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Science United States. Congress. Senate. Committee on Comm.

Truck lengths and safety : hearing before the Subcommittee on Surface Transportation of the Committee on Commerce, Science, and Transportation, United States Senate, One Hundred Third Congress, second session, September 14, 1994

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as a 57 foot trailer. There is not direct economic incentive for a motor carrier to in-
crease truck length.

There are no federal restrictions on states increasing the length of single trailers
and eleven states currently allow trailer length greater than 53 feet on the National
Truck Network. Yet, of these eleven, only Tour states, (Alabama, Florida, Kansas,
and Wyoming) have increased trailer length beyond 53 feet since 1982.

Question. Is there any increase or decrease in the safety of trailers related to
characteristics of the load being carried by the trailer?

Answer. We are not aware of any studies that correlate the safety performance
of trailers versus load characteristics. There are four elements involving cargo load-
ing, however, that may affect trailer stability.

The first element is the center of mass of the load within the trailer. The lower
the center of mass, the more stable the trailer. The trailer can be built to lower the
center of mass for a given load of cargo so that the trailer fioor is closer to the
ground or if the trailer length is longer. The actual load distribution on the trailer
also affects stability. Motor carriers load cargo so that the densest cargo is closest
to the ground and to the front of the trailer.

The second element is the weight of the cargo relative to the braking capability
of the truck. The federal bridge formula requires more axles as weight increases and
requires axles to be spaced to distribute the load. Truck brakes are required on all
axles of the vehicle. The more cargo weight carried by the trailer, the more axles
required and therefore, the more brakes applied.

The third element only involves combinations that have more than one trailer.
Carrier practice and some state laws require the heaviest trailers to be the closest
to the tractor. This arrangement improves tracking and braking stability.

The fourth element involves tank trucks transporting liquids. Cargo tanks that
are partially filled can generate liquid surge that can affect vehicle stability. Indus-
try practices to reduce tne likelihood of product surge during transportation include
keeping the cargo tank filled to capacity, putting compartments or bafiles inside the
tank, using low center-of-gravity or small bore tanks, and specialized driver train-
ing.

Question. Many claim that large trucks are more likely to be involved in a fatal
multi-vehicle crash than passenger vehicles. Please comment on this statement for
the committee.

Answer. The claim is not substantiated by government studies. According to DOT
data, heavy trucks account for 7 percent of miles traveled and are involved in 8 per-
cent of the fatal accidents. ^ These numbers do not indicate over-involvement of
trucks in fatal accidents.

In an accident involving a car and a truck, individuals in the car are more likely
to be injured than the individuals in the truck. This is due to the laws of physics.



1 Fatal Accident Reporting System 1991, National Highway Trafric Safety Administration,
March 1993, (DOT HS 807 954), tables 6, 7, 8 and 9.



100

If a smaller and lighter object is struck by a larger and heavier object, the smaller,
lighter object will generally sustain more damage.

Differences in weight are not just a factor in car and truck accidents. Based on
ten years of fatal accident data from NHTSA's Fatal Accident Reporting System
(FAKS), in over 90 percent of the fatal collisions involving a car and a motorcycle,
the driver of the motorcycle will be fatally injured and the auto driver will not be.
It would be absurd to most people to argue that the solution to the problem should
be to freeze or reduce the weight of cars.

The solution to the problem is to improve the safety of the vehicle, driver and
roadway. This is why the trucking industry has successfully supported the creation
of a single, classified license system for truck drivers, increased roadside safety in-
spections, elimination of the safety exemption in commercial zones, and bans on
radar detectors in commercial vehicles.

These efTorts have borne fruit. Over the last ten years (1983-1993) large truck fa-
talities ^ have decreased a total of 13.5 percent, and tractor-trailer fatalities have
decreased 22 percent. These improvements have been achieved while truck vehicle
miles traveled has increased 43 percent. (See following chart.)

