Document ID: NHTSA-2019-0055-0001
Agency: nhtsa
Document Type: Proposed Rule
Title: Federal Motor Vehicle Safety Standards: Compressed Natural Gas Fuel Container Integrity
Posted Date: 2019-06-21T04:00Z

[Federal Register Volume 84, Number 120 (Friday, June 21, 2019)]
[Proposed Rules]
[Pages 29145-29156]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-12895]

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DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. NHTSA-2019-0055]
RIN 2127-AL88

Federal Motor Vehicle Safety Standards; Compressed Natural Gas 
Fuel Container Integrity

AGENCY: National Highway Traffic Safety Administration (NHTSA), 
Department of Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: In response to petitions for rulemaking from the American 
Trucking Associations (ATA) and the Natural Gas Vehicles for America 
(NGVAmerica), NHTSA is proposing to amend the visual inspection 
labeling requirement in Federal Motor Vehicle Safety Standard (FMVSS) 
No. 304, ``Compressed natural gas fuel container integrity,'' to state 
that CNG fuel containers used on heavy vehicles should be inspected at 
least once every 12 months. NHTSA is proposing this change because CNG 
heavy vehicles are typically used in high-mileage commercial fleet 
operations and following the current mileage-based inspection interval 
on the label means conducting multiple visual inspections per year. 
NHTSA has tentatively concluded multiple visual inspections per year 
based solely on mileage would not improve vehicle safety for these 
high-mileage CNG heavy vehicles, and could potentially reduce safety. 
Because the current periodic visual inspection interval is intended for 
light vehicles and is consistent with the operation of these vehicles, 
no change is proposed to the periodic visual inspection interval for 
CNG fuel containers on light vehicles.

DATES: Comments must be received on or before August 20, 2019.
    Proposed compliance date: We propose the compliance date for the 
amendments in this rulemaking action would be one year after the date 
of publication of the final rule in the Federal Register. We propose to 
permit optional early compliance with the amended requirements.

ADDRESSES: You may submit comments to the docket number identified in 
the heading of this document by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the online instructions for submitting 
comments.
     Mail: Docket Management Facility, M-30, U.S. Department of 
Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery or Courier: West Building Ground Floor, Room 
W12-140, 1200 New Jersey Avenue SE, between 9 a.m. and 5 p.m. Eastern 
Time, Monday through Friday, except Federal holidays.
     Fax: 202-493-2251.
    Regardless of how you submit your comments, please mention the 
docket number of this document.
    You may also call the Docket at 202-366-9324.
    Instructions: For detailed instructions on submitting comments and 
additional information on the rulemaking process, see the Public 
Participation heading of the Supplementary Information section of this 
document. Note: all comments received will be posted without change to 
http://www.regulations.gov, including any personal information 
provided.
    Privacy Act: In accordance with 5 U.S.C. 553(c), DOT solicits 
comments from the public to better inform its decision-making process. 
DOT posts these comments, without edit, including any personal 
information the commenter provides, to www.regulations.gov, as 
described in the system of records notice (DOT/ALL-14 FDMS), which can 
be reviewed at www.transportation.gov/privacy. In order to facilitate 
comment tracking and response, we encourage commenters to provide their 
name, or the name of their organization; however, submission of names 
is completely optional. Whether or not commenters identify themselves, 
all timely comments will be fully considered.
    Docket: For access to the docket to read background documents or 
comments received, go to www.regulations.gov, or the street address 
listed above. Follow the online instructions for accessing the dockets.

FOR FURTHER INFORMATION CONTACT: Ian MacIntire, Office of 
Crashworthiness Standards (telephone: 202-493-0248) (fax: 202-493-
2990), or Daniel Koblenz, Office of Chief Counsel (telephone: 202-366-
2992) (fax: 202-366-3820). Address for both officials: National Highway 
Traffic Safety Administration, U.S. Department of Transportation, 1200 
New Jersey Avenu, SE, West Building, Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Executive Summary
II. Summary of Petitions
III. Background
IV. NHTSA's Analysis
V. Proposed Changes to the Visual Inspection Label
VI. Overview of Costs and Benefits
VII. Proposed Compliance Date
VIII. Rulemaking Analyses and Notices
IX. Public Participation
X. Appendix to the Preamble

I. Executive Summary

    This NPRM proposes to amend the label specified in S7.4(g) of FMVSS 
No. 304, ``Compressed natural gas fuel container integrity,'' by 
modifying the periodic visual inspection interval for CNG fuel 
containers installed on vehicles with a GVWR greater than 4,536 kg 
(``heavy vehicles'') to at least every 12 months (with no mileage 
interval).\1\ FMVSS No. 304 (S7.4(g)) currently requires that CNG fuel 
containers on all vehicles (regardless of GVWR) be permanently affixed 
with a label that states: ``This container should be visually inspected 
after a motor vehicle accident or fire and at least every 36 months or 
36,000 miles, whichever comes first, for damage and deterioration.'' 
NHTSA believes that

[[Page 29146]]

changing the periodic inspection interval for CNG fuel containers on 
heavy vehicles by removing the 36,000-mile mileage interval and 
reducing the 36-month time interval to a 12-month time interval would 
maintain safety while eliminating unnecessary visual inspections by 
high-mileage commercial motor carriers. These high-mileage carriers can 
reach the 36,000-mile mileage mark in as little as three months.
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    \1\ The term ``heavy vehicles'' as used in this NPRM includes 
all vehicles with a GVWR greater than 4,536 kg. Heavy vehicles 
include both ``medium duty'' vehicles (with a GVWR greater than 
4,536 kg and less than or equal to 11,793 kg) and ``heavy duty'' 
vehicles (with a GVWR greater than 11,793 kg), as those terms are 
used by the Federal Motor Carrier Safety Administration.
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    NHTSA initiated this rulemaking in response to petitions from the 
ATA (received April 13, 2016) and the NGVAmerica (received September 
16, 2016) requesting that NHTSA amend S7.4(g) of FMVSS No. 304. 
According to the petitioners, although the label's current inspection 
interval (every 36,000 miles or 36 months, whichever comes first) is 
appropriate for light vehicles (vehicles with a GVWR less than or equal 
to 4,536 kg) which are typically driven between 10,000 miles and 12,000 
miles annually, it is inappropriate for heavy vehicles, which are 
typically used in high-mileage commercial fleet operations. According 
to the petitioners, heavy duty vehicles (vehicles with a GVWR greater 
than 11,793 kg) are driven well over 100,000 miles annually and to 
follow the label's instructions, commercial operators of these vehicles 
need to conduct a detailed visual inspection of their vehicles' CNG 
fuel containers 3 to 4 times per year. The petitioners believe this 
creates an unreasonable burden on these commercial operators without a 
concomitant safety benefit.
    To address this issue, the petitioners request that the agency 
amend the visual inspection label requirement to remove the mileage 
interval for visual inspection, while keeping a time interval. However, 
the two petitioners differ on how long this time interval should be, as 
well as to what weight classes of vehicle this change should apply. ATA 
suggests that the visual inspection label recommend an inspection 
interval of at least every 36 months, whereas NGVAmerica suggests that 
the label recommend an inspection interval of at least every 12 months. 
In addition, ATA requests that the revised visual inspection interval 
apply to CNG fuel containers on high-mileage commercial CNG vehicles, 
while NGVAmerica requests that the revised visual inspection interval 
apply to CNG fuel containers on all CNG vehicles.
    After careful consideration, NHTSA has decided to partially grant 
the petitions for rulemaking. NHTSA proposes amending the FMVSS No. 304 
visual inspection label to state that the CNG fuel container should be 
visually inspected for damage and deterioration after a motor vehicle 
accident or fire, and either (a) at least every 12 months when 
installed on a vehicle with a GVWR greater than 4,536 kg or (b) at 
least every 36 months or 36,000 miles, whichever comes first, when 
installed on a vehicle with a GVWR less than or equal to 4,536 kg. 
NHTSA proposes to amend the periodic visual inspection interval for CNG 
fuel containers on heavy vehicles to ``at least once every 12 months,'' 
without including a mileage interval, to account for the fact that 
these vehicles are commonly used for high-mileage commercial purposes. 
The current periodic inspection interval (at least every 36,000 miles 
or 36 months, whichever comes first) was originally intended for light 
vehicles. NHTSA has tentatively concluded that reducing the frequency 
of inspections to once every 12 months for heavy vehicles aligns the 
requirement with the agency's intent that the inspection interval be 
reasonable and not excessive, and is appropriately tailored to the 
vehicle type (high-mileage commercial vehicles). In addition, a 12-
month interval for visual inspection aligns with a Federal Motor 
Carrier Safety Administration (FMCSA) requirement that inspections must 
be performed annually. (This NPRM does not propose changes to the 
periodic visual inspection interval for CNG fuel containers on light 
vehicles because the current periodic inspection interval (at least 
every 36,000 miles or 36 months, whichever comes first) is consistent 
with ensuring adequate safeguards for the operation of these vehicles. 
Petitioner NGVAmerica did not provide information supporting changing 
the interval to 12 months for the light vehicle population, so that 
aspect of its petition is denied.)
    NHTSA expects that revising the periodic inspection interval for 
heavy vehicles on the FMVSS No. 304 visual inspection label will result 
in fewer visual inspections being conducted. Many States require that 
commercial operators of CNG vehicles comply with the National Fire 
Protection Association (NFPA) voluntary standard NFPA-52, ``Vehicular 
Natural Gas Fuel Systems,'' which states that CNG fuel containers 
should be inspected in accordance with the container manufacturer's 
instructions (i.e., the required FMVSS No. 304 visual inspection 
label).\2\ Currently, 20 States (Alabama, California, Colorado, 
Connecticut, Delaware, Hawaii, Florida, Kentucky, Louisiana, Maine, 
Maryland, Massachusetts, Michigan, Nebraska, New Hampshire, Rhode 
Island, Texas, Vermont, Virginia, and Wisconsin) have adopted NFPA-52 
in their regulations. If the inspection interval specified by the FMVSS 
No. 304 label were amended as proposed in this NPRM, the commercial 
operators of CNG vehicles operating pursuant to NFPA-52, or those 
following a comparable practice of inspecting the containers as per the 
interval set forth in the label, would not have to inspect the CNG fuel 
containers as frequently. Taking into account the cost savings that 
would result from fewer visual inspections, NHTSA estimates the annual 
maintenance cost savings from this proposal range from $52.4 million to 
$83.84 million when fully implemented into the fleet, assuming the 
current CNG heavy vehicle fleet size remains unchanged. The agency 
believes this is a low estimate of the maintenance cost savings since 
CNG heavy vehicle sales are projected to steadily increase through 
2040.\3\
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    \2\ See https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=52.
    \3\ See Baker, et al., ``Alternative Fuel Vehicle Forecasts 
(April 2016),'' Texas A&M Transportation Institute, https://static.tti.tamu.edu/tti.tamu.edu/documents/PRC-14-28F.pdf.
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II. Summary of Petitions

