyshrink and crack.
All of these issues I'm bringingup now are to do with the
challenges of building roads inthe state of Texas.
Bernie Fette (03:04):
Okay.
Tom Scullion (03:05):
Now, road building really started maybe a hundred
years ago, and the big driveback then was to get the farmers
out of the mud.
And the first thing you have todo with these roads that we
built was you have to have astable foundation.
Bernie Fette (03:24):
Okay.
Tom Scullion (03:24):
Now, if you're working on this very poor soils
that we have, how do you get astable foundation?
Well, you have to chemicallytreat it.
So Texas probably uses more limethan the rest of the whole
United States together becauseof the very sorry, nature of the
soils that we have to build iton.
Bernie Fette (03:44):
Okay.
And so you have to do a lot ofthings to that soil.
And when we're talking aboutsoil, we're talking about more
than just the dirt.
You're talking about the clay,you're talking about the rocks
that are in it, the otherorganic matter like roots and
grasses and such.
Yes.
All of the things that you'retalking about have to be done to
make the soil essentially morestable.
Tom Scullion (04:02):
That's right.
Okay.
We need a, a stable foundation.
Right.
To put a road on it.
Now, when we started, the vastmajority of that payment
structure in the rural areas wasthis lime stabilized subgrade
where we needed it, six inchesof limestone material, and then
what was a surface dressing,which is just a shot of asphalt
(04:23):
and a layer of rocks placed ontop.
Okay.
Those things, if they'redesigned properly, really got
the farmers out in the mud, sothat's okay.
Kind of where we started.
Now, the other thing whichdrives the whole payment design
side of things is the amount oftraffic on the roads.
And I'm sure you've heard thestatistic before for the last,
(04:46):
oh, I don't know how many years,there's been a statistic that
there's a thousand people a daymoving to Texas.
Bernie Fette (04:51):
Right, right.
And they all bring their carsand trucks.
Tom Scullion (04:54):
They'll bring in two cars with them.
And so then we have many morevehicles on the roads and
subsequently because of theinflux of people coming here, we
need new roads, but we also neednew buildings and highways and
schools and all this kind ofgood stuff.
So that drives the wholeeconomy, the construction
economy, not just of roads, butof buildings that's putting more
(05:16):
load on the roads that needs tobe, you know, accounted for.
Bernie Fette (05:19):
Because a lot of the same things that you're
using to build roads, you'realso using to build those, those
office buildings.
Yeah.
And schools and such.
Yeah.
Okay.
Tom Scullion (05:27):
The basic road system was really put in for the
farmers, but then when we havethis tremendous growth and then
we have the focus on moving thecities, we've gotta modify
things to handle thosesituations.
Bernie Fette (05:38):
Okay.
So you started out with thisgoal of getting the farmer out
of the mud.
Mm-hmm.
where urban areas are growing atan extremely fast clip.
Mm-hmm.
Those things taken intoconsideration once you've built
that, that stronger foundationfor those roads and put the
(05:59):
surface on them and put thoseroads into use, how long can you
reasonably expect those roadwaysto last before the pavement
needs to be maintained or fixed?
Tom Scullion (06:09):
When these things are initially designed there,
there's two types of pavementsthat you see when you move to
the cities.
One is asphalt pavements, right.
Where we have a layer of theblack stuff, which covers our
base material.
Our base material is usually,typically just a layer of
limestone, aggregates that iscompacted and whatever.
Then we put certain thicknessesof asphalt on top of that.
(06:32):
What has become really popularin the urban areas is the other
type of payment that we see alot of is concrete payments.
Bernie Fette (06:40):
Right.
And you're getting to, one ofthe questions I was hoping to
ask is why we have those twodifferent types.
Tom Scullion (06:45):
The feeling right now with with folks like the
Texas Department ofTransportation is that when we
get into the urban areas, andI'm talking about the urban
areas of Houston, and I'mtalking about the urban areas of
Dallas.
Mm-hmm.
Man, man, we want to get inthere.
