last updated December 31, 2015
is a big
place. It's nearly 880 miles from the Louisiana border near
Orange to the New Mexico border near El Paso, and nearly 500 miles from
the Oklahoma border north of Dallas to the Mexican border in
Laredo. That size gives the state a tremendous amount of
diversity. A hot, humid sub-tropical climate in the Valley
to a varying Midwest climate, complete with snow, in
There are Piney Woods in East Texas, desert in West Texas, and plains,
prairies, and the Hill Country in between. The state has some
the nation's biggest metropolitan areas and some of its most desolate
ranges. With this size and diversity, a large and rapidly
population, a booming economy, an increasing role in international
trade, and its overwhelming dependence on the automobile, Texas cannot
help but have the nation's biggest, most well-developed highway system
with nearly 80,000 miles of state-maintained roads.
designed to give you an overview of the state's highway system and its
idiosyncrasies. If you're looking for a route log, check out
Routes by David Stanek, a complete listing of all
Texas. Both Ron Jackson's TexasFreeway.com
Andy Field's LoneStarRoads
lots of in-depth information on freeways and other highways statewide.
On this page:
Texas highway facts
are managed by the Texas Department of Transportation
TxDOT was created in 1991 from the former State Department of Highways
and Public Transportation (SDHPT). Here are some facts about
highway system in Texas:
|TOTAL LANE MILES
HIGHWAY: Started in 1918 and finished in 1920, between
and Encino in Brooks County, along present day US 281.
INTERSTATE: 1956, I-45 (then US 75) near Corsicana in Navarro
HIGHWAY: Loop 168 in Tenaha, Shelby County, is 391 feet (.074
HIGHWAY: US 83 stretches 899 miles from the Oklahoma state
near Perryton to the Mexican border near Brownsville
HIGHWAY: A spur from Texas 118 at the McDonald Observatory on
Locke in West Texas is 6,791 feet above sea level.
HIGHWAY: I-10/Katy Freeway in Houston just west of Beltway 8
carries 328,000 vehicles daily.
BRIDGE: The Queen Isabella Causeway between Port Isabel and
Padre Island is 2.37 miles long.
highways comprise about 26% of the total roadway mileage in Texas but
carry about 73% of all traffic.
having the nation's largest highway system overall, Texas also has more
Interstate mileage than any other state. There are now 17
Interstates in the state:
has two of the three "forked" Interstates in the nation.
The first, I-35, is split into I-35E
through Dallas and I-35W through Ft. Worth. I-69 is split
three ways: first, I-69 splits into I-69E and I69W at Victoria with
I-69E running south to Brownsville along US 77 and I-69W continuing
south to Laredo along US 59. Then
I-69C branches from I-69W at George West and runs along US 281 south to
I-2 at Pharr
also has two "hidden" or unsigned Interstates: I-345, which is
a short extension of I-45 in downtown
Dallas, and I-110, which connects I-10 to the
Mexico border in El Paso.
Texas were generally developed along existing US and State
highways. I-45 replaced US 75, I-35 replaced US 81, and I-40
replaced the famed US 66, to name a few. In urban areas, many
existing expressways were simply re-signed as Interstates.
first Interstate contract let in Texas was for a segment of I-45 in
Navarro County near Corsicana in 1956. The latest
to Texas' Interstate inventory is I-69. (See the I-69 section
below.) Prior to that, the
last Interstate to be completed was I-27 between Lubbock and Amarillo
inter-urban Interstates in Texas, I-35 between San Antonio and
Dallas-Ft. Worth is the busiest. Most of I-35 operates at or
above its capacity. Every traffic counter location between
Antonio and Hillsboro reported more than 50,000 vehicles per day in
2008. As a result, traffic delays, especially during holiday
periods, are common. Besides increases in passenger vehicles,
truck traffic on I-35 and other Interstates is growing rapidly, mainly
as a result of the North American Free Trade Agreement (NAFTA) and the
General Agreement on Tariffs and Trade (GATT). TxDOT reports
Interstate traffic has increased every year since 1987.