    This rulemaking responds to two petitions requesting that NHTSA 
amend the FMVSS No. 304 visual inspection labeling requirement 
(S7.4(g)) for CNG fuel containers.
    NHTSA received the first of these petitions from American Trucking 
Associations (ATA) on April 13, 2016.\4\ ATA requests that we amend the 
visual inspection label for CNG fuel containers on high-mileage 
commercial vehicles to: ``This container should be visually inspected 
for damage and/or deterioration after a motor vehicle accident or fire, 
and at least every 36 months.'' ATA states that a visual inspection of 
the CNG fuel container is ``thorough, time consuming and expensive,'' 
and that ``requiring that it be done every 36,000 miles for vehicles 
that often travel over 100,000 miles per year is an unnecessary burden 
on the industry'' because high-mileage commercial fleets undergo an 
annual safety inspection which includes the fuel system, regardless of 
the label statement.
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    \4\ According to its website, ATA is the largest national trade 
association for the trucking industry and represents more than 
37,000 members covering every type of motor carrier in the U.S.
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    ATA states that field data collected by NGVAmerica and the Clean 
Vehicle Education Foundation (CVEF) on CNG vehicle incidents shows 
there were 20

[[Page 29147]]

CNG fuel container failures in the United States (U.S.) since 1984, and 
that most of these failures were because of external influences such as 
impact, heat, or chemical damage. ATA states some of the CNG fuel 
container failure incidents resulted in changes in voluntary industry 
codes and standards to ensure safe deployment of CNG vehicle 
technology, and that as a result of improvements in voluntary container 
standards, the CNG fuel container is the currently most reliable 
component within the high-pressure fuel system. According to ATA, the 
high reliability of CNG fuel containers means that decreasing the 
frequency of visual inspections would not reduce vehicle safety.
    NHTSA received the second petition from NGVAmerica on September 16, 
2016.\5\ NGVAmerica requests that we amend the statement for CNG fuel 
containers to: ``This container should be visually inspected for damage 
and/or deterioration after a motor vehicle accident or fire, and at 
least every 12 months.'' Like ATA, NGVAmerica believes that following 
the inspection interval specified in S7.4(g) for heavy vehicles would 
lead to detailed visual inspections of CNG fuel containers 3 to 4 times 
per year without a safety benefit, which unreasonably burdens 
commercial operators. NGVAmerica also believes that, because the 
inspection involves physically removing and later replacing parts of 
the vehicle's protective structure around the CNG tank (shielding), 
unnecessary inspections needlessly increase the risk of damage to the 
fuel system.
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    \5\ According to its website, NGVAmerica is a trade association 
that represents more than 230 companies, environmental groups, and 
organizations interested in the promotion and use of natural gas as 
motor fuel.
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    NGVAmerica requests that the new visual inspection label language 
be required for all vehicles, including light vehicles. However, 
NGVAmerica does express concern that changing the inspection interval 
on the label from once every 36 months or 36,000 miles to once every 12 
months would be burdensome for most light vehicle owners and operators, 
as it could potentially triple the frequency with which they currently 
conduct inspections. NGVAmerica suggests that this problem could be 
addressed by limiting the applicability of the new label to lower-
mileage vehicles, but does not propose specifically how to do so in its 
petition.

III. Background

a. FMVSS No. 304 and FMCSR 393.68

    FMVSS No. 304 specifies performance and labeling requirements for 
CNG fuel containers on passenger cars, multipurpose passenger vehicles, 
trucks, and buses that use CNG as a motor fuel, and to each container 
designed to store CNG as a motor fuel on-board any motor vehicle. 
(FMVSS No. 304, S3.) FMVSS No. 304 contains a number of performance 
requirements for CNG fuel containers to ensure adequate strength, 
durability, and pressure relief characteristics of CNG fuel containers 
installed on motor vehicles.
    Because proper maintenance of CNG fuel containers is critical to 
their long-term safety, NHTSA requires that CNG fuel containers be 
affixed with a label providing for visual inspection periodically and 
after a motor vehicle accident or fire. This promotes safe use of the 
containers and reduces the possibility that damage caused by external 
factors (including motor vehicle accidents and fires) would go 
undetected, a situation that could lead to CNG fuel container 
failure.\6\ The requirement for a visual inspection label is found in 
S7.4(g) of FMVSS No. 304. Currently, CNG fuel containers on all 
vehicles must be permanently labeled with the statement, ``This 
container should be visually inspected after a motor vehicle accident 
or fire and at least every 36 months or 36,000 miles, whichever comes 
first, for damage and deterioration.'' \7\
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    \6\ 60 FR 57943, November 24, 1995.
    \7\ A detailed account of the history of the FMVSS No. 304 
visual inspection requirement can be found in the appendix to this 
document.
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    Although NHTSA has the authority to require that all new CNG fuel 
containers be labeled in accordance with S7.4(g), NHTSA does not have 
the authority to require that commercial operators of CNG vehicles 
follow the inspection interval found on the visual inspection label. 
Rather, the in-use operation, inspection, repair, and maintenance of 
commercial motor vehicles is regulated federally by the FMCSA.\8\ FMCSA 
regulates commercial motor vehicles primarily thorough the promulgation 
and enforcement of Federal Motor Carrier Safety Regulations (FMCSRs).
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    \8\ See Motor Carrier Safety Act of 1999 (49 U.S.C. 113).
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    FMCSR 393.68, ``Compressed natural gas fuel containers,'' which is 
administered by FMCSA, directly addresses CNG fuel containers. It 
requires that all CNG fuel containers conform to FMVSS No. 304, and 
specifically requires that they meet the labeling requirements. It is 
the agency's understanding that commercial carriers that operate CNG 
vehicles typically treat the inspection interval on the FMVSS No. 304 
visual inspection label as the de-facto minimum inspection interval for 
the industry. (Further, as noted above, 20 States have adopted NFPA 
Code 52, ``Vehicular Natural Gas Fuel Systems,'' which specifies that 
commercial vehicle operators visually inspect CNG fuel containers in 
accordance with the visual inspection label permanently affixed to the 
container per FMVSS No. 304.)