We want to do whatever we'rebuilding and we don't want to
(07:06):
come back for 30 years.
The consensus is that theconcrete pavements in those
brutal conditions usually holdup better.
Okay.
You know, or give us those longlife.
Now there's a whole history ofroad building in the urban areas
and I think, uh, the TexasDepartment of Transportation has
(07:26):
really done a, a good job ofdesigning payments to last in
those areas.
They go through this foundationstuff again, when you get into
the areas of Houston, becauseHouston's on some pretty poor
soils.
They go with lime stabilizedlayers, uh, base layers, and
then they'll put 12 to 14 inchesof concrete as the wearing
(07:48):
surface.
Mm-hmm.
problems till after at least 20years.
Their design life is normally 30years.
That's what they're designedfor.
Bernie Fette (07:59):
Okay.
As opposed to asphalt roadways,which you can expect to last
about how long?
Tom Scullion (08:05):
Normally the asphalt roadways are designed
for 20 years.
Um, and the expectation in thedesign process is you will not
do anything to these roads for15 years.
At 15 years you'll have to dosome resurfacing.
You know, you should just havelike a surfacing problem where
you need to come and redo thesurface of the road because
(08:27):
maybe it's got some minor cracksin it.
Mm-hmm.
problems.
So for a national payment,normally in year 15 when they're
built for this urban situation,normally in, in that situation
you'll be coming to do somemilling and a, a new surfacing
after say 15 years.
Bernie Fette (08:47):
You're talking about the differences between
concrete and asphalt pavements,how long they last.
One of the things that a typicaltraveler is probably most
familiar with whenever theyencounter a maintenance issue is
the pothole.
Mm-hmm.
Mm-hmm.
And so just to give us a littlebit of a engineering 101 or road
(09:07):
maintenance 101 explanation, whydo potholes happen?
Tom Scullion (09:12):
I would say that the main reason is the
combination of, um, overloadedvehicles and bad weather, heavy
rainfall.
And you know, we have a hardtime regulating the loads that
drive on these roads,especially, you know, the energy
sector stuff going on and whathave you.
But sometimes the roads, maybethere were designs for a certain
(09:35):
level of traffic, and we'll talkabout this later too.
And the level of traffic mighthave gone up by a factor of 10
and there's 10 times more loadson the road and what have you.
Now, if we're talking aboutpotholes in asphalt pavements,
normally what happens is becauseof the traffic on it in the
environment and what have you,you get some kind of cracking
going on.
(09:55):
Okay.
Then what happens is you getrainfall going in there, the
surfacing is supposed to protectthe base from wearing out.
Now if that surfacing cracks,you get rain into it, you get
moisture into that limestonebase down there, all things go
bad.
So increased traffic loads,payments that will never
(10:16):
designed for those roads,surface cracking, water getting
in, but you have potholes.
Bernie Fette (10:21):
Right.
And you mentioned the extra loadon roadways that weren't built
to handle those roads.
You specifically mentionedroadways in the energy sector,
Permian Basin and other parts ofTexas as well.
And not just Texas, but anywherein the United States where the
roadways were built for aparticular type of traffic,
(10:42):
perhaps cars and pickups andmaybe the occasional tractor,
but now they're standing up orthose roads are trying to stand
up to much, much heavier loads.
Mm-hmm.
foreseen years before when theywere designed and built.
What are some of the challengesthat you're running into there,
especially since those arerelatively recent developments
(11:03):
in Texas and and how have youbeen dealing with those?
Tom Scullion (11:06):
Yeah, that's what I've been dealing with Bernie
for the last 10 years, andthat's when the energy boom
really kicked off in both southTexas and in the Odessa area.
Mm-hmm.
Mm-hmm.
the loads that are on them.
The energy guys are what drivesthe economy of Texas.
(11:28):
So we need to, you know,accommodate this stuff.
And so the challenges that wereput in there is that you have a
road that was designed for 500cars a day, and all of a sudden
that road is carrying 500 trucksan hour.