1996 and 1999, passenger vehicle traffic statewide increased 12% while
truck traffic increased 19%, and between 1999 and 2011 truck traffic is
predicted to grow 50-70%. In fact, Texas has the highest
of truck traffic in the nation.
between San Antonio and Georgetown is now six lanes or more, and a
bypass tollway (SH 130) from Georgetown to I-10 at Seguin was completed
in 2012. Work continues to upgrade I-35 to six lanes all the
north to Hillsboro. TxDOT is also participating a $1.5
federal study of I-35 from Laredo to Duluth, Minnesota, which aims to
provide comprehensive improvements to the corridor. (More
information on the I-35 corridor between San Antonio and Austin is
available as part my San
Antonio roads pages.)
addition to I-35, TxDOT has plans to widen the other two legs of the
"Texas Triangle" (I-10 between Houston and San Antonio and I-45 between
Houston and Dallas) to six lanes.
Exits, entrances, and the
ubiquitous frontage roads
As you drive through Texas, you may notice that exits and entrances on
many of our Interstates tend to be at more frequent intervals than in
states. This is the result of the wishes of Dewitt Greer, a
former long-time director of the state highway department. It
his belief that, given the vastness of the state, Interstates should
not just serve "interstate" traffic, but also "interregional" traffic
within Texas, and more frequent exits would help facilitate that.
byproduct of this philosophy is perhaps the most unique feature of the
state's highway system: frontage roads. There are over 7,000
miles of these along freeways in Texas, which is more-- much more--
other state. The reason for the widespread use of frontage
in Texas again can be traced to Dewitt Greer. He decided that
was cheaper to build frontage roads to keep access to adjacent
properties than it was to purchase those access rights, which is
required under state law. This quickly became standard
procedure at the Highway Department (and subsequently TxDOT) and nearly
all of the state's freeways were built under this policy. In
2001, the Texas Transportation Commission considered a major policy
change that would've rocked TxDOT and Texans in general to the core--
frontage roads would not be included in any new freeways unless
absolutely necessary. This was a fundamental change and
quite a stir around the state-- enough of one that the Commission
decided, after statewide hearings, to scrap the idea.
several ramp configurations used with frontage roads. The
"diamond" interchange is pretty standard, with the on- and off-ramps
connecting to the frontage roads in the general shape of a diamond
relative to the cross street (see illustration below).
especially in urban areas, the ramps are reversed in an "X"-interchange
with the exit ramp for the next cross street preceding the entrance
ramp from the previous cross street. This provides better
to and from frontage properties between the intersecting roads and
through traffic loads on the frontage roads at intersections.
Occasionally, if space is limited, both the on and off ramps
built at the same location in a "braided" arrangement (i.e. one ramp
passes-over the other).
roads with diamond interchanges
roads with "X" interchanges
frontage roads generally range from 50-60 mph in rural areas to 40-50
mph in urban areas. In urban areas, access roads are one-way
the same direction as the adjacent freeway lanes. In rural
they are generally two-way. On the frontage road, traffic
or entering the freeway has the right-of-way.
frontage roads are an oddity unique to Texas. However, within
Texas, frontage roads have their own oddity. If you travel
through the state, you may notice that people in each of the major
cities call their frontage roads something different: in Houston,
they're "feeder" roads; in Dallas-Ft. Worth, they're "service"
roads; in San Antonio, they're "access" roads; and in El Paso,
they're called "gateways". The term generally used
and the state's official term is "frontage" road, which is how you'll
see them marked on guide signs statewide, even in the aforementioned
areas where the popular vernacular differs. You can often
what part of the state someone hails from just by asking them what they
call that road next to the freeway.
noted that frontage roads (or whatever you call them) are not just
found on Interstates-- US and state
highways that are freeways also commonly have frontage roads.
