three studies on these longer combination vehicles. All of these
studies were mandated by, of course, the ISTEA legislation.
I have Dr. Kenneth Libbey with me. Ken helped â€” well, actually,
he directed our work on LVC's in the most recent report we did.
I will be using three charts, Mr. Chairman. I am aware of your
fondness for pictures and graphics. I would like to start with a lit-
tle background on what LCV is. I believe in front of you, you have
Senator EXON. Yes, I have it here.
GAO Distinguishing LCVs From Other Trucks
Rocky Mountain Double
I -26'-28' I I -26'-28' | | - 26' - 28' â€” |
Common Non-LCV Trucks
Combination With Single Trailer
Combination With Twin Trailers
| - -26'-28' -) ( - 26' -28'
Straigtit Truck With Trailer Connected
With Draw Bar
Source: American Trucking Associations and Transportation FTesearch Board.
Mr. Mead. This illustrates the three most common types of
longer combination vehicles. A long and short trailer, which is
called a Rocky Mountain double, a double 48-foot combination
called a turnpike double, and a triple, which has three 28-foot trail-
On the right side of the chart are combinations that are usually
not considered LVC's. In 1982, the Congress required that States
allow at least the double 28's and single 48's on the national truck
A double 28 is about 75 feet long, when you count the tractor and
the space between the trailers. We consider anything longer than
75 feet to clearly be a longer combination vehicle.
Now, the Federal weight limit for the interstate highways is
80,000 pounds, but the Congress has allowed grandfather excep-
tions to that limit. There are 14 western States that use these ex-
ceptions to allow one or more types of LVC's to operate.
GAO states and Turnpike Authorities
I ) Stales Not Allowing LCVs (30 Slates)
^3 Western Stales (14 Slates)
HI Turnpike Slates (6 Stales)
Looking at the map, which is my second chart and is on page 5
of my written statement, these States are shown with the diagonal
lines. And the six other States that are shown, these are shaded.
And in these States, the turnpike authorities have allowed some
The 1991 legislation prohibited further expansions of LCV oper-
ations beyond the routes and types approved by States on June 1,
I would like to make just one overall observation to what all our
work in this area says to us. LCV operations clearly can generate
economic benefits, and those economic benefits will probably out-
weigh their incremental impact on the highway and bridge infra-
structure. But they also pose safety risks.
They have not been a safety problem relative to other trucks on
highways with low traffic density, but we would urge caution in al-
lowing them on more heavily traveled highways and a variety of
safeguards that we are recommending, if any exceptions are made
to the current freeze.
I would cover just our key points. LVC's do reduce transportation
costs for the simple reason that fewer tractors and drivers are
needed and less fuel is used to transport a given amount of freight.
One study done for the trucking industry estimated annual sav-
ings of about $3.5 billion, or 3 percent of trucking costs.
LVC's, though, would also generate costs for the infrastructure.
They probably would not increase pavement wear. And that is be-
cause LVC's spread their higher gross weight over more axles than
But they would require some bridge replacements, widening of
interchanges, and provision of staging areas adjacent to interstate
Working with FAA, we would estimate that incremental costs
would be in the neighborhood of $1.3 billion for interstate bridge
replacements, $750 million to $2.2 billion for interchanges and
GAO Triple and T ui npike Double on
Chart 3 illustrates the difficulty that turnpike doubles would
have negotiating an estimated 75 percent of the interchanges on
the interstates. As you can see, part of the truck is going off into
the other lane.
All those estimates assume national operations of LVC's. If you
restrict them to the more suitable routes, both the costs and bene-
Senator ExoN. Let me ask you a question. Put that back up there
Is that an exit ramp or an entrance ramp, or is that a
Mr. Mead. Yes.
Senator ExoN. It is a ramp, where â€” in other words, there are no
turns on the interstate, per se, that would cause that problem. It
is when they exit or try to come back on the interstate system that
this situation occurs; is that correct?
Mr. Mead. That is correct.
Senator EXON. Thank you.
Mr. Mead. If only selective expansion of LCV routes occurred,
the beneficiaries would primarily be the so-called less than truck-
load companies. These are companies that consolidate shipments
for many different customers.