Fatal Truck Crashes— 1983 to 1993

[Fatality Facts 1994 — Insurance Institute tor Higtiway Safety)



Year


Tractor trailers


Single unit


Unknown


Total


1983


4,238


768


464


5,403


1984


4,465


773


391


5,546


1985


4,513


831


359


5,610


1986 :


4,355


837


347


5,455


1987


4,254


873


407


5,469


1988


4,447


824


359


5,567


1989


4,225


848


351


5,360


1990


4,054


922


254


5,172


1991


3,418


953


437


4,728


1992


3,232


1,040


200


4,413


1993


3,469


1,187


170


4,759



(Note: Deaths in crashes invoMnj more than 1 truck type are Included more than once, except in totals )

It is important to note that the recent General Accounting Office study on longer
combination vehicles does not corroborate the claims of those who say that large
trucks are unsafe. According to GAO, "available data do not show that LCVs have
a safety problem in areas of low trafTic where they currently operate."^ The state-
ment is important because GAO has been studying the issue for over two and a half
years. If there were a problem, it is inconceivable that neither GAO nor any state,
university, or interest group has been able to quantify it.

Moreover, triples have an excellent safety record in the states where they operate.
According to the Oregon Public Utility Commission,"* "(t)riple trailer combinations
have a lower rate of truck-at-fault accidents than other trucks." The PUC found that
triples were three to four times safer than other types of trucks.

Question. Please provide the committee with any figures ATA may have for any
given year relative to the percentage of fatal truck crashes which are found to have
human factors as a cause.

Answer. The most recent data is from the NHTSA Report: Traffic Safety Facts
1993— Large Trucks. According to NHTSA,

(Oor 42 percent of the drivers of large trucks involved in fatal crashes in 1993,
police reported one or more errors or other factors related to the driver's behav-
ior associated with the crash.
This statistic includes all truck accidents involving fatalities, including single ve-
hicle truck accidents. When it focused only on truck accidents involving a car,
NHTSA found that

(i)n more than two-thirds (68 percent) of the two-vehicle fatal crashes involv-
ing a large truck and another type of vehicle, police reported one or more
(human] factors for the other driver and none for the truck ariver.



^NHTSA defines a 'large truck" as one with a gross vehicle weight rating greater than 10,000
pounds or more.

3 "Longer Combination Trucks: Potential Infrastructure Impacts, Productivity Benefits, and
Safety Concerns", General Accounting Office, August 9, 1994, GAO/RECD-94-106, page 6.

"PUC News, Oregon Public Utility Commission, March 2, 1994, Release 94-08.



101

This means that, in two-thirds of crashes involving a car and truck, the truck
driver had done nothing wrong and the error had been committed by the car driver.
The study does not conclude that the truck driver made an error in all of the re-
maining accidents. Rather, many of those accidents involved human factor problems
by both drivers or neither driver.

ATA has been working to address this problem by conducting educational pro-
grams around the country on how trucks and cars can share the road. We identify
traffic locations that are known problem areas and then describe driving techniques
that trucks and cars can use to avoid crashes.



Questions Asked by Senator Exon and Answers Thereto by Mr. Donohue

LONGER combination VEHICLE STABILITY

Question. Please provide the committee with the ATA response to the GAO report
and the Advocates for Highway Safety and Auto Safety (Advocates) claims which
contend that LCVs sway more and require longer distances to stop than single trail-
ers, and therefore could impose a greater safety risk on congested highways.

Answer. The GAO report does not conclude that "LCVs sway more and require
longer distances to stop than single trailers." Instead, GAO's extensive study refutes
the arguments made by Advocates. GAO said:

There has been some disagreement about LCVs stability during braking and
the distance required to stop. Under controlled test conditions with experienced
drivers, recommended equipment, properly adjusted brakes, and properly dis-
tributed loads, LCVs have oeen shown to stop in fairly short distances — com-
parable to single-trailer trucks.^ (emphasis added)
The issue then is not the underlying LCV, but how it is maintained and operated.
Sway is influenced by many things, including vehicle configuration. Turning inputs
are amplified as they pass through a system. Knowing such things occur, equipment
is designed to help control adverse side effects and drivers are trained in appro-
priate operating procedures.

Vehicle sway is regulated by the Federal Highway Administration.^ This regula-
tion requires that all combination vehicles be constructed such that any towed vehi-
cle does not deviate more than three inches to either side of the path of the vehicle
that tows it. Therefore, all vehicles are designed and must be maintained and driven
such that they do not produce dangerous levels of sway.

