Not So Fast! Can driver behavior influence how speed limits are set?

Factors that determine speed limits on a given roadway have a lot to do with physical conditions along the route, but how fast drivers want to go figures into the equation, too.

Episode Transcript

Bernie Fette (00:14):
Hey everyone.
Welcome to thinkingTransportation. Conversations
about how we get ourselves andthe stuff we need from one
place to another. I'm BernieFette with the Texas A&M
Transportation Institute. Asoperators of motor vehicles, we
are required to comply with avariety of traffic laws --
which side of the street todrive on, when to stop, when to

(00:38):
go. Of all the many rules ofthe road, however, only one --
the speed limit -- allows us asay as drivers. A chance to
offer input. That's right. Theprocess that determines what a
speed limit will be takes intoaccount what we would call
"reasonable and prudentbehavior" on the part of the

(01:00):
drivers who will use aparticular road. Here to help
us understand that practice,and the other considerations
that go into setting speedlimits, is Marcus Brewer, a
research engineer at TTI. Hey,Marcus, really glad you could
join us because this is a topicI've been wanting to cover for
a while.

Marcus Brewer (01:20):
Thanks, Bernie .
Appreciate the invitation.

Bernie Fette (01:23):
All of us who drive know that traffic laws
place restrictions on how fastwe can drive, but what most of
us don't know, however , is howthose speed limits are
determined, how they're set.
And that's what I'm hoping wecan unwrap today. Let's imagine
a brand new road, and on theday it opens, drivers see that

(01:46):
the speed limit is 50 miles anhour. Who decided that the
speed limit was gonna be 50miles an hour? Not 70, not 40.
Who decided that?

Marcus Brewer (01:55):
Well, the road agency, whoever it is that's
responsible for that road ingeneral is who makes that
decision. And there's a lot ofdetails associated with that.
But that decision then is basedon how the road is designed in
many cases, what theanticipated use of that road is
gonna be, and therefore that'sreflected in the design of that

(02:16):
road, how many lanes it's gonnahave, what kind of curves it's
gonna have, hills, and how manydriveways, intersections it's
probably gonna have.

Bernie Fette (02:25):
Okay. You're getting into some of the
features of that road now,which I think is really helpful
. Mm-Hmm . . Sowithout actually seeing that
road, knowing only that thespeed limit is 50, can you draw
from your knowledge just totell us what that road looks
like? You know, the , you wereabout to get into number of
lanes, whether or not thecurves Mm-Hmm . .
So what does a 50 mile an hourroad look like?

Marcus Brewer (02:47):
Well, there's probably in , at least in this
part of the country withinTexas, there's probably gonna
be a couple of different thingsthat's gonna look like. But
generally it's probably goingto be in an area that we would
call suburban or rural type offeel. Mm-Hmm. ,
it's probably going to be aroadway that doesn't have a lot

(03:07):
of development, so not a lot ofhouses, businesses, et cetera .
The , the number of driveways,intersections, is probably
going to be low. Mm-Hmm . It'sprobably going to have either
one or two lanes in eachdirection of travel, depending
on what the expected volume iswhen it opens. And in the
foreseeable future for whatit's designed for. And probably

(03:30):
with a speed limit of 50, it'sgonna maybe have some
curvature, but it's not gonnabe very sharp. Obviously you
wanna be able to have analignment that people can drive
at the speed that you'replanning for. So some
curvature, but not real sharp.
No 90 degree turns, things likethat. Yeah . If you're just
designing a road from scratchlike that.

Bernie Fette (03:47):
Alright . Then with those considerations in
mind, can you walk us throughthe steps of how speed limits
are determined?

Marcus Brewer (03:54):
Sure. And it's, that's a great question. Within
Texas to start with, there'ssome legal basis for that. The
Texas Transportation Code, thestate law essentially provides
that initial framework for howspeed limits are determined.
And there are some maximumnumbers, some specific speed
limit numbers based on certaintypes of roads and driving

(04:16):
environments, particularly ifthey're located in an urban
area or a street. If it's analley or some kind of special
access road, then that's even alower speed limit. If it's a
freeway or a numbered highway,then of course those numbers
are higher to start with. Andthose are kind of the starting
points based on state law. Butthen there's exceptions after

(04:38):
that to determine what is mostappropriate for that. And how
we get into that is a studymethod that determines what
either is anticipated for aroad that's not built yet, or
for a road that exists, if aspeed limit change is explored,
what are the conditions on thatroad and are they suitable for
a change? And for a number ofstate and federal highways, et

(05:00):
cetera , TxDOT, the TexasDepartment of Transportation is
responsible for setting thosein Texas. For city streets,
then the municipaltransportation department is
responsible for that. Countyroads are managed by the
respective counties. And so thecity council would set an
ordinance in a city, countycommissioner court would
establish a minute order orsome sort of equivalent at the

(05:22):
county level. Okay.