These companies already have an extensive terminal network in
the United States, and they can use these triple 28-foot trailers
just like they use the double 28's now for trips between their termi-
Large truckload companies that move cargo by the trailer load
from a shipper's dock to a receiver's dock would benefit from the
double 48-f^ot trailers, if a national network of highways were open
But without a national network, managing turnpike doubles
would be too cumbersome for their type of Dusiness. A patchwork
route system just does not provide this group in the industry bene-
I would like to turn to safety, which, as you pointed out, has to
be the priority consideration. The safety risks of LVC's stem from
operational characteristics that make them less stable and maneu-
verable than single trailer trucks.
LCV trailers tend to sway more, and sudden steering movements
can have an exaggerated or so-called crack-the-whip effect on the
very rear trailer.
LVC's can require longer distances to stop, and often lack the ac-
celeration that is needed to move smoothly with traffic. Many
States that allow LVC's have little data to monitor their oper-
ations, mainly because the data bases do not clearly distinguish be-
tween the LVC's that were on the left side of the chart and the
LVC's that were on the right side of the chart.
Also, we found that many States had no special requirements for
LCV drivers. We thought that driver qualifications were very criti-
cal to safe LVC's operations. And I should note that FAA is now
considering LCV driver experience requirements.
We also found that LVC's were not inspected as often as the sin-
gle combinations. And our analysis of inspection data suggested
that triples may actually be better maintained than your single
trailers, but that is probably not true of Rocky Mountain and turn-
The available data on the safety record on LVC's is extremely
limited. It is very thin. But it does suggest that the LVC's have not
been a safety problem relative to other trucks on the turnpikes of
western highways where they currently operate.
But you must view that record in the context of the less con-
gested nighways there and the operation of trucks by large compa-
nies with people with good driver records.
When we start talking about authorizing these trucks on more
heavily traveled highways or in proximity to major metropolitan
areas, LVC's could pose a greater risk to passenger traffic.
We made a series of suggestions in our most recent report to the
Congress and to FHWA that would only apply if Congress made
the policy judgment to lift the freeze, even if you wanted to lift it
Thank you, Mr. Chairman.
Senator ExoN. Mr. Mead, thank you very much.
[The prepared statement of Mr. Mead follows:]
Prepared Statement of Kenneth M. Mead
We appreciate the opportunity to testify on the results of our three issued reports
on the safety and economic impacts of longer combination vehicles (LCV).i At least
14 states and six turnpike authorities permit limited operation of long multiple-
trailer trucks commonly referred to as LCVs. LCVs can transport a given amount
of cargo at less cost than shorter combinations because fewer tractors and drivers
are needed and less fuel is used. As you know, our work regarding LCVs was man-
dated by the Intermodal Surface Transportation Efficiency Act (ISTTEA) of 1991.
Our testimony focuses on three LCV issues: (1) the economic impact on infrastruc-
ture â€” pavements, bridges, and interchanges â€” that result from expanded LCV oper-
ations; (2) the potential benefits from and industry's use of LCVs; and (3) the safety
of LCV use. In summary, we found the following:
â€¢ While generating benefits in the form of lower transportation costs, LCVs could
also generate costs for public agencies that provide and '^y for the infrastructure.
Analyses of benefits ana costs attributable to LCVs have been somewhat theoretical
because of the various assumptions used to analyze data. LCVs would probably not
increase pavement wear, but according to recent Federal Highway Administration's
(FHWA) analyses, nationwide use of LCVs on the interstate high v/ ay system could
require additional investments of $2.1 billion to $3.5 billion to replace bridges, im-
Erove interchanges, and provide staging areas for the breakdown and assembly of
CVs. Much of the projected infrastructure costs would be incurred in the more
densely populated areas of the country. If LCV expansion were limited to carefully
selected routes away from major population areas, the cost impact would be limited,
but the benefits would also be reduced.
â€¢ A 1990 analysis for the trucking industry projected that nationwide use of
LCVs on interstate and some primary highways would reduce annual trucking costs
by about 3 percent, or $3.4 billion. As annually recurring benefits, these savings
would exceed the one-time infrastructure investment costs estimated by FHWA.