I mean, the roads in both areas,south Texas, in the Odessa area
(11:50):
were totally destroyed.
The farm to market network overthere was totally destroyed.
Mm-hmm.
So we got into working with theTexas Department of
Transportation to say, well,what the heck can we do?
Well, TxDOT made the challengeeven more interesting because
they said, okay, you guys, youneed to come up with a fix.
We need to widen these roads, weneed to strengthen these roads.
(12:14):
But the one kicker on top ofthat stuff is whatever you folks
do, we're putting the energysector traffic on it that night.
So whatever repairs you come upwith, you've gotta get outta the
way at five o'clock and we'reputting the energy sector loads
on it.
Bernie Fette (12:29):
So fix it right.
And fix it fast.
Tom Scullion (12:31):
Fix it fast.
That has been what we have beenworking on intently for the last
seven or eight years at least.
And what we do, these are roadsin rural areas where you really
need to figure out how to takethe existing structure and
strengthen it.
But you've also got thatadditional requirement on it of,
(12:54):
you know, um, how can we put thetraffic on it early?
And we're talking about fullyloaded energy sector trucks
here.
Okay.
We're talking about going inthere, doing something to the
road, mixing it up, leveling itout, and then within two hours
putting traffic on it.
The traditional approachesdidn't work.
Bernie Fette (13:09):
And just for a perspective, you were having to
accelerate procedures to adegree.
Yeah.
Leveling things out, fixing it,and two hours later putting
traffic on it in the past, or ifthis was not an energy sector
roadway, how much time would beallowed for the processes that
you're talking about?
Tom Scullion (13:26):
Oh, you can keep the road closed for two or three
days while you get everythinglooking pretty and make sure
everything is gonna hold up andwhat have you.
Bernie Fette (13:34):
Two or three days versus two or three hours.
Yeah.
Tom Scullion (13:36):
Yeah.
This, okay, this, remember whatwe're talking about here is
minor roadways in the boonieswhere there is no detour
available.
Bernie Fette (13:44):
Right.
Tom Scullion (13:44):
And you've got major energy sector development
going on along the route.
Bernie Fette (13:50):
Because time is money.
Tom Scullion (13:51):
Get in there, fix it, and get outta the way.
Right.
There's a challenge.
Okay.
Now what we've been doing andwhat we've promoted and what is
working very well is coming upwith a combination of different
materials.
And this gets into a lot ofthings.
This gets into the whole conceptof improving our pavement
recycling processes.
(14:11):
Mm-hmm.
existing structure, mix it allup with a huge reclaimer, put
some kind of stabilizer into it,we will then compact it and roll
it.
We will not put a surfacing onit, but then we'll put the
traffic on it.
So the challenge for us is whatkind of treatment can we apply
(14:33):
to this thing to facilitate thisrehabilitation option?
Bernie Fette (14:37):
So you're grinding up an old roadway, you're mixing
in newer materials, and thenusing that combined product to
build a new driving surface.
Right?
Tom Scullion (14:46):
Yes.
Well, it is gonna eventuallyhave some kind of surfacing on
it.
Okay.
But we want to make it stableenough that we can drive on
whatever we finished at the endof that day.
Bernie Fette (14:57):
Even if it doesn't have an asphalt surface on top.
Tom Scullion (14:59):
It doesn't have an asphalt, it doesn't have a seal
coat.
Nothing.
It's on a treated material.
Bernie Fette (15:03):
You're just driving on the base material.
Tom Scullion (15:05):
That's right.
That's
Bernie Fette (15:06):
Right.
Okay.
Okay.
Tom Scullion (15:07):
Bottom line on what we've been promoting is
that we knew that our, ourstandard stabilizers cement
wouldn't work because it kind ofset up as fast.
So what we've done in the lastseven or eight years at least,
is come up with a combination ofcement in asphalt.
Bernie Fette (15:23):
Mm-hmm.
Tom Scullion (15:23):
One is 1% cement and foamedasphalt, and that's just another
story in itself.