Sway can be reduced by going to longer trailers and by eliminating hitch points.
Trucking critics typically dwell on elimination of hitch points in their arguments
and ignore the safety benefits of additional length.

Eliminating hitch points can be counter-productive. It requires a dolly technology
that can only be used with short trailers, because the vehicle still needs to be able
to turn. Further, such dollies themselves can cause safety problems including total
vehicle rollover and the requirement for greater maneuvering space. Therefore, one
must be quite certain a problem exists before one attempts to correct it. The safety
record of LCVs indicates no safety problem in the way they are operated.

The Saskatchewan Highways and Transportation Department, in its report on
"The Safety Experience oi Large Trucks in Saskatchewan', noted that:

In general, it was found that vehicle type and configuration played a much
less important role in the overall accident experience oi large trucks than gen-
erally perceived by the public and transportation professionals. Safety, as it re-
lates to large trucks, clearly cannot be equated to vehicle type and/or configura-
tion. There are numerous other parameters like road, environmental, and driver
that appear to play much more important roles relative to safety than the vehi-
cle in general or vehicle type or configuration in particular. The area of driver
training probably provides the most cost efTective and productive target for
truck safety policies and programs. This is not to suggest that complacency is
appropriate with respect to the other major parameters (i.e. vehicle, road and
environment).

The major contributing factors to accidents involving large trucks in Sas-
katchewan are human conditions (32 percent), i.e. driver inattention, driver dis-
traction, had been drinking, driver inexperience, etc.; and environmental factors
(40 percent), i.e. animal action, slippery surface, loose gravel, obstructed view,
etc. Only about 35 percent of all accidents involving large trucks are in any way
related to vehicle type, vehicle configuration or vehicle stability. Further, of



^Ibid., page 2.

8 Federal Motor Carrier Safety Regulation (FMCSR) 49 CFR 393.70(a) Tracking.



102

those accidents where vehicle type, configuration or stability may be an issue,
it is not clear that any particular type or configuration is always better than
others.

Truck brakes have been designed to provide both panic stop capability and han-
dling control at the same time. They provide such capability and the ability to make
normal stops, all with a high degree of reliability. As with every other system of
the truck, changes and improvements are continually being made in the truck brak-
ing system.

Each time an axle is added to a truck, brakes are added as the federal safety
rules'' requires brakes on all wheels. There are two wheels (therefore, two brakes)
on every axle. LCVs have more axles, hence, added brake capability to handle their
increased cargo capacity. Adding an additional trailer does not slow the brake appli-
cation time for the other vehicles in the combination since towing trailers must meet
Federal Motor Vehicle Safety Standard 121 which establishes minimum brake per-
formance.

As evidenced by the millions of stops made each day, trucks, including LCVs, in-
corporate brake systems which have evolved to the point that they work so well in
traffic with cars that they are typically taken for granted. Except for a full panic
stop, car and truck braking is completely compatible. In the case of panic stops, the
greater sight distances enjoyed by truck drivers tend to result in an equalization
of truck and car performance.

Question. In light of the concerns of some people regarding the stability and ma-
neuverability of LCVs, what is ATA's position regarding the reasonableness of the
current freeze on LCVs as prescribed in the Intermodal Surface Transportation Effi-
ciency Act? Are there particular roads on which LCVs should not be permitted?

Answer. The LCV freeze created by ISTEA is illogical. It froze the size and
weight of LCVs that were operating on June 1, 1991, without regard to whether
those trucks could be operated safely on additional highways. If a truck of a certain
size and weight can operate safely and efficiently in one state, it should be safe in
another jurisdiction that has similar highways, traffic, geography, population den-
sity and no grandfather rights.

For example, a motor carrier in southeastern Wyoming hauls sugar beets from
fields located in Wyoming and Nebraska. Two separate Tleets of trailers must be
maintained to make the movement because of the freeze. This is because Nebraska
allows a second trailer that is only 20 feet long, eight feet shorter than what the
freeze allows in Wyoming. Drivers spend a great deal of time switching trailers in
situations involving a field that lies on both sides of the state line. While both fields
belong to the same agricultural producer, if the carrier enters the highway in Ne-
braska, one vehicle configuration is allowed.