frequently surprised when they go to other places and find no frontage
roads. A comment many make after their trip to another
state is, "They don't
have frontage roads on their highways!" But many native
realize how much of an oddity our extensive frontage roads
Conversely, many out-of-state visitors immediately notice and comment
on our frontage roads with no clear majority between thumbs-up
hand-in-hand with frontage roads are
"turnarounds". These are separate U-turn ramps that allow
heading in one direction on a one-way frontage road to turn
and head the other way on the opposite frontage road without having to
traverse the two frontage road/cross street intersections (see diagram
below). This helps ease congestion in those
Turnarounds can run underneath the freeway using the same underpass as
the cross street, or they can cross over the freeway on the same
overpass as the intersecting street or on separate
overpasses. Turnarounds are only used on
frontage roads and therefore are generally found only in urban
areas. Like frontage roads, these may have different names in
different parts of the state. "Turnaround" is the term in San
Antonio, and it's the only place that actually uses "Turnaround" signs,
although the "U-turn ONLY" sign found in most of the rest of the state
is starting to make an appearance there. Other terms used for
turnarounds are "U-turn lane" and "crossover", although the later more
correctly describes an opening in the median on a divided highway.
turnaround in San Antonio
Another semantic idiosyncrasy is how TxDOT abbreviates
"Interstate". In most other states, it's I-35, I-10,
Here, TxDOT's official term is "IH", as in IH-35 or IH-10, with "IH"
being short for "Interstate Highway". Furthermore,
depending which part of the state you're in, you may locals using that
term as well. (As you can tell by my pages,
I prefer "I" myself.) I believe TxDOT uses "IH" because all
their other highway abbreviations are two letters as well.
Interstate 69 and Interstate 2
growth of NAFTA traffic, Texas began making plans in the late '90s
for a new Interstate, I-69, from Texarkana through Houston and on to
Laredo and the lower Rio Grande Valley. During
the first decade of this century, planning for this
route was rolled-into the Trans-Texas Corridor as "TTC-69" (more
details on the TTC below)
I-69" signs began appearing on US 59 in the Houston area in
after the demise of the TTC, the I-69 project was continued as a
will upgrade the existing US 59 corridor, one of several corridors
strained by burgeoning NAFTA traffic. South of
Victoria, I-69 forks into two routes: I-69E along US 77 south to
Brownsville and I-69W, which continues south along US 59 to Laredo.
Near George West, another spur, numbered I-69C, branches off
of I-69W and follows US 281 south to Pharr.
the Federal Highway Administration approved Texas' request to sign the
first section of I-69 in the state. In December 2011, signs
up on a 6.2 mile section of the US 77 expressway between I-37 and
Robstown just west of Corpus Christi. In September 2012, 35
of US 59 stretching from Loop 610 in northeast Houston to the
Montgomery/Liberty county line was also signed as
I-69. Since then, numerous additional sections have been
signed as they have been upgraded to Interstate standards and, as of
May 2015, there were 194 miles of I-69 signed in Texas.
part of the I-69 project, the federal government approved signing US 83
through the Rio Grande Valley as I-2, connecting I-69C at Pharr with
I-69E at Harlingen.
information on I-69 in Texas is available at the Alliance for I-69
In December 2015, the US Congress passed legislation that approved the
designation of another new Interstate in Texas, I-14. Nicknamed the "Forts-to-Ports" route, this
route was proposed
by the Gulf Coast Strategic Highway Coalition and is intended to
provide a high-speed east-west corridor through the middle of the state
connecting Ft. Bliss, Ft. Hood, and Ft. Polk in Louisiana and connectivity via
other existing highways to the military ports in Beaumont
and Corpus Christi. I-14 is planned to subsume most of the current
route of US 190 from West
Texas to the Louisiana border east of Jasper, connecting Brady,
Killeen, Belton, Bryan, Huntsville, and Livingston. Some portions
of the route have not yet been finalized including the section from
Bryan to Huntsville and the routing west of Brady. While the
official designation currently calls for I-14 to join with I-10 in West Texas,
planners are looking at possibly routing it northwest from Brady
through San Angelo to Midland/Odessa. As with I-69, it is
possible that both legs may eventually be built. Also like I-69,
I-14 would be built piecemeal by designating existing freeways in the
corridor as I-14 in the near-term (such as the stretch of US 190 in the
Killeen area) and then upgrading portions of the rest of the corridor
to freeway standards as funding becomes available. The first
sections of I-14 could be signed as early as 2017.