However, expansion of the routes open to LCVs would benefit some sectors of the
trucking industry more than others. One sector, the large companies that consoli-
date packages or shipments under 10,000 pounds, could benefit immediately from
even a partial expansion of LCV routes. These less-than-truckload companies have
extensive terminal networks for collecting and distributing shipments, and they can
use triple 28-foot trailers for trips between terminals. The truckload sector, which
moves cargo by the trailerload from a shipper's dock to a receiver's dock, could bene-
fit from double 48-foot trailers if a national network of highways were open to them.
In the absence L'f snch a network, large truckload companies have not adjusted their
operation to accommodate doubles.
â€¢ Any decision to allow the expanded use of LCVs involves safety concerns as
well as economic factors. We reported in March 1992 that LCVs have operational
characteristics making them less stable and maneuverable than single-trailer
trucks. LCV trailers tend to sway more and sudden steering movements can be am-
plified toward the rear of LCVs. Furthermore, LCVs can require longer distances
to stop and often lack the acceleration needed to move smoothly with traffic. These
characteristics of LCVs could make them a greater safety risk than single-trailer
combinations if allowed on congested highways. We also found that states had lim-
ited data available to monitor LCV operations. Without such data, states may not
recognize emerging problems as traffic density grows and as less experienced drivers
and companies begin to operate LCVs. We believe that drivers' qualifications are
critical to the safety of LCV operation and thus have recommended that FHWA in-
clude LCV driver experience requirements in the Federal Motor Carrier Safety Reg-
In our August 1994 report, we said that if the Congress wishes to allow the ex-
panded use of LCVs, it should authorize the Secretary of Transportation to consider
exceptions to the freeze on LCV expansion only if requested by states and accom-
panied by the following:
â€¢ A state analysis of each proposed route to demonstrate its suitability in terms
of the density of traffic, condition of bridges, and adequacy of interchanges. States
1 Truck Safety: The Safety of longer Combination Vehicles Is Unknown, (GAO/RCED- 92-66,
Mar. 11, 1992). Longer Combination Trucks: Driver Controls and Equipment Inspection Should
Be Improved, (GAO/RCED-94-21, Nov. 23, 1993). Longer Combination Trucks: Potential Infra-
structure Impacts, Productivity Benefits, and Safety Concerns, (GAO/RCED-94-106, Aug. 9,
should determine whether additional infrastructure costs would be generated and
how these costs would be recovered.
â€¢ A certification that the state will enforce qualification standards for LCV driv-
ers, ensure adequate inspection of LCV equipment, and monitor the experience of
LCVs to identify any emerging safety problems or negligent carriers.
Appendix I discusses recommendations contained in our first two reports. These
recommendations to the Secretary of Transportation related to providing more com-
plete information on the safety of LCVS and for improving truck accident and travel
The most common LCVs are triples (a third 28-foot trailer added to two others),
turnpike doubles (a second long trailer added to a 45- or 48-foot single), and Rocky
Mountain doubles (a short trailer added behind a long one). Figure 1 illustrates
these LCVs and distinguishes them from combinations allowed to operate nation-
wide. Trucking companies, particularly in the West, also use variations of these con-
figurations (particularly different types of trailers) for special transportation needs.
FIGURE l: DISTINGUISHING LCVS FROM OTHER TRUCKS
Roclcy Mountain Double
I 26- - 28' 1 I Â»â– â– 2e 1 I M- â€¢ 28- i
Common Nof>.l.CV Trucks
ConKxnanon With Single Trailer
40' â– 53'
ConKxnebon Witti Tom Tnilen
1 2Â«' â€¢ 28' 1 I 2V â– 26-
StraigM Tnx* WKh Truer Connwled W)ffi Drew Bar
Source: American Trucking Associations and Transportation Research Board.