b. FMCSA Research and Recommendation

    In March 2013, FMCSA issued a research report titled, ``Natural Gas 
Systems: Suggested Changes to Truck and Motorcoach Regulations and 
Inspection Procedures'' \9\ (herein referred to as the ``March 2013 
Report''), which provided recommendations for changes to the FMCSRs and 
other standards \10\ to accommodate and facilitate the use of natural 
gas as a motor fuel in commercial motor vehicles. FMCSA initiated this 
research project in 2012 to identify whether there are needed changes 
to the current FMCSRs and inspection procedures to specifically and 
fully address unique characteristics of natural gas used as a fuel. 
FMCSA's goal was to improve the safety of commercial motor vehicle 
operations by ensuring commercial motor vehicles powered by natural gas 
meet appropriate safety criteria at all times while operating on public 
roads. As part of its research, FMCSA conducted an extensive literature 
review of codes, standards, best practices, and lessons learned related 
to natural gas fueled heavy vehicles as well as a series of industry 
site visits to gather feedback.
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    \9\ FMCSA-RRT-13-044, ``Natural Gas Systems: Suggested Changes 
to Truck and Motorcoach Regulations and Inspection Procedures,'' 
March 2013. https://rosap.ntl.bts.gov/view/dot/83.
    \10\ North American Standard (inspection procedures and out-of-
service criteria) and FMVSS No. 304.
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    One recommendation in the March 2013 Report was for NHTSA to modify 
the required visual inspection label on CNG fuel containers by deleting 
the reference to mileage for commercial motor vehicles. The report 
notes the labeling requirement was originally intended for passenger 
cars, and that commercial motor vehicles, which typically travel more 
than 160,930 km (100,000 miles) per year, were not taken into account. 
The report also states that, for commercial motor vehicles, the 
reference to mileage in the current

[[Page 29148]]

visual inspection label results in at least three detailed inspections 
of the CNG fuel containers per year performed by CNG-trained mechanics, 
which is too burdensome and unnecessary. Accordingly, the report 
recommends that NHTSA amend the visual inspection label requirement of 
FMVSS No. 304 to delete the reference to mileage for commercial motor 
vehicles.

IV. NHTSA's Analysis

a. Introduction

    In general, CNG heavy vehicles are currently used in commercial 
fleet operations.\11\ Although the U.S. has an extensive natural gas 
distribution system in place, vehicle fueling infrastructure (i.e., 
availability of fueling stations) is limited. Therefore, natural gas as 
a vehicle fuel is most amenable to commercial fleet operations that 
install their own natural gas fueling stations and/or partner with 
other fleet operations. Because the initial cost of CNG vehicles is 
significantly higher than conventional diesel vehicles, commercial 
carriers who operate CNG vehicles tend to do so in high-mileage 
operations, so that they can more quickly recover the initial cost.\12\ 
As a result, natural gas as a motor fuel is gaining popularity among 
medium and heavy duty vehicle fleets such as shuttle, transit, and 
school buses, refuse trucks, street sweepers, and large haul truck 
tractor/trailers with centralized fueling operations.\13\ Natural gas 
is most commonly used as fuel by medium and heavy duty vehicle 
commercial fleet operations, because the price for natural gas has been 
low relative to diesel and gasoline,\14\ and refueling infrastructure 
can be centrally located for fleet operations.\15\
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    \11\ Baker, et al., ``Alternative Fuel Vehicle Forecasts (April 
2016),'' Texas A&M Transportation Institute, https://static.tti.tamu.edu/tti.tamu.edu/documents/PRC-14-28F.pdf.
    \12\ U.S. Department of Energy, ``Natural Gas Vehicles,'' 
Alternative Fuels Data Center, https://www.afdc.energy.gov/vehicles/natural_gas.html.
    \13\ https://static.tti.tamu.edu/tti.tamu.edu/documents/PRC-14-28F.pdf.
    \14\ For example, the national average price of CNG in April 
2018 was about 30 percent less than that of diesel.
    \15\ Baker, et al., ``Alternative Fuel Vehicle Forecasts (April 
2016),'' Texas A&M Transportation Institute, https://static.tti.tamu.edu/tti.tamu.edu/documents/PRC-14-28F.pdf.
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b. FMVSS No. 304's Inspection Label Was Based on Lower-Mileage Light 
Vehicles

    The petitioners justify their request to amend the FMVSS No. 304 
visual inspection label in part by arguing that the visual inspection 
label's current 36,000-mile mileage interval was intended for lower-
mileage light vehicles, and is not necessarily appropriate for higher 
mileage heavy vehicles. NHTSA has concluded that the petitioners are 
correct that the current mileage interval was intended for light 
vehicles, based on both the regulatory history of the visual inspection 
label requirement, and a comparison of the average annual vehicle miles 
traveled (VMT) by light versus heavy vehicles.
    NHTSA established the visual inspection label requirement in a 
final rule issued on November 24, 1995. In that rule, the Agency 
explained that it chose to recommend a visual inspection interval of 
12-months/12,000 miles because it was ``consistent with the recommended 
interval for many motor vehicle warranties and routine maintenance 
items.'' \16\ This meant that the agency tailored the visual inspection 
requirement to light vehicles, since the CNG vehicle fleet at the time 
was primarily comprised of light vehicles. The visual inspection label 
then changed to the current 36-month/36,000-mile interval in response 
to petitions for reconsideration of the November 24, 1995 final rule. 
Like the final rule itself, NHTSA's response to the petitioners for 
reconsideration of the visual inspection label was based on field data 
available at the time, which was primarily obtained from light 
vehicles.\17\ The visual inspection label has not been changed since.
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    \16\ 60 FR 57945, November 24, 1995.
    \17\ 61 FR 47086, September 6, 1996
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    A statistical analysis of mileage data collected by the U.S. 
Federal Highway Administration (FHWA) shows that the 3-year/36,000-mile 
interval on the inspection label is more consistent with the average 
annual VMT of light vehicles than of heavy vehicles.\18\ The average 
annual VMT in 2014 and 2015 for all vehicles (not just CNG vehicles) 
broken down by vehicle type, is shown in Table 1:
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    \18\ Data obtained from the FHWA Office of Highway Policy 
Information--Annual Vehicle Distance Traveled in Miles and Related 
Data--2015 by Highway Category and Vehicle Type. https://www.fhwa.dot.gov/policyinformation/statistics/2015/vm1.cfm.

                         Table 1--Average Annual VMT in 2014 and 2015 by Vehicle Type *
                                                [All fuel types]
----------------------------------------------------------------------------------------------------------------
                                                                                    All single          All
                      Year                           All light       All buses      unit trucks     combination
                                                     vehicles                         (SUTs)       trucks (CTs)
----------------------------------------------------------------------------------------------------------------
2014............................................          11,287          18,347          13,123          65,897
2015............................................          11,443          18,258          12,960          61,978
                                                 ---------------------------------------------------------------
Average.........................................          11,365          18,303          13,042          63,938
----------------------------------------------------------------------------------------------------------------
* Buses, SUTs, and CTs are overwhelmingly heavy vehicles.

    Table 1 indicates that an average light vehicle travels just shy of 
12,000 miles over 12 months and equates to approximately 36,000 miles 
over 36 months. By contrast, the average annual VMT of combination 
trucks (truck/tractor with trailer) is nearly 6 times that of light 
vehicles (passenger cars, vans, light trucks, and sport utility 
vehicles), and the average annual VMT of buses is 1.6 times greater 
than that of light vehicles.
    Although the single unit trucks (SUTs) \19\ figure is comparable to 
that of light vehicles, we think it is likely that CNG SUTs are 
typically used in high-mileage and centrally fueled fleet operations. 
This is because CNG vehicles have a relatively high upfront cost to 
operators, which means that they are generally used in high-mileage 
operations to recoup that cost and thus tend to have higher annual VMTs 
than average vehicles in their weight class.\20\ Accordingly, although 
NHTSA does not have precise VMT data on CNG SUTs, the agency believes 
that the average

[[Page 29149]]

annual VMT by CNG SUTs is likely significantly higher than the average 
reported in Table 1 for all SUTs.
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    \19\ SUTs are defined as single frame trucks with 2-axles and at 
least 6 tires or a GVWR greater than 4,536 kg. See https://www.fhwa.dot.gov/policyinformation/statistics/2015/vm1.cfm.
    \20\ U.S. Department of Energy, ``Natural Gas Vehicles,'' 
Alternative Fuels Data Center, https://www.afdc.energy.gov/vehicles/natural_gas.html.
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    For these reasons, NHTSA agrees with the petitioner's assessment 
that the current mileage interval on the visual inspection label was 
intended for light vehicles and is not consistent with medium and heavy 
duty vehicle CNG fleet operations due to the greater miles traveled 
annually by the latter vehicles. NHTSA seeks comment on the 
appropriateness of the current labeling requirement for high-mileage 
heavy vehicles. In addition, to focus on the average annual VMT for CNG 
heavy vehicles, the agency seeks comment and input on the average 
annual VMT of CNG vehicles by vehicle GVWR.