Bernie Fette (05:24):
There's one aspect of the speed studies
that people in your line ofwork do that I was hoping you
could explain for us, that I'veheard over many years at TTI of
the 85th percentile. As Iinterpret that, and I really
want you to get into a boileddown version of this if you
would, but as I consider thatand asking you the question
that I asked earlier about whodecides what a speed limit is

(05:46):
gonna be to at least a limitedextent, people who are driving
on that road have a say throughtheir own actions of what that
speed limit's gonna be. Is thatfair?

Marcus Brewer (05:56):
Yeah, that's a good principle because that
rule of thumb of 85thpercentile essentially means
that the posted speed limit isa number in miles per hour of
what we estimate 85 percent ofthe drivers on that road are
going to be traveling at orbelow. So it is reflective of

(06:17):
the speeds that drivers aregoing for a road that's already
in use and something that canbe measured of the speeds that
people are traveling. And inTexas, the Texas Administrative
Code requires that speed limitsbe based on that as a starting
point. And it's a rule of thumbfor a wide variety of other
roads, both within Texas andelsewhere with historic

(06:38):
principle that many drivers arereasonable and prudent. They
desire to avoid a crash, theydesire to arrive at their
destination in a reasonableamount of time. And yet there
are always some number ofdrivers that are probably
outside of that range, and sothey're just gonna drive faster
or whatever the case may be,whatever adjective we might
wanna put on that. Okay.

(06:59):
Relative to everybody else. Andthat's why that number is 85
and not a hundred, for example.
Okay .

Bernie Fette (07:04):
Okay. And in some cases there are actually
minimum speeds along with themaximum limits, isn't that
right?

Marcus Brewer (07:11):
That's true.
That's typically for freeways.
And the idea is that becausethe maximum speed limit is at
the high level that it is, wewant to keep that speed
differential relatively low.
Because

Bernie Fette (07:27):
You mean the difference in the speeds that
cars are driving when you saythat "differential?"

Marcus Brewer (07:31):
Correct. So the fastest car versus the slowest
car, you want to keep that at aminimum because while we've
found that high speeds canaffect, say the severity of a
crash, so for example, ifyou're driving and you run into
a fence and you're going 10miles an hour, that's not all
that severe probably. But ifyou run into it at 70, that's a

(07:52):
different story. And the sameway when cars run into each
other, if they're going atvastly different speeds, the
chances of that collision goesup. And so that's a different
issue about crash severityversus crash frequency. So I
would say in terms of arelationship between speeds and

(08:13):
crashes, the severity can berelated to the speed, but the
frequency can be related to thedifferential. And if that's too
technical, we might be able toreword that . Yeah.

Bernie Fette (08:26):
Maybe, maybe we can get into that just a little
bit more in a minute, but Iwanted to stay on that minimum
for just a moment if we could,because I'm going from my own
memory over many years ofdriving on various streets and
interstate highways, it seemsthat I don't see minimum limits
posted as often as I used to.

(08:46):
Am I imagining that, or is it aless common practice than it
used to be?

Marcus Brewer (08:51):
Well, each state has its own characteristics of
course. Okay . And And notnecessarily every speed limit
sign on a freeway is gonna havethat minimum. A lot of times,
for example, you see more ofthose signs at a state line,
you're entering the state forthe first time and there's lots
of additional signs to tell youwhat state laws are. Right .
And those are not necessarilyrepeated everywhere. It doesn't
mean that the minimum doesn'tapply on the freeways, but it

(09:15):
may not be posted as often.
Okay. But definitely havingthat minimum speed on a freeway
is important to help kind ofkeep traffic moving generally
at the same speeds and helpsprevent other problems that
could be caused by fastvehicles and slower vehicles in
the same place at the sametime.

Bernie Fette (09:31):
Are there any conditions or circumstances
under which an establishedspeed limit can be changed?
Sure. When you tell us aboutthat, please see if you can
give us an example of.