Or we have 1% cement and anasphalt emulsion.
We mix these two things togetherand we come up with the best of
both worlds, I think.
Okay.
Because when we do this and wecompact that thing, you gain
(15:46):
strength, the asphalt will helpyou with the waterproofing
because the last thing you wantis to finish the construction
and then you get three inches ofrain that night.
Right.
And then you're putting thesetrucks onto it.
So whatever you do has gottahave the strength and it's gotta
have the ability to shed waterif it gets rained on.
The energy sector is stillbooming and it's still really,
(16:08):
really booming in the Odessaarea.
And I think we put severalhundred million worth of this
material down in the last fiveyears.
They're rebuilding all the roadsin Odessa, and this combination
of fold EPP recycling with anasphalt cement combination is
really working well for thesepeople.
Bernie Fette (16:29):
So I'm hearing you talk about challenges that
current modern road builders arehaving to deal with that were
not an issue more than a centuryago.
Yeah, that's true.
Okay.
On the flip side of that, whatsorts of things did the early
road maintainers have to contendwith that DOTs don't have to
(16:51):
worry about today?
What's the converse?
And yeah.
I'm thinking in part about horsemanure as one example,
So what were the things fromprevious ages, early days of
road building that we have todaythat they didn't have to contend
with over a hundred years ago?
Tom Scullion (17:09):
Well, I, I'm thinking about the great
advances that have been made,you know, okay, where, where,
where, where are these things?
And I, and I really think theadvances have been made in the
terms of the equipment that wehave available now.
I mean, this maybe is not known,but there's a lot of money in
this road building and makingsure it's permanent.
(17:30):
Um,
Bernie Fette (17:30):
Great.
Let's, let's talk a little aboutthose advancements then.
Yeah.
Specifically in the time thatthis has been your life's work.
Mm-hmm.
ground penetrating radar?
Talk about that a little bitbecause just the name itself
sounds pretty fascinating andthen you can go from there.
Tom Scullion (17:46):
Yeah.
I've been around this technologysince the late eighties and I
think I, the best way to explainit is to think that we're road
doctors.
What this technology does, iffor a layman's point of view is
X-ray the road, okay.
We can go along at highwayspeed, use this technology to go
(18:07):
and shoot into the pavement totell us what we have there.
And often we go to roadways andwe really, like I say, it might
be a 50 year old road and it'sbeen maintained and there's all
kinds of things going on.
And then we put a very thinsurface over it.
So what's beneath the surfaces?
We've got no clue.
Right.
So we needed a technology thatwould help us get through this
(18:29):
whole process of rebuildingthese roads, strengthen these
roads.
So before you do that, you say,well, what we got, well, we
don't know what we've got.
The last thing you wanna do isget a contractor out there to do
a lot of repair work where he isgonna grind things up and hit a
major change.
You know, and the main benefitsof this technology we're talking
(18:51):
about, the ground penetratingradar is no surprises.
Okay.
We want to fully understand whatwe have beneath the surface so
we can effectively treat it.
The technology itself is veryfascinating because it was
developed by the U.
S.
military in the 1970s for landdetection.
Bernie Fette (19:09):
To, to find landmines.
Okay.
Tom Scullion (19:12):
Yeah.
Now, back in the sixties andseventies, the landmines were
all metal, but they changed frombeing metal in the eighties to
be much smaller plastic mines.
So the military decided that thetechnology, they developed a
very good technology, wasn'tappropriate for the application
they needed, had to move on tosomething else.
(19:33):
Mm-hmm.
So that technology was releasedfor applications and that's
where we jumped into it with afew small companies to say,
well, what can we do with thisstuff?
Mm-hmm.
front of a vehicle and it's fourfoot in front of the vehicle,
and we travel down the road at70 miles an hour and we can take
(19:53):
a reading every foot as we godown and we can measure the
thickness of the road and we cantell you if there's any defects
in that road beneath thesurface.
We're looking down to about twofoot beneath the surface.