c. Cost Burden of Frequent Vehicle Inspections

    According to ATA's petition, following the current periodic visual 
inspection interval specified on the FMVSS No. 304 visual inspection 
label (i.e., 36,000 miles or 36 months, whichever comes first), means 
that CNG fuel containers on heavy duty vehicles need to be inspected 
three to four times per year, at an annual cost between $1,500 and 
$2,500 per vehicle.\21\ NHTSA tentatively agrees that this is a 
reasonable estimation of the annual cost burden imposed on high-mileage 
carriers.
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    \21\ This estimate is of the cumulative cost of all fuel tank 
inspections that can be attributed to following the inspection 
label.
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    According to ATA, the cost of a single inspection ranges between 
$200 and $500 per vehicle with an average cost of $350. This cost 
includes inspection by a trained and certified inspector and removal 
and replacement of shields or covers of the CNG fuel containers before 
and after the inspection, respectively. In addition, ATA expects a 
vehicle to have a two-day downtime for the inspection costing about 
$150 per day. Using the information provided by ATA, NHTSA estimates 
that the average cost of a single inspection is about $650 ($350 + 2 x 
$150).
    This information is supportive of the petitioners' views that 
multiple visual inspection of the CNG fuel container per year imposes 
an unreasonable economic burden on operators of high-mileage commercial 
CNG-fueled heavy vehicles given the apparent absence of a safety need 
for multiple inspections. NHTSA notes, however, that the agency has not 
conducted its own research on this subject and thus has no basis on 
which to independently corroborate those calculations. (Although the 
March 2013 FMCSA report concluded that frequent visual inspections did 
impose a cost on operators of commercial vehicles, it did not include 
hard calculations of what that cost would be.) We therefore seek 
comment and input on the frequency of visual inspections, cost of an 
inspection, number of days of downtime per inspection, and the cost of 
downtime.

d. Potential Safety Risks of Frequent CNG Fuel Container Inspections

    NGVAmerica argues in its petition that multiple detailed visual 
inspections of CNG fuel containers per year can increase the risk of 
damage to the fuel system.
    According to NGVAmerica, frequent visual inspections can increase 
risk of damage because visual inspections require that the fuel 
system's covers and shields be removed and reinstalled. Frequent 
removal and reinstallation of shielding and covers increases the risk 
of human error, such as leaving a bolt or fastener loose, over 
tightening a bolt or fastener, moving a fuel line out of place which 
could cause it to rub other components, replacing a bolt or fastener 
with one that is too long that rubs against other components, or 
replacing a bolt with one that is too short and does not provide proper 
clamping force. The petitioner believes that this risk cannot be 
eliminated even with improved training and feedback to the technicians. 
In addition, bolts and fasteners have a usable life cycle and frequent 
removal and replacement may increase wear and tear resulting in 
premature hardware failure.
    The agency seeks comment on the extent of potential damage to the 
fuel system and the associated safety risks posed by frequent visual 
inspections.

e. Field Data on CNG Vehicle/Container Failures

    ATA states in its petition that field data indicate that there are 
very few instances of container failures across all CNG-fueled 
vehicles, and that these failures were due to external influence, such 
as impact and excessive heat rather than insufficient inspection. NHTSA 
tentatively agrees with this assessment.
    CNG fuel containers are high pressure vessels and need more 
scrutiny to detect damage and deterioration than fuel tanks of diesel 
fueled vehicles because failure of a high-pressure vessel can be 
catastrophic. Nonetheless, according to ATA, between 1984 and 2015 
there were only about 20 known CNG fuel container failures in the U.S. 
and Canada. ATA attributes this low number to the high quality of CNG 
fuel containers due to voluntary industry standards.
    ATA states that the statistic it cites of approximately 20 canister 
failures from 1984 to 2015 is based on field data collected by the 
CVEF.\22\ NHTSA linked the source of ATA's information to a 
presentation, ``CVEF ACT Training,'' \23\ which reported there were 68 
CNG vehicle ``incidents'' in North America from 1984 to 2015.
---------------------------------------------------------------------------

    \22\ CVEF was funded by the U.S. Department of Energy's National 
Renewable Energy Laboratory, but all the data collected has been 
transferred to and it maintained by NGVAmerica. It is available at 
http://www.ngvamerica.org/media-center/technical-and-safety-documents/.
    \23\ Horne, Douglas, Dimmick, John, ``CVEF ACT Training,'' 
originally published on May 14, 2012. The document was updated on 
September 26, 2016. The document is available from NGVAmerica and in 
the docket of this NPRM.
---------------------------------------------------------------------------

    NHTSA obtained the CVEF Master Incident List \24\ underlying the 
``68 incidents'' statistic, and found that 19 of these incidents were 
CNG fuel container rupture failures. (The other ``incidents'' on the 
list were not container failures; they involved either a CNG leak or a 
release of CNG by Pressure Release Device (PRD) activation, which are 
typically caught during the routine pre-trip inspection that drivers 
must do every time they operate the vehicle.) Of the 19 CNG canister 
ruptures, 16 occurred in the U.S. and 3 occurred in Canada. Details of 
the 16 CNG fuel container failures in the U.S., broken down by 
container type,\25\ are shown in Table 2.
---------------------------------------------------------------------------

    \24\ CVEF Master Incident List is a list of CNG incidents world-
wide originally collected and documented by CVEF up to 2015. The 
document is maintained by NGVAmerica. A copy of the document is 
available in the docket of this NPRM.
    \25\ Because different types of CNG fuel containers experience 
different types of failure modes and are susceptible to different 
types of failure mechanisms, failures are grouped by container type. 
There are generally four types of CNG fuel containers. The type 
designation is based on the way the container is made and the 
material it is made out of (aluminum, steel, carbon fiber, etc.). 
Type 1 containers are all metal cylinders (steel or aluminum). Type 
2 containers have a thinner metal liner and a composite and wire or 
metal hoop ``wrap'' that provides reinforcement for the cylinders. 
Type 3 containers have a metal liner that is completely wrapped in 
composite/fiber resin. Type 4 containers are cylinders with a 
polymer liner wrapped in fiber.

[[Page 29150]]

              Table 2--Cause of CNG Fuel Container Failure Incidents in the U.S. From 1984 to 2015
----------------------------------------------------------------------------------------------------------------
                                              Number of CNG fuel container failures by container type
   Cause of CNG fuel container   -------------------------------------------------------------------------------
             failure                  Type 1          Type 2          Type 3          Type 4           Total
----------------------------------------------------------------------------------------------------------------
Fire or failure of pressure                    0               1               0               1               2
 relief device..................
External corrosion..............               0               0               0               0               0
Overpressurization..............               1               0               0               0               1
Physical damage.................               0               0               0               2               2
Combination of                                 0               3               0               0               3
 overpressurization, physical
 damage, and stress corrosion
 cracking.......................
Stress corrosion cracking from                 0               0               8               0               8
 acid/chemical exposure,
 degradation of glass fiber.....
                                 -------------------------------------------------------------------------------
    Total.......................               1               4               8               3              16
----------------------------------------------------------------------------------------------------------------

    Among the 16 CNG fuel container failures in the U.S. from 1984 to 
2015, one was a Type 1 container, four were Type 2 containers, eight 
were Type 3 containers, and three were Type 4 containers. Two CNG fuel 
container failures (one Type 2 and one Type 4) were caused by fire 
during which the pressure relief device (PRD) failed to operate. One 
Type 1 container failure was caused by overpressurization by faulty 
fueling systems. Three Type 2 container failures were caused by a 
combination of stress corrosion cracking, physical damage, and 
overpressurization resulting from improper installation of the 
container on the vehicle. Eight Type 3 container failures were caused 
by stress corrosion cracking from exposure to chemicals and acid that 
resulted in degradation of the glass wrap.\26\ Two Type 4 container 
failures were caused by physical damage. One Type 4 container failure 
was caused by an impact with an overpass during vehicle motion (the 
container was located on the roof), and another Type 4 container 
failure was caused by an impact with road debris while the vehicle was 
in motion (the container was mounted under the floor and not protected 
from damage). NHTSA notes that it is not known how long prior to some 
of these failures a visual inspection was performed.
---------------------------------------------------------------------------

    \26\ In 2001, the American National Standards Institute (ANSI) 
revised NGV 2, ``Basic Requirements for Compressed Natural Gas 
Vehicle (NGV) Fuel Containers,'' a voluntary industry standard for 
the manufacturers of CNG fuel containers to address the fact that a 
disproportionate number of container failures involved Type 3 
containers that ruptured due to stress corrosion cracking resulting 
from acid and chemical exposure that degraded the containers' glass 
fibers. Since the revision of NGV 2, there have been no known 
failures of this type.
---------------------------------------------------------------------------