Marcus Brewer (09:43):
Sure. There's examples of speed limits being
changed in a lot of conditions,a lot of circumstances where
individual roads are reviewed,usually at the request of
someone who lives nearby ordrives it often, or maybe the
road agency itself. But there'salso occasions where an entire
area or an entire set of roadsmight be reviewed as one unit.

(10:06):
So an example of a specificroad could be there is a
perceived or an actual changein how the roadway is
functioning, either becausethere's a lot more traffic on
the road than it used to be, ormaybe there's been some
crashes. Crash history or nearmisses. Correct. Exactly. Yeah
. And so the road agency willlook and say, our vehicles

(10:28):
traveling, first of all, thatspeed study that we mentioned
earlier, our vehicles reallytraveling near that posted
speed limit in the first place.
And if they're not, then that'sone factor, obviously. But
another is, let's say that theroad we talked about at the top
of the discussion that's 50miles an hour and there aren't
very many driveways on it.
Well, as the neighboring cityexpands and now there's more

(10:49):
driveways and there's moreintersections and more people
turning in and out, that causesmore potential for conflicts.
And so we may want to reducethe speed limit in that area
because there's more cars andthey're doing more things
entering and leaving theroadway to where a speed limit
of 50 isn't realistic anymore.
Or it may not be safe, or itmay not be the best

(11:11):
operationally. And so thosespeed limit studies are done to
determine should it be changed?
And if so, maybe what is thatnew number?

Bernie Fette (11:19):
And it sounds like what you were saying about
the addition of driveways as anexample, that could be the new
development that you mentioned,you know, commercial
development, more businessesout along that roadside or more
oil exploration, more energyexploration. Mm-Hmm .
so that you'vegot cars slowing down a lot for
those driveways. And those arejust conditions that change

(11:42):
Mm-Hmm . notbecause of any other reason
than the, the circumstances orthe conditions of that roadway
changed.

Marcus Brewer (11:48):
Correct. And it's not even necessarily the
roadway itself, it's everythingthat's kind of happening around
the road in the, in thesurrounding environment, the
roadside and the neighboringdevelopment.

Bernie Fette (11:58):
Yeah. Does public sentiment ever influence
decisions about speed limits?

Marcus Brewer (12:05):
It can. And the procedures that are on the
books, both within, say TexasState Code and, and within
municipalities and otheragencies really do talk about
following the procedures of thestudy and the protocols and so
forth to arrive at the numberbased on what the data tell us.
And that's the ideal solution.

(12:25):
That's the way that we try toproceed as a profession when
those happen. But yet we knowthat there's people that drive
on these roads and they haveperceptions and there's things
that they're involved in andthings that they observe that,
you know, may be difficult toquantify in a study.
And those perceptions may ormay not be the most accurate.
And that's why we'd have thestudy in place to help quantify

(12:46):
what we see. But yet it canhappen where whether it's a few
people that are influential orwhether it's just a lot of
people that have a particularissue with how a certain road
is posted , uh, in its speedlimit, they can bring that to
bear. And that can beinfluenced by that kind of
feedback from the public.

(13:06):
Ideally, that should still bebacked up by a study that says
the data reflects what thoserevised conditions are. And
part of the reason why that canhappen is because even if the
traffic engineers do theirstudy and make their
recommendations, ultimately thegovernmental agency is
responsible for making thatdecision. So if a city council
wants to set an ordinance tosay we're gonna change the

(13:29):
speed limit, it may be that thedata don't quite ideally line
up with that at the time. Maybeit's projected to in the
future, but because the issueis here, now we go ahead and
make that change because that'swhat's being brought to bear
on, on the people ultimatelyresponsible for deciding.

Bernie Fette (13:44):
Yeah. Interesting that you would mention the city
council because I remember mydays in city government years
before I came to work for TTI,it, it was not unusual for a
decision like you're talkingabout to be made based in part
on just how many citizensshowed up to the city council
meeting to argue their case.

(14:05):
Mm-Hmm.

Marcus Brewer (14:06):
.
And I think it's that way in alot of different areas of life,
but this is definitely oneexample where a lot of times
the people are satisfied withwhat's going on. You know,
people don't tend to show up atthe meetings to say, Hey, great
, keep doing what you're doing.
It's folks that have an issueor perceived problem and they
want to hear about it. Andunderstandably so then the

(14:26):
council members or whoever itis on that board listen to
those comments and that it canaffect their outlook on things.