Since 1974, federal law has limited gross vehicle weight on interstate highways
to 80,000 pounds. However, 14 western states have allowed LCVs to operate at
heavier gross weights under "grandfather" exemptions from the federal law. In addi-
tion, turnpike authorities in six other states allow some LCV operations. LCV oper-
ations are often restricted. For example, LCVs may be limited to interstate high-
ways, and Nebraska only permits empty trailers on LCVs. On the other hand, Or-
egon allows triples on many state roads, and western states generally allow Rocky
Mountain doubles to operate widely. Figure 2 shows 14 western states and six turn-
pike authorities that allow some type of LCV to operate.^
^ISTEA required FHWA to identify state regulations allowing LCV operations as of June 1,
1991. FHWA officials said that by using the technical definition of an LCV stated in ISTEA,
their final rule will include some additional states allowing LCVs to operate and would not in-
clude Florida because its turnpike is not designated as part of the interstate system.
FIGURE 2: STATES AND TURNPIKE AUTHORITIES ALLOWING LCVS
SUIM NO AJk>Â«nnÂ« lCvi OO Sam)
waflvTt Sum* i^* SaMsl
LCVS COULD INCREASE INFRASTRUCTURE COSTS IF ALLOWED NATIONWIDE
Because LCVs spread their higher gross weight over more axles, they generally
do not increase pavement wear relative to shorter combinations and may actually
be less damaging. However, the higher gross weight of LCVs (especially turnpike
doubles) can pose a load capacity problem for some bridges. Because bridges are de-
signed to support much higher loads than expected, there is room for disagreement
on the margin of safety deemed necessary for loads on a bridge. At our request,
FHWA provided two different estimates or the number of bridges considered inad-
equate for LCV use and the cost to replace them. The Association of American Rail-
roads, which views turnpike doubles as a threat to rail business, favors using a con-
servative bridge capacity rating to estimate the potential impact of LCVs. When
FHWA used this rating, the analysis projected replacement costs of over $5 billion
for rural interstates and over $13 billion for urban interstates. The second analysis,
using a capacity rating considered by FHWA to be closer to that used in most states,
projected $248 million for rural interstates and $L1 billion for urban interstates.
In addition to bridge replacements, nationwide use of LCVs would require im-
provements to some interchanges as well as the provision of staging areas adjacent
to interstate highways where LCVs could be assembled and broken down. The cost
depends on how many points of access to the interstate system are deemed nec-
essary for effective LCV operations. In 1985, FHWA estimated these access costs at
between $750 million and $2.2 billion. A later study sponsored by the trucking in-
dustry questioned whether such extensive access was really needed. The study also
noted that many of the access problems were in densely populated eastern states
and that current states that allow LCVs already provided staging areas or let the
private sector provide its own.
Infrastructure costs could also increase if LCVs diverted freight from railroads to
highways. Several analyses have projected that nationwide use of LCVs (mainly
turnpike doubles) would lead to such diversion and would increase trucking ton-
miles from 5 to 16 percent. Most of these analyses were derived from a computer
simulation model maintained by the Association of American Railroads. However,
as explained in our August 1994 report, the model has significant shortcomings.
Most importantly, the model makes no allowance for ongoing productivity gains oy
the railroads, which have been substantial in recent years. These gains have made
the railroads more capable of preserving their market share against trucking com-
petition. As we reported, railroad intermodal service has improved and grown dra-
matically in recent years.^ The model also assumes that the truckload sector will
generally convert to using turnpike doubles, which is unlikely if LCV routes are ex-
BENEFITS AND INDUCTRY'S POTENTIAL USE OF LCVS
According to a 1990 study done for the trucking industry, opening the interstate
system and some primary highways to LCVs would lower annual trucking costs by
$3.4 billion (about 3 percent). Expanding routes open to LCVs would benefit some
sectors of the trucking industry more than others. For example, if expansion of LCV
routes were limited to highways with low traffic density, the potential benefits
would be lower and would apply mostly to companies that use triple 28-foot trailers
to transport consolidated small shipments between terminals. These less-than-truck-
load and package companies make extensive use of double 28-foot combinations na-
tionwide and add a third trailer wherever triples are legal.