    Periodic visual inspections are intended to detect external damage 
to the CNG fuel containers; it is possible inspections have found 
anomalies that undetected could have resulted in incidents such as 
those described above. However, data do not indicate the necessity of 
multiple visual inspections per year over a single annual inspection. 
In the 1980s and 1990s, the CNG fleet was composed of taxi cabs, 
delivery vans, and light trucks, i.e., vehicles whose CNG containers 
were labeled under FMVSS No. 304 as subject to an inspection interval 
of every 36 months or 36,000 miles. Given that the extremely low 
failure rate of CNG fuel containers (19 failures over 33 years) \27\ 
occurred during a time the containers were presumably only inspected 
every 36 months or 36,000 miles, it does not appear to NHTSA that there 
is a need for the heavy vehicle containers to be visually inspected 
every 3 to 4 months (which results from following the wording of the 
current FMVSS No. 304 label). Thus, NHTSA has tentatively concluded 
that multiple inspections per year are excessive to ensuring CNG fuel 
container safety.\28\ Accordingly, NHTSA has tentatively concluded that 
visually inspecting CNG fuel containers multiple times per year does 
not produce a safety benefit commensurate with the burden of 
inspection.
---------------------------------------------------------------------------

    \27\ To put this figure in perspective, the U.S. Department of 
Energy estimates that there are over 160,000 natural gas vehicles on 
U.S. roads today. See https://www.afdc.energy.gov/vehicles/natural_gas.html. NGVAmerica estimates that this figure is even 
higher at 175,000 vehicles. See https://www.ngvamerica.org/why-ngv/.
    \28\ NHTSA is aware of only the CVEF data on this subject. 
Commenters knowing of other data are encouraged to submit such 
information.
---------------------------------------------------------------------------

    The agency seeks comment and input on CNG vehicle incidents in the 
field, the effectiveness of visual inspections for identifying 
potential CNG container failures, and the frequency with which 
inspections conducted every 3- to 4-months reveal safety problems on 
heavy vehicles.

V. Proposed Changes to the Visual Inspection Label

    In consideration of the above, NHTSA is proposing to modify the 
FMVSS No. 304 label for visual inspection of CNG fuel containers to 
state: ``This container should be visually inspected for damage and 
deterioration after a motor vehicle accident or fire, and either (a) at 
least every 12 months when installed on a vehicle with a GVWR greater 
than 4,536 kg or (b) at least every 36 months or 36,000 miles, 
whichever comes first, when installed on a vehicle with a GVWR less 
than or equal to 4,536 kg.''
    NHTSA has tentatively decided to revise the periodic inspection 
interval for heavy vehicles to at least once every 12 months primarily 
for two reasons. First, a 12-month inspection period would be 
consistent and aligned with the annual inspection commercial motor 
vehicles undergo in accordance with FMCSR 396.17, ``Periodic 
inspection,'' which includes inspection of the fuel system and fuel 
container for leaks, damage, and deterioration.\29\ An annual visual 
inspection interval of CNG fuel containers on heavy vehicles would 
permit the inspection of the CNG fuel containers along with the rest of 
the fuel system, which is reasonable and practical.
---------------------------------------------------------------------------

    \29\ A 12-month inspection interval for CNG fuel containers is 
also consistent with the CNG fuel system inspection system developed 
by the NGVAmerica Technology &Development Committee and ATA's 
Technology Maintenance Council. See Compressed Natural Gas Fuel 
System Inspection Guidance,'' NGVAmerica Technology & Development 
Committee, https://www.ngvamerica.org/2017/12/04/new-cng-fuel-system-inspection-guidance-released/.
---------------------------------------------------------------------------

    Second, the agency believes that a 12-month inspection interval for 
heavy vehicles is appropriate because the agency lacks field data to 
support moving to a longer interval, such as every 36 months (as was 
suggested in the March 2013 Report). NHTSA is concerned that because 
heavy vehicles in commercial fleets travel significantly more miles 
than light vehicles, the CNG fuel containers on heavy vehicles may be 
exposed to more wear and tear than CNG fuel containers on light 
vehicles. In light of this concern, NHTSA has tentatively concluded 
that that an

[[Page 29151]]

annual visual inspection interval is appropriate because it is more 
likely to provide inspectors an opportunity to identify and remedy 
damage to the CNG fuel container and fuel system prior to a fuel 
container failure, as compared to a 36-month inspection interval. NHTSA 
seeks comment on its tentative decision to include a 12-month 
inspection interval on the visual inspection label for heavy vehicles 
rather than a 36-month period.
    Because NHTSA believes that the current periodic visual inspection 
interval on the visual inspection label is appropriate for light 
vehicles, the proposed language for the label includes different 
periodic inspection intervals for light and heavy vehicles. NHTSA 
believes that keeping a single, universally applicable label 
articulating the two different inspection intervals is preferable to 
requiring different labels for CNG fuel containers depending on the 
weight class of the vehicles because manufacturers of CNG fuel 
containers may not know the GVWR of the vehicle on which the fuel 
container will be installed at the time the manufacturer affixes the 
label.
    In addition, NHTSA believes that whether a vehicle has a GVWR 
greater than 4,536 kg (i.e., whether a vehicle is a heavy vehicle) is 
the proper way to determine whether the revised inspection interval is 
appropriate for that vehicle. Currently available data show nearly all 
new CNG heavy vehicles are used in commercial high-mileage fleet 
operations.\30\ Because of limited public fueling infrastructure and 
the high initial cost of CNG vehicles compared to conventional diesel 
vehicles, CNG as a motor fuel is mainly used in high-mileage commercial 
fleets that allow for quick recovery of initial cost. Thus, as a 
practical matter, the revised periodic inspection interval would affect 
virtually only vehicles with a GVWR greater than 4,536 kg used in 
commercial fleet operations.
---------------------------------------------------------------------------

    \30\ Baker, et al., ``Alternative Fuel Vehicle Forecasts (April 
2016),'' Texas A&M Transportation Institute, https://static.tti.tamu.edu/tti.tamu.edu/documents/PRC-14-28F.pdf.
---------------------------------------------------------------------------

    NHTSA seeks comment on CNG vehicles, with a GVWR greater than 4,536 
kg, that are used in low-mileage operations and are currently inspected 
at intervals greater than 12 months. We seek information on the number 
of such vehicles, whether the proposed 12-month inspection interval 
would increase the burden without commensurate safety improvements, and 
appropriate treatment of these vehicles for visual inspection of their 
CNG fuel containers.

VI. Overview of Costs and Benefits

    ATA stated the cost of a single visual inspection ranges between 
$200 and $500 per vehicle. This cost includes inspection by a trained 
and qualified inspector and removal and replacement of shields or 
covers of the CNG fuel containers before and after the inspection. ATA 
expects a vehicle to have a 2-day downtime for the inspection with a 
cost of about $150 per day. Using this information, NHTSA estimates the 
cost of a single inspection is $500 ($200 + $150 x 2) to $800 ($500 + 
$150 x 2) with an average of $650 ($350 + $150 x 2). For purposes of 
estimating costs and benefits, heavy vehicles were broken down into two 
categories: ``medium duty'' vehicles (with a GVWR greater than 4,536 kg 
and less than or equal to 11,793 kg) and ``heavy duty'' vehicles (with 
a GVWR greater than 11,793 kg).
    For determining the number of CNG heavy vehicles in the fleet, 
NHTSA reviewed available information on CNG vehicle stock from the U.S. 
Energy Information Agency (EIA) and from NGVAmerica. According to EIA's 
Annual Energy Outlook 2017, there were 2,150 CNG medium duty vehicles 
and 22,350 CNG heavy duty vehicles on the roads in 2015.\31\ By 
contrast, data from NGVAmerica indicates that there are 25,800 CNG 
medium duty vehicles and 39,500 CNG heavy duty vehicles.\32\ NHTSA 
believes that NGVAmerica's data is more accurate than EIA's data 
because NGVAmerica obtains stock data from its members, whereas EIA 
uses vehicle registration data. A count of CNG vehicle registrations 
would systematically undercount the number of CNG vehicles because many 
states do not require fuel type to be noted on the vehicle 
registration, and because many CNG heavy vehicles are conversions after 
first vehicle purchase. NHTSA therefore used data from NGVAmerica for 
estimating the fleet size of CNG heavy vehicles.
---------------------------------------------------------------------------

    \31\ U.S. Energy Information Administration, Annual Energy 
Outlook 2017, https://www.eia.gov/outlooks/aeo/.
    \32\ http://www.ngvamerica.org/vehicles/for-fleets/.
---------------------------------------------------------------------------

    For estimating the annual average VMT for heavy vehicles, NHTSA 
reviewed a published business model \33\ for heavy vehicle fleet 
operations that evaluated the benefit of converting to natural gas fuel 
over diesel fuel.\34\ The model took into account that a CNG heavy 
vehicle is on average about $40,000 more expensive than a similar 
conventional diesel engine heavy vehicle. The model also considered the 
price differential between diesel and natural gas, the cost of fueling 
infrastructure, vehicle maintenance costs, and the relative fuel 
economy of CNG and diesel vehicles to determine the minimum annual 
average VMT per CNG vehicle for a 20 percent return on investment. The 
model indicates that for a price differential of $1.25 per gallon 
between diesel and natural gas, the minimum annual average VMT per CNG 
vehicle required to maintain a 20 percent return on investment is 
75,000 miles for a medium duty vehicle and 123,000 miles for a heavy 
duty vehicle. Based on this information, to harmonize these numbers 
with current label, the agency selected an annual average VMT for 
medium duty vehicles of 72,000 miles and that for heavy duty vehicles 
of 108,000 miles to calculate visual inspection costs. Therefore, CNG 
fuel containers on heavy duty vehicles require on average about 3 
visual inspections annually, and those on medium duty vehicles require 
on average about 2 visual inspections annually under the current visual 
inspection label specified in FMVSS No. 304. We seek comment on the 
accuracy of this model, and on the reasonableness of its underlying 
assumptions.
---------------------------------------------------------------------------