Bernie Fette (14:33):
Yeah. If we could get back to the relationship
that we were talking aboutearlier between speed and
crashes. Mm-Hmm. , uh, I'm gonna toss out
something and ask you tocorrect me or maybe edit what
I'm saying. I'm trying tofollow what you were saying
earlier about the speeddifferentials. Okay . Is it
fair to say that higher speedsdon't necessarily contribute to

(14:56):
crash frequency, but they havea lot to do with crash
severity?

Marcus Brewer (15:01):
Yeah, I think so. Let's talk about, I guess
kind of those two concepts ofcrash . Yeah . Your turn . So
maybe I can clarify ,maybe I can clarify what I ,
what I referred to. So there'scrash frequency, which is how
often do crashes occur? Andthat's a lot of times the
numbers that we look at crashesper month or per year or
whatever metric that we'reusing to, to count that number.

(15:22):
And then we have crashseverity, which is, you know,
did we just have a fenderbender or were people injured?
And if they were injured, howseverely were they injured?
What was the extent of thoseinjuries? What we found on
crash frequency is that instudies that have been done in
Texas and elsewhere, theresults are mixed. So yeah,
there's not a clearrelationship between just a

(15:44):
speed and the frequency ofcrashes. You can't just say,
the faster we go, the morecrashes we're gonna have.
That's not borne out by thestudies that have been done.
But what we do find is thathigher crashes do tend to lead
to more severity because higherspeeds the faster you go. Yes.
Higher speeds, the faster yougo when you hit something

(16:06):
, chances are it'sgonna cause more damage to your
vehicle and to yourself. Butwhat we then do find about
crash frequency is that speeddifferential. So the difference
in speed between the twovehicles that collide makes a
difference. You can havecrashes between two vehicles
going at relative close to thesame speed and you can kind of

(16:28):
get your fender bender ,especially both of those
vehicles are kind of slowanyway. But in the case of the
freeway where if you've gotsomeone traveling, we'll say 70
miles per hour and they'recoming up on a vehicle that's
only traveling 45, they rearend that vehicle, that's gonna
be a pretty substantial event.

(16:49):
So those types of things dofactor in, which is one reason
why I'll put in a small plugfor roundabouts, because I like
to do that. Roundabouts slowpeople down at intersections.
And so it eliminates theopportunity for what we call
those T-bone crashes. And thoseare high speeds because
everyone has to slow down at aroundabout. And so the crashes

(17:09):
that do occur tend to be at,you know , say 15 miles an
hour. And they tend to be atangles that are fairly similar
rather than people approachingat right angles and going 35,
40, 45 miles an hour. And sothose crashes at roundabouts
are much more survivable,injuries are fairly low and
even so are the damages to thevehicles.

Bernie Fette (17:29):
And if we look back, staying on this part of
the discussion for just anotherminute, if we look back at the
COVID-19 experience, we had farfewer people out on the road
due to the fact that we werehaving remote work, fewer
shopping trips, et cetera.
Mm-Hmm. , lots ofus expected fewer people on the
road to translate to fewercrashes. But that didn't

(17:52):
happen. There was actually anincrease in crashes, many of
them pretty severe. That wasapparently attributed largely
to speeding. Can you elaborateon that instance a little?

Marcus Brewer (18:05):
Sure. And what I'm gonna say with this is
gonna be a mixture of boththings we've studied and
probably just some personal andanecdotal observation, but ...

Bernie Fette (18:14):
That's fair.

Marcus Brewer (18:14):
As the amount of traffic went down, people
stayed home for whateverreason, either the motivation
or the requirement to be offthe road, that opened up the
roads for everybody else whotraveled them. And so , you
know, in the past where let'ssay you're driving to work at
7:45 in the morning and so area lot of other people, and all
of a sudden a lot of thattraffic is gone and that

(18:36):
happened throughout the day.
You can pick a different timeof day where if most people are
staying at home, that opens upthe road. And so you have a
sense for a driver that'straveling during that time that
hey, this is kind of my roadand I can be a little more
flexible in what I wanna do.
And probably the perceivedthreat of enforcement might be

(18:58):
a little lower, whether that'sreality or not. And all those
things kind of contributed tothen a factor of, hey, I've got
somewhere to be and I'm out onthe road by myself. I'm just
gonna drive fast or as fast asI kind of want to. But then you
do get into that situationwhere when you do drive faster,
this is where some of thosestudies that we talked about
earlier kind of differ onfrequency of crashes. There is

(19:20):
definitely an influence on ifyou're driving faster, you have
less time to react to somethingthat's on the road, you have
less ability to respond tothings, especially if you're
distracted in that car again,if you think you're on the road
by yourself, so I'm gonna be onmy phone while I'm driving
other things that can be atplay. Yeah, those have an
effect. And so then the speedkind of exacerbates that

(19:44):
situation. And especially againfor the injuries because then
as people go faster and theyrun off the road and they hit
something or they hit anothercar, then that makes a
difference. And so people kindof get used to that, having the
road to myself and then theysee another car or something
else can cause a crash. Andthat does lead to an increase
in crashes.