If the vehicle enters the highway in Wyoming, another configuration must be
used. There is nothing logical about this and it costs a shipper $.05 to $.52 per ton
more to transport the beets in Nebraska. These types of inefiiciencies are putting
small carriers out of business and are adding cost to shippers and consumers.

There are about 4 million miles of highways in the United States. LCVs operate
on only 54,746 miles of roads, according to the GAO.® There are approximately
45,000 miles of interstate highways and toll roads; LCVs currently operate on only
17,464 of these miles. There are 166,648 miles of non-interstate, federal aid primary
designated national truck network miles. LCVs currently operate on only 37,282
miles of these highways.

Many roads are not suitable for LCV operations, either because of the number of
lanes, lane width, lack of shoulders, turning radius, grade, other geometric consider-
ations and/or traffic congestion.

However, many roads not currently open to LCVs are quite suitable and safe for
them. Rather than freezing the options of a state, states should be allowed to permit
operations of more productive and efficient vehicles on roads where they can operate
safely.

TRUCK LENGTH FREEZE

Question. ATA submitted testimony stating that the current Federal freeze on
LCVs is "illogical" because of non-uniformity in truck length limits. What changes
would ATA suggest, and why?

Answer. We suggest that the freeze be removed and states be allowed to change
LCV regulations.



^FMCSR 49 CFR 393.42.

^"Truck Safety, The Safety of I^onger Combination Vehicles is Unknown", United States Gen-
eral Accounting OfTice, GAO/RCED-92-66, March 11, 1992.



103

The freeze should be replaced with the approach suggested by a panel of experts
in Transportation Research Board Special Report No. 225, "Truck Weight Limits: Is-
sues and Options."® That report recommends that states regulate the weight of
trucks over 80,000 pounds by establishing a special permit program with designated
routes, maximum weights, new fee structures and safety restrictions.

In the study, TRB determined that the cost to the nation of rolling back the
weight to 80,000 pounds would be $7.76 billion annually. Because more trucks
would be placed on the highways, the rollback would result in 350 more fatalities
per year and 8,360 more injuries per year.

TRB's recommendations for special permits is consistent with the suggestions
made by the General Accounting Office in its report, "Longer Combinatifin Trucks
Potential Infrastructure Impacts, Productivity Benefits, and Safety Concerns."^"
GAO said that if the Congress wishes to allow the expanded 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 accompanied by the following:

• 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
should determine whether additional infrastructure cost would be generated and
how these costs would be recovered.

• 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 safety problems or negligent carriers.

As stated above, ATA believes that the LCV freeze is illogical. Moreover, we be-
lieve that it is bad public policy for Congress to dictate the size of vehicles. The
crash of a large airplane is likely to kill more people than a small airplane, but Con-
gress does not limit airplane size. A long train is more likely to block emergency
vehicles at grade crossings, but Congress does not regulate train length.

RELATIONSHIP OF TRUCK LENGTH LIMITS TO WEIGHT LIMITS

Question. Mr. Donaldson, on behalf of Advocates, submitted testimony which as-
serted that increases in truck length are followed by requests for increases in weight
limits, and thereby increases in accidents and road repair costs are experienced.
What is ATA's view of this trend?

Answer. The experience of the last decade proves Mr. Donaldson wrong. In 1982,
twenty four states allowed trailers that were 53 feet long or longer to operate. Now
every one of the contiguous 48 states allow 53 foot single trailers. However, contrary
to the assertion made by Mr. Donaldson, during this twelve year period only one
state (Arkansas) increased the gross weight limits for tractor semi-trailers.

The absence of weight increases was not because Congress enacted a freeze. There
is no Federal law or regulation that would have limited the ability of these states
to increase the gross weight for single-trailers operating on most of the roads in the
state. This is because the federal weight limits of 23 USC 127 apply only to the lim-
ited number of Interstate System highways in the state and the 1991 LCV freeze
applies only to trucks with multiple trailers.