    \33\ Dee, Anna Lea, ``What Set of Conditions Would Make the 
Business Case to Convert Heavy Trucks to Natural Gas?--a Case 
Study,'' National Energy Policy Institute, 2012. This document is 
available in the docket of this NPRM.
    \34\ NHTSA did not use the VMT data in the Annual Energy Outlook 
2017 (AEO2017) because the agency believes it underestimates the 
size of the CNG heavy vehicle fleet, and it is not consistent with 
the results from the business models for CNG vehicle fleet 
operations.
---------------------------------------------------------------------------

    The proposed periodic visual inspection interval of 12 months for 
CNG fuel containers on heavy vehicles would reduce the average number 
of visual inspections in a year by 2 for heavy duty vehicles and by one 
for medium duty vehicles, assuming that vehicle operators followed the 
label. Using the above information, NHTSA estimated the total cost 
savings from the proposed update of the visual inspection label for the 
CNG heavy vehicle fleet in the future when all the CNG heavy vehicles 
have CNG fuel containers with the proposed visual inspection label 
(Table 3). The analysis in Table 3 assumes that the CNG heavy vehicle 
fleet size in the future when all the CNG heavy vehicles would be 
equipped with the updated visual inspection label is the same as the 
current CNG medium and heavy duty vehicle fleet size and assumes that 
all vehicles will have inspections as directed by the label.

[[Page 29152]]

 Table 3--Estimates of Annual Cost Savings From the Proposed Update of the Visual Inspection Label for CNG Heavy
                                                    Vehicles
                  [Estimates in 2017 dollars and based on the current heavy vehicle fleet size]
----------------------------------------------------------------------------------------------------------------
                                                                                Cost of Inspection
                                                                 -----------------------------------------------
                                                                        Low           Average          High
----------------------------------------------------------------------------------------------------------------
Cost of Single Inspection (a)...................................            $500            $650            $800
Number of CNG Heavy Duty Vehicles (b)...........................          39,500          39,500          39,500
Number of CNG Medium Duty Vehicles (c)..........................          25,800          25,800          25,800
Number of Inspections Reduced Per Year for Heavy Duty Vehicles                 2               2               2
 by the Proposal (d)............................................
Number of Inspections Reduced Per Year for Medium Duty Vehicles                1               1               1
 by the Proposal (e)............................................
Cost Reduction for Heavy Duty Vehicles, (f) = (a) x (b) x (d) in        $39.50 M        $51.35 M        $63.20 M
 Millions (M)...................................................
Cost Reduction for Medium Duty Vehicles, (g) = (a) x (c) x (e)          $12.90 M        $16.77 M        $20.64 M
 in Millions (M)................................................
                                                                 -----------------------------------------------
    Total Cost Saving (f) + (g) in Millions (M).................        $52.40 M        $68.12 M        $83.84 M
----------------------------------------------------------------------------------------------------------------

    The potential annual cost savings because of the reduced number of 
CNG fuel container inspections per year for heavy vehicles ranges 
between $52.40 million to $83.84 million with an average cost savings 
of $68.12 million when the proposed inspection label is fully 
implemented into the fleet, assuming the current CNG heavy vehicle 
fleet size remains unchanged. The above analysis is likely a low 
estimate of the total cost saving because projections indicate the 
annual sale of CNG heavy vehicles used in commercial fleets will 
increase from 4,250 in 2015 to 68,000 in 2040.\35\ \36\ NHTSA seeks 
comment on the above analysis and the data used to support the 
analysis.
---------------------------------------------------------------------------

    \35\ Baker, et al., ``Alternative Fuel Vehicle Forecasts (April 
2016),'' Texas A&M Transportation Institute, https://static.tti.tamu.edu/tti.tamu.edu/documents/PRC-14-28F.pdf.
    \36\ While NHTSA did not use the AEO2017 data in its cost/
benefit analysis due to underreporting of the current size of the 
CNG fueled heavy vehicle fleet, we note that the AEO2017 data 
estimates an increase in the CNG medium and heavy duty vehicle fleet 
by 2040. According to AEO2017 projected estimates, there would be 
16,335 CNG medium duty vehicles and 74,469 CNG heavy duty vehicles 
in 2040. By contrast, the AEO2017 estimates that in 2015, there were 
2,150 CNG medium duty vehicles and 22,350 CNG heavy duty vehicles.
---------------------------------------------------------------------------

    As noted above, given the extremely low failure rate of CNG 
containers in the field (19 failures over 33 years), NHTSA has 
tentatively concluded that changing the periodic visual inspection 
interval of CNG fuel containers on heavy vehicles from ``36 months or 
36,000 miles, whichever comes first,'' to an annual inspection would 
not result in a reduction in safety. NHTSA notes that the agency has 
reached out to multiple potential sources of CNG vehicle data, 
including businesses that use CNG trucks, businesses that conduct 
inspections of CNG trucks, and trade associations that represent users 
of CNG trucks, for information on potential safety impacts of reduced 
inspections (in terms of both reduced potential damage discovery and 
reduced potential damage caused by intrusive tank teardown 
inspections). While we received some anecdotal feedback about the 
infrequency with which visual inspections caught potential safety 
issues, no source could provide us with comprehensive, substantive data 
on the effectiveness of periodic visual inspections. Accordingly, the 
agency seeks comment and input on CNG vehicle incidents in the field, 
especially regarding the effectiveness of multiple annual visual 
inspections, and the risk of damage to CNG tanks as a result of 
excessive inspection.
    The agency notes that, since it is not changing the requirement 
that all vehicles need a label, it does not believe that the textual 
changes to the label proposed here will lead to any significant costs 
associated with creating and installing the label. NHTSA estimates a de 
minimis cost impact, as manufacturers would be replacing a current 
label with a new one with different wording. The new label may need to 
be slightly larger because of wording changes, and there would be a 
one-time cost of redesigning the label, but all in all the costs of 
this rulemaking would be negligible when distributed among all CNG 
vehicles sold.

VII. Proposed Compliance Date

    We believe the proposed change in the visual inspection label on 
CNG fuel containers would alleviate the cost burden associated with 
multiple visual inspections per year for heavy vehicles and is 
supported by CNG fuel container manufacturers, CNG vehicle 
manufacturers and integrators, operators of CNG-fueled heavy vehicle 
fleets, and voluntary standards organizations that are members of 
NGVAmerica.\37\ Therefore, we are proposing a compliance date of one 
year after the date of publication of the final rule in the Federal 
Register, with optional early compliance permitted. We believe one year 
is sufficient time to make needed changes to the visual inspection 
label for CNG fuel containers with no additional cost, and that 
permitting early compliance will provide manufacturers with 
flexibility.
---------------------------------------------------------------------------

    \37\ Members of NGVAmerica include the CSA group (a standards 
development organization in North America), manufacturers of CNG 
fuel containers, manufacturers and integrators of CNG-fueled 
vehicles, and CNG vehicle fleet operators. http://www.ngvamerica.org/about-us/.
---------------------------------------------------------------------------

VIII. Rulemaking Analyses and Notices

Executive Order 12866, Executive Order 13563, and DOT Regulatory 
Policies and Procedures

    NHTSA has considered the impact of this rulemaking action under 
Executive Orders 12866 and 13563. This action was not reviewed by the 
Office of Management and Budget under these executive orders. This NPRM 
is not considered to be significant under the Department of 
Transportation's regulatory policies and procedures (44 FR 11034; Feb. 
26, 1979). NHTSA is proposing to modify the required label for visual 
inspection of CNG fuel containers to specify that the container should 
be visually inspected for damage and deterioration after a motor 
vehicle accident or fire, and either (a) at least every 12 months when 
installed on a vehicle with a GVWR greater than 4,536 kg or (b) at 
least every 36 months or 36,000 miles, whichever comes first, when 
installed on a vehicle with a GVWR less than or equal to 4,536 kg. 
Based on an analysis of CNG fuel container failures in the field, NHTSA 
believes this change will not lead to a reduction in safety. NHTSA 
believes that the only substantive effect of this proposal would be to 
eliminate unnecessary visual inspections of CNG

[[Page 29153]]

fuel containers by operators of high-mileage commercial CNG vehicles.
    NHTSA estimates the proposed change would potentially reduce the 
number of visual inspections per year by approximately 2 inspections 
for heavy duty CNG vehicles and by approximately 1 inspection for 
medium duty CNG vehicles. The agency further estimates that the 
elimination of these visual inspections will result in an average 
annual cost savings of $68.12 million when fully implemented into the 
fleet, assuming the current CNG heavy vehicle fleet size remains 
unchanged.