Bernie Fette (20:03):
So since you were talking about personal
observations, I'll make onemyself, it sounds like some of
the people that we were talkingabout may have had a inflated
sense of their driving skills.

Marcus Brewer (20:14):
Anecdotally, yes. .

Bernie Fette (20:16):
Okay. But fair enough. A anecdotally, yes. I
know you're a scientist, I'mnot gonna try and push you too
far in that direction. You and your colleagues have
been studying speed limits fora lot of years. I'm wondering
what might be the next thing onyour research agenda. If a
sponsor, whether it's TxDOT orFederal Highway Administration

(20:37):
or somebody else, and hands youa big blank check and you could
study whatever you thought wasimportant and you weren't gonna
be influenced on the conduct ofthat research by the people who
were funding it, you get todecide what's important. What
are you gonna study?

Marcus Brewer (20:54):
Well , that's a great question and I definitely
like the concept of a blankcheck. I think some of that's
gonna relate to what we werejust talking about, about why
do people choose the speed thatthey drive. The roadway design
is obviously a factor in that.
So if you have a freeway, it'sgonna have wide lanes, it's
gonna have wide shoulders,there's not gonna be any

(21:17):
driveways on it. The curvatureis, is nice and easy. There's
lots of things that promote ahigher speed. And so the design
of that roadway lends itself todrivers selecting a higher
speed. In the urban areas,you've got narrow lanes, you've
got on street parking, you'vegot sidewalks, you've got
perhaps frequent trafficsignals and driveways and

(21:37):
things that slow people down.
And people are kind of used tothat kind . Where we're looking
at in the profession right nowis kind of that place in the
middle of say that 50 or maybea 40 mile per hour type of road
that we've talked about beforethat maybe it started out as
one thing and it's changed tosomething else over time. Or as

(21:59):
we look at a roadway that mayhave been suitable for the
conditions at the time. And asthings change , how can we
either design the roadway ormaybe influence the roadway
environment near it to helpencourage people to pick a
speed that's appropriate. Andthere's a lot of factors that
go into that that aren't evennecessarily within the purview

(22:22):
of the roadway designer. Imean, there's certain things
that the designer can do tosay, we have X number of lanes
and we have a shoulder, we havea curb, or we have a median, or
whatever those things might be.
And we have guidelines thatdirect those decisions and
those are being reviewed. Buteven so, if we have to your
hypothetical driver a momentago that may or may not have an

(22:45):
accurate sense of that driver'sability, what is it that
motivates that driver to selectthe speed that the vehicle
ultimately travels? Andespecially within Texas, as we
do have higher speed limitsthan most other states and 75
mile per hour on even thingsthat aren't freeway, they kinda
look freeway, but they are notcompletely free of driveways

(23:08):
and intersections. And even onrural two lane roads that may
have a lot of driveways, , but yet we see
people applying freeway speedsto non-free roadways because
they get comfortable drivingthe speeds that are consistent
with those freeways. And so I,that gets into the psychology
and human factors and there's alot of other things that aren't

(23:31):
directly related to theroadway, but I think it gives
us some insight into thatspeed. But then the resulting
operation of the road andobviously the safety of the
road and are we building roadsand roadway environments that
are consistent with how peopleare using them? And right now
we actually do have an ongoingproject with National

(23:51):
Cooperative Highway ResearchProgram, the N-C-H-R-P-A
federally funded program thatis looking at the concept of
target speed. And it really isright now emphasizing this kind
of middle ground of say 30 to50, 30 to 40 range of posted
speed limits to say what shouldour target be? And and that

(24:12):
concept is even developing onwhat target speed means. But
the idea is that if I'mdesigning a road, how fast do I
think people should betraveling on it? And that's my
target. And it's related to howthe roadway is designed because
we want to design a roadwaythat's consistent with how fast
we think people should be usingit, but how can we pull in some