However, we need to consider the impact of accidents and road repair costs if Con-
gress were to roll back truck size and weight and failed to provide for a growing
economy in the future. As described in the answer to question number 3, above, the
TRB calculated that the cost to the economy of rolling back weights would be $7.76
billion annually and result in more 350 deaths per year and 8,360 more injuries.
That is because the same amount of freight needs to move, regardless of the size
of the vehicle. Smaller vehicles mean more trucks and more vehicles causing wear
and tear.

Finally, we need to keep our options open for the future. Economic consultants
predict that by the year 2000, even with a conservative economic growth of 2.8 per-
cent per year, and assuming that intermodal freight traffic on railroads will double,
to meet the demands for jobs and a growing economy:

• trucks will have to haul 30 percent more freight,

• trucks will have to drive 31 percent more miles, and

• we will have to put 14 percent more trucks on the road.

I would like to again emphasize the need to keep all of our options open to meet
these needs, as long as we do not compromise safety.



*"Truck Weight Limits: Issues and Options" Special Report No. 225, (Washington, D.C.:
Transportation Research Board, 1990), 158, 231.

1° "Longer Combination Trucks Potential Infrastructure Impacts, Productivity Benefits, and
Safety Concerns", United States General Accounting Office, GAO/RCED-94-106, August 9, 1994.



104

NATIONAL HIGHWAY SYSTEM IMPLEMENTATION

Question. The Department of Transportation (DOT) has unveiled its proposal for
the NHS which will incorporate approximately 160,000 miles of interstate highway,
State highways, and county roads. What role, if any, should trucks lengths play in
implementing tiiis new NHS? Should the current freeze on truck lengths be ex-
tended to include the NHS?

Answer. Truck lengths should not be frozen as part of the NHS approval. The
NHS concept was a central part of the 1991 ISTEA legislation. ISTEA was revolu-
tionary in its efforts to provide increased flexibility to state and local governments
to meet transportation needs. One of the major exceptions to this flexioility is the
imposition on the states of a national freeze on LCVs.

There was not a comprehensive safety analysis prior to ISTEA justifying the need
for a freeze. GAO has now completed over two years of studies and three reports
called for by ISTEA and found no objective safety case for a freeze.

As states implement the NHS, they should ensure that roads can safely carry the
trucks that can legally operate on them. Therefore, unless FHWA's proposed truck
size and weight study shows difTerent results, the existing freeze on LCVs should
be ended and no federal freeze should be put on the length of single trailers.

NTS DEVELOPMENT BY DOT

Question. DOT is planning to submit a proposal in January 1995 for the develop-
ment of a National Transportation System (NTS) to promote the implementation of
an integrated, efficient intermodal transportation network. Are the issues of truck
length and safety integral elements to consider in the development of the NTS?

Answer. Only if objective studies of accident data show there is a safety problem
with a particular configuration should length be considered in the development of
the NTs. We should not begin the inquiry oy freezing a particular configuration. If
the vehicle is safe, states should be able to allow it to operate wherever it can oper-
ate safely.

It is important not to lose sight of the big picture. The NTS is not about trucking
or trucks. It is about jobs, the economy, trade and this country's ability to compete
in a world marketplace. One of the criticisms of LCV operations is that they reduce
a shipper's business with the railroads.

One significant example of how this is not the case is the experience of Coastal
Chem, Inc., a company based in Wyoming. In 1985 Coastal Chem shipped 51,915
tons of product by rail and 242,423 tons by truck (none by LCV).

In 1986, when Wyoming began allowing LCV operations. Coastal Chem moved
119,490 tons by rail, 53,596 tons by LCV and 261,285 tons by standard truck.

In 1993, they moved 211,200 tons by rail, 281,172 tons by LCV and 347,540 tons
by standard truck.

The NTS will improve our ability to move freight in a seamless intermodal envi-
ronment. Freezes and limitations applied to an NTS will only hamper the NTS goals
and the nation's ability to compete. We should be looking at creating a NTS concept
that improves our quality of life by promoting a seamless transportation system. We
should go in without preconceived iaeas and illogical freezes.

NAFTA AND THE LCV FREEZE

Question. In light of the passage of the North American Free Trade Agreement
(NAFTA) and efTorts to establish harmonious laws regarding truck length and
weights, what factors should be considered to enhance economic potential without


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