[Federal Register Volume 60, Number 198 (Friday, October 13, 1995)]
[Proposed Rules]
[Pages 53328-53329]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-25405]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
Federal Motor Vehicle Safety Standards
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Denial of petition for rulemaking.
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SUMMARY: This document denies a petition for rulemaking submitted by
the Commonwealth of Pennsylvania Department of Transportation. The
petitioner requested that NHTSA issue regulations to reduce the
potential for tire tread separation and casing failure from new or
retreaded truck tires, including regulations that ensure the stability
of re-used casings, prescribe a maximum life of casings, and minimize
truck rim separations. While NHTSA shares the petitioner's safety
concerns, the agency believes that issuance of new safety requirements
for tires and rims would not be an appropriate way of addressing this
problem, which is primarily related to poor vehicle maintenance rather
than to tire and rim performance.
FOR FURTHER INFORMATION CONTACT: Ms. Terri Droneburg, Office of Vehicle
Safety Standards, National Highway Traffic Safety Administration, 400
Seventh Street SW., Room 5307, Washington, DC 20590. Telephone (202)
366-6617; facsimile (202) 366-4329. For legal issues: Mr. Walter Myers,
Office of Chief Counsel, National Highway Traffic Safety
Administration, 400 Seventh Street SW., Room 5219, Washington, DC
20590. Telephone (202) 366-2992; facsimile (202) 366-3820.
SUPPLEMENTARY INFORMATION:
Existing Standards
Federal Motor Vehicle Safety Standard (Standard) No. 117, Retreaded
pneumatic Tires, establishes performance, labeling, and certification
requirements for retreaded pneumatic passenger car tires. Among other
things, the standard requires retreaded passenger car tires to comply
with the tubeless tire resistance to bead unseating and the tire
strength requirements of Standard No. 109, New pneumatic tires.
Standard No. 117 also specifies requirements for casings to be used for
retreading, and certification and labeling requirements.
With respect to rims, Standard No. 110, Tire selection and rims,
applicable to passenger cars, establishes rim dimension requirements
and further specifies that in the event of a sudden loss of inflation
pressure at a speed of 60 miles per hour, rims must retain a deflated
tire until the vehicle can be stopped with a controlled braking
application. Standard No. 120, Tire selection and rims for motor
vehicles other than passenger cars, requires that vehicles other than
passenger cars equipped with pneumatic tires be equipped with rims that
are listed by the tire manufacturer as suitable for use with those
tires, and that rims be labeled with certain information.
The Petition
The Commonwealth of Pennsylvania (COP) Department of Transportation
submitted a petition for rulemaking requesting that NHTSA issue
regulations ``to reduce the potential for tread separation and casing
failure from new or re-cap truck tires.'' COP further requested that
the agency consider regulations ensuring the stability of re-used tire
casings that may require establishing a maximum life of casings.
Finally, COP requested that regulations be issued to ``further minimize
the potential for truck rims from separating from moving vehicles.''
COP stated that over the past several years it has noticed an
increase in separation of tire treads from truck tires and separations
from truck rims. COP stated that this is a dangerous situation in that:
* Other vehicles, especially passenger cars, vans, and motorcycles
can strike these tread separations, causing the vehicles to go out of
control and crash;
* With increased travel on the interstate highways the probability
of striking these pieces increases, particularly at night when
visibility is limited;
* Law enforcement officers and highway maintenance personnel are
vulnerable when trying to remove such debris from the roadways;
* Although COP's crash data does not readily identify crashes
resulting from striking tread debris on the road, COP has identified 15
cases in which tire portions caused crashes in 1993, and 2 crashes
resulting from vehicles striking truck rims on highways in 1993.
[[Page 53329]]
COP noted that there are standards for retreaded tires for
passenger cars, but not for vehicles other than passenger cars, and
stated that the problem is sufficiently significant to petition NHTSA
to take the actions discussed above.
Agency Decision
After a full and careful analysis of the requests of the COP in the
petition and the supporting rationale, NHTSA has decided to deny the
petition. The agency shares COP's concerns about the risk of crashes
created by tire scraps and broken wheels in the highway. However, NHTSA
believes that issuance of new safety requirements for tires and rims
would not be an effective way of addressing the problem, since the
problem is primarily related to poor vehicle maintenance rather than to
tire and rim performance.
Available information shows that tire tread separation results not
from failure of unstable tire casings, used or new, but from improper
use and/or poor tire maintenance. The University of Michigan conducted
a study entitled ``Large Truck Accidents Involving Tire Failure'' which
concluded that tread separation results from overloading and/or
underinflation of tires which can cause tread failure on both new as
well as retreaded tires. Specifically, the study showed that of tire
scraps collected nationwide, approximately 60 percent were from
retreads and 40 percent from original treads.
The cause of tire tread separations is related to the fact that
heat is a tire's worst enemy. A pneumatic tire will flex and heat up
during the first few miles of operation. If properly inflated, the air
pressure in the tire will increase until the heat generation due to
flexing and the heat loss due to ambient cooling reach equilibrium.
Underinflation and/or overloading, however, can distort that
equilibrium and cause the tire to produce very high temperatures,
ultimately beyond the capability of the tire to adequately dissipate.
At highway speeds, underinflation and/or overloading can produce tire
temperatures up to 240 deg.-265 deg. Fahrenheit. Such extreme
temperatures can cause tire disintegration, sidewall failure and/or
tread separation, regardless of the soundness of the casing.
The danger posed by underinflation/overloading of tires prompted
the Federal Highway Administration (FHWA), DOT, to issue regulations
prohibiting the operation of commercial vehicles under conditions of
tire underinflation or overloading (49 CFR 393.75). FHWA enforces those
requirements by roadside inspection programs.
Available data show that the great majority, if not nearly all,
tire and rim scraps on the roads are from vehicles other than passenger
cars. While the problem of tire underinflation is common both to
passenger cars and trucks, passenger cars are seldom operated in a
fully loaded condition. That is not the case with trucks, however,
especially commercial trucks which, for economic reasons, are often
loaded up to their gross vehicle weight rating (GVWR). For that reason,
therefore, when tires are underinflated, the likelihood of tire failure
is much greater for trucks than for passenger cars.
With regard to rims, the potential problem with wheel rims is not
so much that they break apart, but that the entire wheel and rim
assembly separates from the vehicle. Again, the leading causes of such
wheel separations from medium and heavy trucks, which constitute
approximately 0.3 percent of all truck accidents, are improper
tightening of wheel fasteners and bearing failure. Both those factors
are the result of inadequate or improper wheel maintenance.
For the reasons discussed above, NHTSA believes that improper
maintenance is primarily responsible for tread and wheel failure,
rather than tire/rim performance or unstable casings being used for
retreaded tires. Moreover, the agency is not aware of changes to tires
or rims that would address these problems. NHTSA therefore believes
that issuance of new safety requirements for tires and rims would not
be an appropriate or effective way of addressing the problems. Thus,
there is no reasonable probability that this agency would issue the
requested regulations at the conclusion of a rulemaking proceeding.
Accordingly, the petition of COP is denied.
NHTSA will continue to emphasize the importance of proper vehicle
maintenance, including proper tire inflation, in its various activities
and encourages similar efforts by other public and private sector
organizations.
Authority: 49 U.S.C. Secs. 322, 30111, and 30162; delegation of
authority at 49 CFR 1.50.
Issued on October 6, 1995.
Barry Felrice,
Associate Administrator for Safety Performance Standards.
[FR Doc. 95-25405 Filed 10-12-95; 8:45 am]
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