(24:36):
of those other things thataren't specifically number and
width of lanes? You know , howcan we pull in some of those
other things into the overalldesign process about planning
and roadside environment anddevelopment. And I think if we
had a blank check, those aresome concepts, some areas that
we would really like to diginto further to say what's

(24:58):
going on in the driver's head,what is the performance of the
vehicle they're driving andwhat's going on in the roadside
environment that helps tocontribute to that driver's
choice to decide, I'm gonnapick 50 or 55 or 70 or 30 on a
road that may have a number ona sign that's different from
whatever that is that theychose. And it's some

(25:20):
fascinating stuff and there's alot of people in the industry,
not just at TTI, but elsewherein the profession that are
looking at that. And that kindof seems to be where we're
headed and it's reallyinteresting stuff that people
want to know more about.

Bernie Fette (25:32):
Definitely.
Sounds like you've got some jobsecurity there.

Marcus Brewer (25:35):
There's no shortage of people speeding,
let me put it that way.
.

Bernie Fette (25:39):
Okay. Anything you'd like to add that I
haven't asked you about?

Marcus Brewer (25:42):
Couple of things. One, you mentioned
colleagues and they , some ofthe things that I've been
talking about actually havebeen developed by others at TTI
for TxDOT-sponsored projects.
They've put together somediscussion on how speed limits
are set and and how they go.
And Kay Fitzpatrick led thatproject among a number of other
speed limit related items. MikePratt and Steve Venglar were

(26:04):
part of that. And so Iacknowledged their
contributions and putting someof that material together more
recently and they provided someresources that are out there
for that. But also just, Iwould just say for the average
driver, the person that's notnecessarily in the
transportation research realm,as you're driving down the
road, think about what it isthat motivates you to choose a

(26:26):
speed. Some of it is, you know,I have a deadline to be
somewhere and so I need to getthere in a certain amount of
time. And that's obviously afactor. But as we're driving
somewhere, if I'm in town, am Ilooking for other vehicles? Am
I looking for pedestrians orcyclists? Am I anticipating
where that that next trafficsignal or roundabout is? Um, if
I'm out on the highway outsideof town, am I just putting the

(26:49):
gas pedal down and going, or amI thinking about what's gonna
come up maybe around the nextcurve , over the next hill? And
why do I drive as fast as Idrive? And it'd interesting to
know kind of what people thinkabout that and maybe that helps
motivate some people's drivingdecisions as they're going
along about their daily lives.

Bernie Fette (27:09):
You mentioned what motivates driver
decisions. So speaking ofmotivations, what is it that
motivates you to show up towork every day?

Marcus Brewer (27:20):
That's a great question. I wanna be able to
provide resources, information,et cetera, that help us be able
to allow the public to get fromplace to place more safely,
more efficiently, and hopefullyeven enjoy where they're going.
And so if I'm able to do thingsin my work that give us a

(27:43):
better transportation system sopeople can get from place to
place and we can get things inthe stores better and we can
visit family and friends andenjoy things that we need to do
and do it safely andefficiently, then I think I'm
doing my job.

Bernie Fette (28:00):
We've been visiting with Marcus Brewer, a
research engineer at TTI.
Thanks so much for joining us,Marcus, and helping us
understand at least some of themysteries behind speed limits.
We really appreciate it.

Marcus Brewer (28:13):
My pleasure.
Thanks for the invitation.

Bernie Fette (28:17):
That road you travel most days -- the one
that takes you to work, toschool, to your favorite
restaurant or shopping center-- what does that road look
like? Four lanes or more?
Traffic lights? Lots ofbusinesses and driveways, or
maybe just a few? All of thosethings are factored into

(28:37):
deciding what that road's speedlimit is going to be. Oh, and
there's one more, thereasonable and prudent behavior
of the people who use thatroad. So the next time you're
driving along and wondering"who are the people who decided
that this was going to be a 40mile an hour road." Just

(28:58):
remember -- it's possible thatyou are one of those people.
Thanks for listening. Pleasetake just a minute to give us a
review, subscribe and sharethis episode, and please join
us next time for anotherconversation about getting
ourselves and the stuff we needfrom point A to point B.
Thinking Transportation is aproduction of the Texas A&M

(29:21):
Transportation Institute, amember of the Texas A&M
University System. The show isedited and produced by Chris
Pourteau. I'm your host, BernieFette. Thanks again for joining
us. We'll see you next time.