On the other hand, officials of large truckload companies that sell by the trailer-
load see little opportunity in using turnpike doubles in the absence of a nationwide
highway network open to them. These companies would have to change their mode
of operation to use turnpike doubles (double 48-foot trailers). Their drivers often
travel from shipper's dock to receiver's dock to another shipper's dock and so on
until arriving at home. Such an operation recpjires close coordination even with sin-
gle-trailer combinations but would be substantially more complex with turnpike
doubles. Because turnpike doubles would be limited mainly to interstate highways,
companies would have to organize pickup and delivery at a customer's dock by sin-
gle trailer and then assemble doubles at staging areas. In the current fragmented
system of LCV routes, truckload companies have not found it practical to organize
Even with a nationwide highway network open to LCVs, it is questionable wheth-
er turnpike doubles would be widely used in the truckload industry. Small compa-
nies and owner-operators would have particular difficulty in managing the logistics
of wide area doubles operation. In some specific situations, however, small truckload
companies and private fleets have used turnpike doubles or Rocky Mountain doubles
profitably, and selective expansion of LCV routes would probably create some new
SAFETY CONCERNS MAY JUSTIFY LIMITS ON LCV EXPANSION
Our March 1992 and November 1993 reports showed that LCVs have operating
characteristics that can reduce their stability and maneuverability compared with
those of single-trailer vehicles, making it imperative that drivers be well qualified.
LCVs generally require longer distances to stop than single-trailer trucks. Stability
is more of a concern for triples than for doubles, since triples are more apt to sway,
and sudden steering movements can be amplified toward the rear. LCV aoubles can
present problems when merging into traflic because of their slow acceleration and
can also be very slow-moving on grades. Doubles also need a wider turn path than
do single-trailer trucks and can move outside their lane of travel, a condition called
Most of the data on traffic accidents fail to identify LCV configurations, making
it difficult to determine their safety record. The limited data available from a few
states and several large companies indicate that LCVs have not been a safety prob-
lem on the turnpikes and western highways where they have operated. Whether
this record could be maintained in heavier trafTic is open to question.
EfTorts to study the accident rates of multiple-trailer trucks have reached differing
conclusions concerning the safety of LCVs. Weaknesses in the data at both the na-
tional and state levels as well as differing study approaches contributed to the dif-
ferences. For example, the lengths of trailers are rarely recorded on accident forms,
making it impossible to separate accidents involving turnpike or Rocky Mountain
doubles from those involving the double 28-foot trailers operated nationwide. Also,
very little mileage data on LCVs are available, thus making it difficult to compare
accident rates of LCVs with those of single-trailer trucks.
3 Intermodal Freight Transportation: Combined Rail-Truck Service OfTers Public Benefits, But
Challenges Remain (GAO/RCED-93-16, Dec. 18, 1992).
Trucking industry ofTicials agree that to minimize the safety risks, LCVs need
well-qualiiied drivers as well as proper loading and brake adjustment. However, our
November 1993 report showed that most states that allow LCVs do little to monitor
LCV operations, regulate drivers' qualifications, or inspect the vehicles. While guide-
lines from both the Western Highway Institute and the Western Association of State
Highway and Transportation Officials recommend that drivers be experienced and
have good safety records, very few western states have any special requirements for
drivers. States also have not done special inspections of LCVs to monitor the condi-
tion of LCVs or the drivers' adherence to safety regulations, and some evidence sug-
gests that the longer combinations have been underrepresented in roadside inspec-
tion programs. Considering these factors, any expansion of LCV routes shoula be
subject to careful analysis and accompanied by better state supervision of LCV oper-
Any decision to allow the use of LCVs involves safety concerns as well as eco-
nomic factors. While LCVs may require some additional public investment in the
highway infrastructure, these costs appear to be exceeded by the recurring annual
benefits in the form of lower transportation costs. The safety issues are less easily
answered. The apparently good safety record of LCVs to date must be viewed in the
context of the less-congested highways where they have operated and the use of tri-
ples mainly by large less-than-truckload and package companies with good safety
records. A wider use of LCVs could bring them in proximity of major metropolitan
areas and on more-heavily traveled highways, which would entail greater risks to
the passenger traffic with whom trucks share the highways.
Analyses on the costs and/or benefits of LCVs have assumed that these vehicles
would operate nationwide. If, for safety reasons, LCVs were kept off the more-con-