information on I-14 is available at the Gulf Coast Strategic Highway Coalition
Interstate 27 extension
TxDOT commissioned a study during the early '90s to investigate
extending I-27 south from Lubbock. Three corridors were
considered: US 87/SH 349 to Midland, a Sweetwater-San Angelo-Junction
corridor connecting to I-10, and another corridor through Big Spring to
I-10 at Ozona with the I-20 to I-10 segments of these
corridors studied separately from the Lubbock to I-20
corridors. The study concluded that there was not enough
traffic, present or projected, to warrant an extension of I-27 for the
foreseeable future. Instead, a package of
upgrades to US 385, SH 349, US 87, and US 84 was recommended.
passage of NAFTA, additional studies have been done on this
"Ports-to-Plains" corridor. You can read more about it at
website and at the Ports-to-Plains
website. Once again, projected traffic volumes were
not be sufficient for an Interstate in this corridor.
various options including bypasses, intersection improvements,
additional lanes on existing roads, and ITS measures were recommended.
Texas, like most states, switched from a sequential exit numbering
system to a milepost numbering system in the mid to late '70s and early
'80s. The exit number was typically posted on a tab above the
exit board, but starting in 2012, signs with the exit number
incorporated in the exit sign became the standard and began
Highway system includes State Highways (SH), Loops (LP), and Spurs
(SP). There are also Park Roads and Business
are a few "special" state highway designations as well: OSR (Old San
Antonio Road) near Bryan, NASA Road 1 leading to the Johnson Space
Center, and Beltway 8 around Houston.
A term you are sure to hear across the state is
Even when they're Interstates, you'll usually hear beltways and other
bypasses referred to as "Loop" such-and-such. For
I-410 around San Antonio is usually called "Loop 410" and I-610 in
Houston is known simply as "The Loop" (usually with the cardinal
inserted, e.g. "the West Loop.") However, there is an
state highway designation of "Loop (LP)". This category
many routes that are not circular or even a bypass! Short
highways whose main purpose is to connect two or more highways are
usually designated as a Loop. A good example is Loop 1 (MoPac
Expressway) in Austin: it is basically straight and runs pretty
much through the heart of the city, but it connects several US, SH, and
FM routes along the way.
to 1991, all business routes
carried an internal or "hidden" arbitrary State Highway Spur or Loop
although in most cases they were actually marked with the business
route sign for the parent route from which they branched. In
1991, those internal designations were dropped and the business route
designations were made official.
business routes is unique. Firstly, TxDOT often puts a small
letter at the bottom of most business route shields (see example to the
right.) This letter
indicates which branch in the series for the parent highway that
particular segment is. For example, US 90 passes through
towns. The business route through the first town would be
"A", the one through the next town labeled "B", and so on, although
this practice isn't followed consistently throughout the
Secondly, on US business routes, TxDOT often does not use the "BUS" or
"BUSINESS" auxiliary plate mounted above the US route marker.
Rather, the word "BUSINESS" is included within the US shield above the
number, as shown to the right.
Business Loops were fairly rare in Texas until the state decommissioned
all US highways that were completely coexistent with Interstates in
1991. Along those Interstates, the US route had previously
provided the parent route for the business routes. Those have
since been replaced with Interstate Business Loops.
The state also has 88 or so Park Roads and
which provide access to state and national parks and other designated
recreational areas. TxDOT also maintains all roads within
parks, although most are not marked state routes.