And so we essentially get anx-ray of the road at 70 miles an
hour.
Every one of these pavementrehabilitation strategies or
(20:14):
projects I get involved with, weuse this technology as step
number one.
We have a picture of what theanimal is that we're trying to
rehabilitate here.
Bernie Fette (20:24):
And having those readings is important because
it's the quickest and mostefficient way for you to find
out what is happening below thesurface.
Yeah.
This helps you and thecontractors who are hired to fix
the roadways helps to knowexactly where the problems are
so that you can Yeah.
Put the dollars where they dothe most good, right?
(20:46):
Yes,
Tom Scullion (20:47):
Yes, that's right.
Bernie Fette (20:47):
That's right.
Okay.
Which leads me to the point thatroad building is a pretty
expensive endeavor.
Mm-hmm.
So can you talk a little abouthow all of these advancements,
and I know we're talking aboutjust one now, but just this one
for example, how does it help tostretch transportation budgets,
whether we're talking local orstate or federal transportation
budget levels?
Tom Scullion (21:08):
Yeah.
I've been doing this stuff for along time and I think in Texas
we really have put together theset of tools that let you do it
right.
And it's not just us here at theTexas A&M Transportation
Institute.
The technologies we've beendeveloped have been fully
implemented statewide around thestate of Texas.
The main thing Bernie, is man,no surprises.
(21:32):
Okay.
We don't want to get intoprojects, start turning it over
and find out.
It's completely different fromwhat we had.
When you have these kind ofsurprises that you come to on
projects, man that can eat yourlunch, when it comes to getting
these things done the way theyshould be done.
Bernie Fette (21:48):
I mentioned in that last question, something
about the federal transportationdollars.
Mm-hmm.
Yes.
Last year, the InfrastructureInvestment and Jobs Act.
How does that collection ofpolicies address roadway
maintenance in this country?
Tom Scullion (22:10):
Yeah.
We, we will have to see.
The focus of that policy isreally welcome.
I mean, we really need toexplain to the public that man,
the, these roads were designedfor 30 years and a lot of these
roads out there and now 60 yearsold, they've lasted a lot
longer.
And they're held together withband-aids is what?
(22:31):
What's happening without theemphasis put on it by this
policy, you know that DOTs willnever have enough money to do
everything they need to do.
So what they do with these olderroads is they put band-aids on
them, which means that they haveto come back every three to five
years instead of having themmoney to fix them properly.
Right.
So that's what you see a lot of,Bernie, going on there, is that
(22:53):
you have a road that's crackedup.
We go out and do the design andwe give them two options.
We say, well, if you want abandaid to hold this thing
together for four years, I cangive you that.
But if you really want to fixthis thing for 20 years, you've
gotta spend a lot more money.
Well, that money was neveravailable.
Now the fact that the feds havecome in there and you know,
(23:16):
encouraged a thoroughinvestigation that's really
welcome.
But whether we'll ever haveenough money to do all the
fixing that we need to do,that's another question.
Bernie Fette (23:24):
Because the, the roads we're talking about, they
were definitely built to last,but they were not built to last
forever.
Tom Scullion (23:30):
Well, just the length of time and the amount of
traffic on them with the issuesof the number of people coming
to Texas, and then with theissues of the special
development, energy sectordevelopment, agricultural
development, and all this otherthings, the amount of traffic
and the loads of traffic haveall increased substantially.
They were designed 30, 40 yearsago.
(23:51):
They were never in design forthat level of traffic.
Bernie Fette (23:54):
So much of what we've touched on, we could do
several hours of discussion onall of this.
I know, Tom.
So as I'm trying to wrap up ourconversation, I'm, I'm
wondering, can you share yourthoughts on what you see as
being the biggest research needsfor the near future?
We've talked a little aboutadvancements over the past
several decades.
(24:14):
Where is the next big thinglikely to come from?
Tom Scullion (24:18):
Of course, Bernie, the big thing for the next 10
years is gonna be thisenvironmental stuff, this carbon
footprint.