Executive Order 13771

    Executive Order 13771 titled ``Reducing Regulation and Controlling 
Regulatory Costs,'' directs that, unless prohibited by law, whenever an 
executive department or agency publicly proposes for notice and comment 
or otherwise promulgates a new regulation, it shall identify at least 
two existing regulations to be repealed. In addition, any new 
incremental costs associated with new regulations shall, to the extent 
permitted by law, be offset by the elimination of existing costs. Only 
those rules deemed significant under section 3(f) of Executive Order 
12866, ``Regulatory Planning and Review,'' are subject to these 
requirements. As discussed below, this rule is not a significant rule 
under Executive Order 12866 and, accordingly, is not subject to the 
offset requirements of 13771.
    NHTSA has determined that this NPRM is a deregulatory action under 
E.O. 13771, as it imposes no costs on manufacturers of CNG fuel 
containers, who must already meet the current visual inspection 
labeling requirement, and it proposes changes to FMVSS No. 304 that 
would have the effect of reducing the cost burden of multiple visual 
inspections of CNG fuel containers on heavy vehicles without any loss 
in safety, as described above.

Regulatory Flexibility Act

    Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq., 
as amended by the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) of 1996), whenever an agency is required to publish a notice 
of proposed rulemaking, it must prepare and make available for public 
comment a regulatory flexibility analysis that describes the effect of 
the rule on small entities (i.e., small businesses, small 
organizations, and small governmental jurisdictions) unless the head of 
an agency certifies the proposal will not have a significant economic 
impact on a substantial number of small entities. The Small Business 
Administration's regulations at 13 CFR part 121 define a small 
business, in part, as a business entity ``which operates primarily 
within the United States.'' (13 CFR part 121.105(a)). SBREFA amended 
the Regulatory Flexibility Act to require Federal agencies to provide a 
statement of the factual basis for certifying that a proposal will not 
have a significant economic impact on a substantial number of small 
entities.
    I certify this NPRM would not have a significant impact on a 
substantial number of small entities. The changes proposed in this NPRM 
are entirely deregulatory; any small operators who may be affected by 
this NPRM would see a reduction in maintenance costs because of reduced 
number of CNG fuel container inspections.

National Environmental Policy Act

    NHTSA has analyzed this rulemaking action for the purposes of the 
National Environmental Policy Act (42 U.S.C. 4321 et seq.), as amended. 
The agency has determined that implementation of this action will not 
have an adverse impact on the quality of the human environment. The 
modification in the visual inspection label for CNG fuel containers 
would have the consequence of reducing the annual inspection costs for 
CNG heavy vehicle owners and operators, which would make them more 
cost-effective in fleet operations and incentivize their purchase by 
fleet operators.

Executive Order 13132 (Federalism)

    NHTSA has examined today's NPRM pursuant to Executive Order 13132 
(64 FR 43255; Aug. 10, 1999) and concluded that no additional 
consultation with States, local governments, or their representatives 
is mandated beyond the rulemaking process. The agency has concluded the 
proposal does not have sufficient federalism implications to warrant 
consultation with State and local officials or the preparation of a 
federalism summary impact statement. The proposal does not have 
``substantial direct effects on the States, on the relationship between 
the national government and the States, or on the distribution of power 
and responsibilities among the various levels of government.''
    NHTSA rules can have preemptive effect in two ways. First, the 
National Traffic and Motor Vehicle Safety Act contains an express 
preemption provision:
    ``When a motor vehicle safety standard is in effect under this 
chapter, a State or a political subdivision of a State may prescribe or 
continue in effect a standard applicable to the same aspect of 
performance of a motor vehicle or motor vehicle equipment only if the 
standard is identical to the standard prescribed under this chapter.'' 
49 U.S.C. 30103(b)(1).
    It is this statutory command by Congress (and not today's proposed 
rulemaking) that preempts any non-identical State legislative and 
administrative law addressing the same aspect of performance, so 
consultation would be inappropriate.
    Second, the Supreme Court has recognized the possibility, in some 
instances, of implied preemption of State requirements imposed on motor 
vehicle manufacturers, including sanctions imposed by State tort law. 
That possibility is dependent upon there being an actual conflict 
between a FMVSS and the State requirement. If and when such a conflict 
exists, the Supremacy Clause of the Constitution makes the State 
requirements unenforceable. See Geier v. American Honda Motor Co., 529 
U.S. 861 (2000), finding implied preemption of state tort law on the 
basis of a conflict discerned by the court,\38\ not on the basis of an 
intent to preempt asserted by the agency itself.
---------------------------------------------------------------------------

    \38\ The conflict was discerned based upon the nature (e.g., the 
language and structure of the regulatory text) and the safety-
related objectives of FMVSS requirements in question and the impact 
of the State requirements on those objectives.
---------------------------------------------------------------------------

    NHTSA has considered, pursuant to Executive Orders 13132 and 12988, 
whether the proposals of this NPRM could or should preempt State common 
law causes of action. To this end, the agency has examined the nature 
(e.g., the language and structure of the regulatory text) and 
objectives of this proposal and finds that this NPRM is not intended to 
preempt State tort law that effectively imposes a higher standard on 
regulated entities than that would be established by today's proposed 
rule. The change proposed in this NPRM amends a labeling requirement 
that applies to newly manufactured CNG fuel containers; it does not to 
conflict with the establishment of a higher standard of safety by means 
of State tort law that applies to the same subject matter (i.e., 
adequate labeling of CNG fuel containers). Without any conflict, there 
could not be any implied preemption of state law, including state tort 
law.

Executive Order 12988 (Civil Justice Reform)

    With respect to the review of the promulgation of a new regulation, 
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR 
4729; Feb.

[[Page 29154]]

7, 1996), requires Executive agencies make every reasonable effort to 
ensure the regulation: (1) Clearly specifies the preemptive effect; (2) 
clearly specifies the effect on existing Federal law or regulation; (3) 
provides a clear legal standard for affected conduct, while promoting 
simplification and burden reduction; (4) clearly specifies the 
retroactive effect, if any; (5) specifies whether administrative 
proceedings are to be required before parties file suit in court; (6) 
adequately defines key terms; and (7) addresses other important issues 
affecting clarity and general draftsmanship under any guidelines issued 
by the Attorney General. This document is consistent with that 
requirement.
    Pursuant to this Order, NHTSA notes as follows. The issue of 
preemption is discussed above. NHTSA notes further there is no 
requirement that individuals submit a petition for reconsideration or 
pursue other administrative proceedings before they may file suit in 
court.

Privacy Act

    All submissions, including public comments on this NPRM, will be 
placed in the docket. Anyone is able to search the electronic form of 
all documents received into any of our dockets by the name of the 
individual submitting the document (or signing the document, if 
submitted on behalf of an association, business, labor union, etc.). 
You may review DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (Volume 65, Number 70; Pages 
19477-78).

Paperwork Reduction Act

    Under the Paperwork Reduction Act of 1995 (PRA), a person is not 
required to respond to a collection of information by a Federal agency 
unless the collection displays a valid OMB control number. There are no 
information collection requirements associated with this NPRM.

National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, as amended by Public Law 107-
107 (15 U.S.C. 272 note), directs the agency to evaluate and use 
voluntary consensus standards in its regulatory activities unless doing 
so would be inconsistent with applicable law or is otherwise 
impractical. Voluntary consensus standards are technical standards 
(e.g., materials specifications, test methods, sampling procedures, and 
business practices) that are developed or adopted by voluntary 
consensus standards bodies, such as the SAE International. The NTTAA 
directs us to provide Congress (through OMB) with explanations when the 
agency decides not to use available and applicable voluntary consensus 
standards.
    FMVSS No. 304 has historically drawn largely from ANSI NGV 2, and 
the proposed changes in this NPRM to the visual inspection label were 
made in accordance with data provided by NGVAmerica and ATA and the 
recommendations developed by industry technical working groups.\39\
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    \39\ The NGVAmerica Technology & Development Committee's 
Guidance on Fuel System Inspection published in November 2017 
specifies annual visual inspection for CNG fuel containers on heavy 
vehicles as a practical approach to inspection and maintenance of 
the fuel container and fuel system which would match intervals and 
procedures with other vehicle maintenance tasks, such as engine oil 
and filter changes, that are conducted on an annual basis per FMCSR 
396.17. The CSA group, which maintains NGV 2, is considering 
modifying the inspection interval in NGV 2 to an annual inspection 
following the NGVAmerica Technology &Development Committee's 
Guidance document.
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Unfunded Mandates Reform Act

    The Unfunded Mandates Reform Act of 1995 (UMRA) requires Federal 
agencies to prepare a written assessment of the costs, benefits and 
other effects of proposed or final rules that include a Federal mandate 
likely to result in the expenditure by State, local or tribal 
governments, in the aggregate, or by the private sector, of more than 
$100 million annually (adjusted annually for inflation, with base year 
of 1995). UMRA also requires an agency issuing an NPRM or final rule 
subject to the Act to select the ``least costly, most cost-effective or 
least burdensome alternative that achieves the objectives of the 
rule.'' This NPRM would not result in a Federal mandate that will 
likely result in the expenditure by State, local or tribal governments, 
in the aggregate, or by the private sector, of more than $100 million 
annually (adjusted annually for inflation, with base year of 1995).