More than half of the
state's highway system is comprised of the Farm-to-Market (FM) road
system, which also includes Ranch-to-Market (RM) roads.
the first FM road opened in 1937, the system really grew after the 1949
Legislature set aside $15 million annually from the state's General
Fund for their construction. General Fund money is no longer
used, but the FM system is still paid for entirely by the
The FM system is the most extensively developed rural highway system in
the nation. Its nearly 41,000 miles is more than double the
entire state highway mileage of the six New England states combined.
FM/RM route sign reads "Farm Road" or "Ranch Road", the routes are
officially designated as "Farm-to-market" or
Larger guide signs do mark the routes as "FM" and "RM" (see the
"signs" topic below.)
There is only one
route officially designated as "Ranch Road", that being Ranch Road 1
leading up to the LBJ Ranch east of Fredericksburg. There is
difference between FM and RM roads; just another Texas highway semantic
idiosyncrasy. Routes east of US 281 are generally labeled as
roads; those west of US 281 are generally marked as RM roads.
explosive growth of metropolitan areas
in Texas over the years, many FM routes are now in metropolitan
areas. Houston and San Antonio in particular have a large
of FM roads within their urban areas. One could drive many of
these routes and never see a farm or ranch, much less anything being
transported to market. Still, only about 4% of the total FM
mileage is within urban areas. Since the FM system is
state-funded, an effort was made in 1995 to create a new classification
for FM routes in urban areas called "Urban Roads" to enable them to
receive federal funding. The proposed sign would be the
state highway square with the word "urban" and the route
An outcry from the public about the changing the familiar Texas-shaped
sign stopped the plan to re-sign the roads, but TxDOT's internal
highway designation logs were changed to re-classify FM roads
metro areas as Urban Roads. In 2012, there were 252 roadway
segments classified as UR.
Urban Road system, TxDOT created a classification of roadway in 1988
called the Principle Arterial Street System, or PASS (designated as PA
routes.) This classification allowed for existing and new
urban arterials that provide access to or relief for major
state corridors (typically freeways) to receive matching state
federal funding without being officially signed as state roadways.
Due to financial constraints, the PASS program was
essentially discontinued in 1992 and is slowly being sunsetted with the
190 roadway segments included in the PASS system being funded as
resources become available or transitioned to other funding
always been on the leading edge of highway technology. The
Transportation Institute (TTI) at Texas A&M University has
spearheaded much of this highway research. Here are some of
many innovations to come from Texas:
Twist" guardrail end was developed in the 1970s to deflect vehicles by
burying the ends of the guardrails. As cars got smaller,
many overturned when hitting this. So in the late '80s and
'90s, TTI developed a new guardrail end treatment called the
ET2000. This new guardrail end absorbs the impact of a
extruding the rail and breaking the wooden posts.
initiated the concept of roadside parks. The first picnic
opened in 1933 along Texas 71 between Smithville and La
In recent years, though, funding issues, as well as the proliferation
of fast-food restaurants, has resulted in Texas closing an increasing
number of picnic and rest areas, especially near urban areas.
"adopt-a-highway" project was developed in Texas and it was the first
state to implement it statewide. More than 45 other states
since emulated this program. There are currently about 3,800
groups collecting litter along 8,000 miles of highway. It is
estimated that this program saves the state $2.5 million a year in
litter clean-up costs. (Also see the "Don't Mess With Texas"
posts and streetlights were developed in a two-year program in the
1970s to reduce
the seriousness of roadside object impact accidents. After
125 crashes resulted in not one single injury, the federal government
mandated their use on all federally-funded roads. Texas
also developed the breakaway "coat hanger" rural mailbox
which was recently redesigned.
version of the standard Jersey-barrier designed to reduce the
likelihood of smaller vehicles flipping over on impact was developed in
the 1980s by TTI. TTI also designed a special heavy-duty
extra-tall guardrail for a downtown San Antonio freeway ramp to prevent
heavy trucks from crashing down onto a high school football
field below the ramp. To test it, they crashed a fully-loaded
tanker truck into
it! This rail design has since been used in many other
where extra strength crash-barriers are needed.