How do we change our wholeoperation to give us a smaller
carbon footprint?
So the whole industry needs tolook at this whole environmental
side of things now.
(24:39):
Mm-hmm.
earlier, where we contribute onthat area, there has to be
worked on materials andwhatever, but you think of the
carbon footprint from rebuildingroads where you take everything
away and build a new road towhat I've been telling you
earlier, which is recycling.
Mm-hmm.
(24:59):
of recycling.
You know, when the road wearsout, one of the things you can
do is get rid of the whole roadand then build a new one.
Mm-hmm.
Well that takes a lot of energy.
You've gotta know the materials,you've gotta take'em away.
You've gotta bring new materialsin, you've gotta mine them.
Well, there's a lot of energyand a lot of cost there.
Bernie Fette (25:19):
And a lot of environmental implications.
Tom Scullion (25:22):
Yes.
If you can do what I'm talkingabout, which is look at the
existing roadway with thetechnologies we have.
Look at ground penetratingradar, falling weight,
deflectometer, and come up witha very good long-lasting design
by grinding up what's there andtreating it.
Somehow the environmental impactis minimal compared with the
full reconstruction process.
(25:42):
So I think very, that's thefocus and the future because of
the federal push and you know,this is the global warming and
all this kind of stuff going onhere.
It really is gonna come impactthe road building industry.
Bernie Fette (25:56):
Lastly, Tom, what is it that keeps you showing up
to work every day?
Tom Scullion (26:02):
Well, maybe I fooled a lot of people over the
years, or sounding, but a lot ofpeople think I know what I'm
talking about.
Maybe it's my funny accent.
They told me that 50 years ago,Bernie, that this thing is gonna
peter out.
And I'm still here, man, and I'mstill busier now than I was 50
years ago.
I've got to the position wherepeople trust me.
Mm-hmm.
(26:25):
doesn't hold up, it was designedfor 20 years and we're seeing
problems in five years and we'reseeing problems in two years.
I get called in to do what'scalled forensic investigations.
We did one just this week in theOdessa District, and these are
the challenging things whereroadways fail.
If roadways never fail, youdon't learn anything.
(26:46):
But if a roadway is supposed tolast 20 years and you have
problems in one year, you go inand figure out what the heck
happened here.
Mm-hmm.
So I do about one of these amonth, and that's truly where we
learn things.
If the road is designed for 20years, you build in and it
performs perfectly.
You don't learn anything.
A lot of the advances we've madein the last 15 years has been
(27:12):
caused by digging into failures,understanding the failures, and
implementing changes so itdoesn't happen again.
That's why I come to work,because I do a lot of these
forensics, and when we do theseforensics investigations, that's
where we learn things.
Bernie Fette (27:28):
We've been visiting with Tom Scullion, a
senior research engineer at tti,and by his own definition, one
of the road doctors who isworking to keep your daily
travels is smooth and potholefree as possible.
Tom, thanks very much for beingwith us.
This has been fascinating.
Tom Scullion (27:48):
Alright, thank you Bernie.
Bernie Fette (27:50):
The process of building a roadway seems simple
enough.
Lay out the base material andcover it with asphalt.
But keeping those pathways ingood condition is far more
complicated than it mightappear.
Maintaining a stabletransportation infrastructure
requires careful investment andscientific precision.
(28:12):
Because the roads and bridges wedrive upon every day were
certainly built to last, butthey were not built to last
forever.
Thanks for listening.
Please take just a minute togive us a review, subscribe and
share this episode, and we hopeyou'll join us again next time
for a conversation with TimLomax.
(28:33):
When Tim was a young boy, hismother told him to go out and
play on a freeway.
He used that advice to launch a46-year career in transportation
research thinking Transportationis a production of the Texas A&M
Transportation Institute, amember of the Texas A&M
University System.
(28:53):
The show is edited and producedby Chris Pourteau.
I'm your writer and host, BernieFette.
Thanks again for listening.
We'll see you next time.
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