Mess With Texas™
'80s, the forerunner of TxDOT introduced what would become an
incredibly popular anti-litter campaign: "Don't Mess With Texas".
Signs went up around the state and the slogan took off.
can get "Don't Mess With Texas" T-shirts, mugs, stickers, keychains,
hats... you get the idea. There have also been numerous
Mess With Texas" commercials featuring various celebrities.
TxDOT owns the trademark on the slogan and logo and zealously pursues
many areas reaching their maximum width, the Texas Transportation
Commission in 1989 committed to building Intelligent Transportation
Systems (ITS) in the state's largest metro areas. The first
system to go online was TransGuide in San Antonio, which at the time
was the first advanced metro freeway ITS system in the
TransStar in Houston followed shortly thereafter. Most of the
state's largest metro areas now have ITS systems, and it has been
expanded to several busy rural corridors as well. These
use a various technologies to monitor traffic conditions and warn
drivers of incidents and congestion. ITS also plays a major
role in hurricane evacuations and other emergency situations.
road signs than any other state. There are over 500,000 signs on state
the only state that has two different versions of our highway
markers. One version is the freestanding sign and the other
for use on freeway guide signs. Here are some examples:
|| GUIDE SIGN SHIELDS
World War II, the route marker for state highways was changed to
today's boring square. Prior to then, the shield featured the much more
unique circle and five-point star design shown at the left.
early 2000s, Texas law prevented the state from
building or operating toll highways. Instead, they could be
and operated by subsidiaries of TxDOT or independent agencies created
specifically for that purpose. For instance, the Texas
Authority built and operated tollways in the Dallas area, including the
Dallas-Ft. Worth Turnpike, which was the state's first toll
North Texas tollways are now operated by North Texas Tollway Authority
while the Harris County Toll Authority built and operates several
tollways in the Houston area (see sidebar below). In the late
'90s, a private toll road, the Camino Columbia, was built to connect
the Columbia Solidarity Bridge northwest of Laredo to I-35.
to a lack of traffic caused by federal delays to implementing the North
American Free Trade Agreement (NAFTA), that road eventually was sold to
the state and is now operated by TxDOT. In the early 2000s,
worsening congestion and declining revenue from the state gas tax, the
state promoted toll roads as a major mechanism to fund new or
expanded roads. To facilitate this, the legislature
authorized the creation of so-called Regional Mobility Authorities
around the state. Perhaps the most controversial
toll road proposal was the statewide Trans-Texas Corridor project (see below).
roads in Texas are marked with special signage such as that shown to
the right above.
|| The Sam
Houston Tollway around Houston is also signed as
Beltway 8, a state highway. However, because of the previous
restriction of not allowing state highways to be toll roads, only the
frontage roads along the toll route are actually Beltway 8.
tolled mainlanes are just the "Sam Houston Tollway", operated by the
Harris County Toll Road Authority.
In 2002, Texas Governor
Rick Perry announced a concept for a massive new transportation system
in Texas. The plan, called the "Trans-Texas Corridor" (TTC),
subsequently approved by the legislature and called for 4,000 miles of
superhighway/rail/utility corridors crisscrossing the state.
envisioned, each corridor would have been 1,200 feet wide and included
separate roadways for passenger vehicles and trucks, separate tracks
for freight and passenger rail, and a right-of-way for utilities such
as gas, oil, and water pipelines and electrical transmission and
telecommunications lines. Specifically, here's how a typical
corridor would have been divvied up:
lanes, four each way (A on the diagram below)
vehicle lanes, three each way (B)
tracks for high-speed passenger rail, with stations (C)
tracks for freight rail (D)
tracks for commuter rail, with stations (E)
corridor about 200 feet wide (F)
safety, and expansion zones as necessary
Corridor typical cross-section
(Letters correspond to descriptions above)
roadways would have had limited interchanges with exits only at
intersections with other TTC routes, Interstates, US highways, and
highways. It was planned that the passenger roadways would
have speed limits of 80mph. The corridors would have been
developed and operated by private companies under a state
franchise. These companies would charge tolls and fees for
were four priority corridors:
parallel or overlap I-35 from Denison to Laredo
I-69, from Texarkana to Laredo via Houston, with branches to the Lower
Rio Grande Valley
Dallas to Houston
Paso to Orange
project, however, met with fierce opposition across the state.
Opposition was especially pronounced in rural areas
as the wide corridors would have taken many acres of farming and ranch
lands. Furthermore, there was a general discontent with the
concept of having the roads operated by private companies, especially
ones with foreign ties. As a result, the project was killed
the Legislature in 2009. The TTC-35 and TTC-69 projects,
were in advanced planning at the time, continued but not under the TTC
brand. The TTC-35 project was also eventually canceled.
However, the segment from Georgetown to Seguin,
which had originally been conceived as a traditional toll project, was
allowed to be
completed as a regional project and today is SH 130.
Planning for TTC-69 (the I-69
extension) continued as a traditional Interstate project (see I-69
proposed Trans-Texas Corridor
(Priority routes are in
is the only
state that does not have statutory speed limits for different types of
highways in the state system. Instead, a general limit of 70
applies on any rural numbered highway regardless of classification or
number of lanes and 60 mph on any other rural roadway. A 30
general limit applies in urban areas. These limits can be
or lowered based on an engineering study. Speed limits can be
raised to 75 mph on numbered highways and up to 85 mph on select
roadways. This means Texas is the only state that has 75 mph
speed limits on two-lane roads.
speed limits have been increased across most of the US in recent years,
Texas has lead the way. Today, Texas has an 80 mph speed
about 520 miles of I-10 and I-20 in west Texas. Several
in the Austin area also have an 80 mph speed limit, and SH 130 from SH
45 south of Austin to I-10 near Seguin has an 85 mph speed limit-- the
fastest in the United States.
to 2011, Texas posted separate speed limits for trucks and for
nighttime. The truck limits were usually 60 mph when the
speed limit was 65 mph or higher and 70 mph when the general speed
limit was 75 mph or higher. Nighttime speed limits were 65
when the daytime limit was 70 mph or higher with nighttime
for trucks generally 55 mph. All truck and nighttime speed
were repealed in 2011.
help reduce air pollution, Texas experimented with so-called
"environmental speed limits" in the Houston and Dallas-Ft. Worth areas
starting in 2000. This scheme lowered the speed limit by 5
roads with an existing 65 or 70 mph limit. In 2002, speed
in the Houston area were arbitrarily lowered to 55 mph regionwide, but
opposition, poor compliance, and a finding that the lowered limit did
not significantly improve air quality scuttled that plan within a
couple of years and speed limits returned to the original 5 mph
reduction scheme. However, the uproar caused
legislature in 2003 to ban any new environmental speed
Environmental speed limits in the DFW region were completely
repealed in 2015.
late 2014, TxDOT conducted a pilot project for variable speed limits at
three locations around the state. Variable speed limits are
that can be adjusted in real-time to address congestion, inclement
weather, construction, or other issues that could affect traffic
safety. The results of the program will be analyzed by the
legislature to determine if it should be approved for statewide
two ferry services. The longest is on SH 87 from northern
Galveston to Port Bolivar. Another short ferry connects Port
Aransas and Aransas Pass on SH 361. The Harris County Toll
Authority studied a possible bridge to replace the Galveston-Bolivar
ferry, but determined it to not be feasible. Harris County
operates the Lynchburg Ferry east of Houston near San Jacinto State
currently no tunnels on the state highway system. At one
TxDOT did operate a tunnel under the Houston Ship Channel on SH 146
between La Porte and Baytown. It was replaced in the early
by the impressive cable-stayed Hartman Bridge. There are, however,
three road tunnels in Texas that are not part of the state highway
system: the Washburn Tunnel, which is also under the Houston Ship
Channel on Federal Road; the Addison Airport Toll Tunnel in Addison
north of Dallas (operated by NTTA); and one in Big Bend National Park.
sites of interest