Executive Order 13609 (Promoting Regulatory Cooperation)

    The policy statement in section 1 of Executive Order 13609 
provides, in part: the regulatory approaches taken by foreign 
governments may differ from those taken by U.S. regulatory agencies to 
address similar issues. In some cases, differences between the 
regulatory approaches of U.S. agencies and those of their foreign 
counterparts might not be necessary and might impair the ability of 
American businesses to export and compete internationally. In meeting 
shared challenges involving health, safety, labor, security, 
environmental, and other issues, international regulatory cooperation 
can identify approaches that are at least as protective as those that 
are or would be adopted in the absence of such cooperation. 
International regulatory cooperation can also reduce, eliminate, or 
prevent unnecessary differences in regulatory requirements.
    The European regulation for CNG vehicles, ECE R.110, ``I. Specific 
components of motor vehicles using compressed natural gas (CNG) and/or 
liquefied natural gas (LNG) in their propulsion system,'' \40\ requires 
a detailed visual inspection of CNG fuel containers on vehicles at 
least every 48 months and after an accident or fire. However, the 
working pressure of CNG fuel containers in Europe is 20 Megapascals 
(MPa) (3,000 pounds per square inch (psi)), while that in the U.S. is 
typically 26 MPa (3,600 psi). The higher container pressure in the U.S. 
necessitates more frequent visual inspections than that conducted in 
Europe. Therefore, NHTSA did not consider harmonizing with ECE R.110.
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    \40\ http://www.unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/2015/R110r3e.pdf.
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Regulation Identifier Number

    The Department of Transportation assigns a regulation identifier 
number (RIN) to each regulatory action listed in the Unified Agenda of 
Federal Regulations. The Regulatory Information Service Center 
publishes the Unified Agenda in April and October of each year. You may 
use the RIN contained in the heading at the beginning of this document 
to find this action in the Unified Agenda.

Plain Language

    Executive Order 12866 requires each agency to write all rules in 
plain language. Application of the principles of plain language 
includes consideration of the following questions:
     Have we organized the material to suit the public's needs?
     Are the requirements in the rule clearly stated?
     Does the rule contain technical language or jargon that 
isn't clear?
     Would a different format (grouping and order of sections, 
use of headings, paragraphing) make the rule easier to understand?
     Would more (but shorter) sections be better?
     Could we improve clarity by adding tables, lists, or 
diagrams?
     What else could we do to make the rule easier to 
understand?
    If you have any responses to these questions, please write to us 
with your views.

[[Page 29155]]

IX. Public Participation

How do I prepare and submit comments?

     To ensure that your comments are correctly filed in the 
Docket, please include the Docket Number found in the heading of this 
document in your comments.
     Your comments must not be more than 15 pages long.\41\ 
NHTSA established this limit to encourage you to write your primary 
comments in a concise fashion. However, you may attach necessary 
additional documents to your comments, and there is no limit on the 
length of the attachments.
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    \41\ 49 CFR 553.21.
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     If you are submitting comments electronically as a PDF 
(Adobe) file, NHTSA asks that the documents be submitted using the 
Optical Character Recognition (OCR) process, thus allowing NHTSA to 
search and copy certain portions of your submissions.
     Please note that pursuant to the Data Quality Act, in 
order for substantive data to be relied on and used by NHTSA, it must 
meet the information quality standards set forth in the OMB and DOT 
Data Quality Act guidelines. Accordingly, NHTSA encourages you to 
consult the guidelines in preparing your comments. DOT's guidelines may 
be accessed at https://www.transportation.gov/regulations/dot-information-dissemination-quality-guidelines.

Tips for Preparing Your Comments

    When submitting comments, please remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Explain why you agree or disagree, suggest alternatives, 
and substitute language for your requested changes.
     Describe any assumptions you make and provide any 
technical information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     To ensure that your comments are considered by the agency, 
make sure to submit them by the comment period deadline identified in 
the DATES section above.
    For additional guidance on submitting effective comments, visit: 
https://www.regulations.gov/docs/Tips_For_Submitting_Effective_Comments.pdf.

How can I be sure that my comments were received?

    If you wish Docket Management to notify you upon its receipt of 
your comments, enclose a self-addressed, stamped postcard in the 
envelope containing your comments. Upon receiving your comments, Docket 
Management will return the postcard by mail.

How do I submit confidential business information?

    If you wish to submit any information under a claim of 
confidentiality, you should submit three copies of your complete 
submission, including the information you claim to be confidential 
business information, to the Chief Counsel, NHTSA, at the address given 
above under FOR FURTHER INFORMATION CONTACT. In addition, you should 
submit a copy, from which you have deleted the claimed confidential 
business information, to the docket at the address given above under 
ADDRESSES. When you send a comment containing information claimed to be 
confidential business information, you should include a cover letter 
setting forth the information specified in our confidential business 
information regulation. (49 CFR part 512)

Will the agency consider late comments?

    We will consider all comments received before the close of business 
on the comment closing date indicated above under DATES. To the extent 
possible, we will also consider comments that the docket receives after 
that date. If the docket receives a comment too late for us to consider 
in developing a final rule (assuming that one is issued), we will 
consider that comment as an informal suggestion for future rulemaking 
action.

How can I read the comments submitted by other people?

    You may read the comments received by the docket at the address 
given above under ADDRESSES. The hours of the docket are indicated 
above in the same location. You may also see the comments on the 
internet. To read the comments on the internet, go to http://www.regulations.gov. Follow the online instructions for accessing the 
dockets.
    Please note that even after the comment closing date, we will 
continue to file relevant information in the docket as it becomes 
available. Further, some people may submit late comments. Accordingly, 
we recommend that you periodically check the Docket for new material. 
You can arrange with the docket to be notified when others file 
comments in the docket. See www.regulations.gov for more information.

List of Subjects in 49 CFR Part 571

    Imports, motor vehicles, motor vehicle safety.

    In consideration of the foregoing, NHTSA proposes to amend 49 CFR 
part 571 as follows:

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

0
1. The authority citation for part 571 continues to read as follows:

    Authority:  49 U.S.C. 322, 30111, 30115, 30117, and 30166; 
delegation of authority at 49 CFR 1.95.

0
2. In Sec.  571.304, revise paragraph S7.4(g) to read as follows.

 Sec.  571.304  Standard No. 304; Compressed natural gas fuel container 
integrity.

* * * * *
    S7.4 * * *
    (g) The statement: ``This container should be visually inspected 
for damage and deterioration after a motor vehicle accident or fire, 
and either (a) at least every 12 months when installed on a vehicle 
with a GVWR greater than 4,536 kg or (b) at least every 36 months or 
36,000 miles, whichever comes first, when installed on a vehicle with a 
GVWR less than or equal to 4,536 kg.''
* * * * *

    Issued in Washington, DC, under authority delegated in 49 CFR 
1.95 and 501.5.
Heidi Renate King,
Deputy Administrator.
    The following appendix will not appear in the Code of Federal 
Regulations.

X. Appendix to the Preamble: Regulatory History of the CNG Visual 
Inspection Label Requirement

    NHTSA first proposed a visual inspection label requirement for 
CNG fuel containers in a Supplemental Notice of Proposed Rulemaking 
(SNPRM) on December 19, 1994.\42\ The original language proposed for 
the visual inspection label stated that a CNG fuel container should 
be periodically inspected at least every 36 months but did not 
include a mileage requirement, which was consistent with American 
National Standards Institute (ANSI) Natural Gas Vehicle (NGV) 
guidelines at that time.\43\
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    \42\ 59 FR 65299, December 19, 1994.
    \43\ ANSI NGV 2--Compressed Natural Gas Vehicle Fuel Containers. 
Section 2.1.3 Periodic In-Service Inspection states, ``Each 
container shall be visually inspected at least every 36 months, or 
at the time of any re-installation, for external damage and 
deterioration.''

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[[Page 29156]]

    NHTSA received several comments in response to the SNPRM, which 
the agency incorporated into its November 24, 1995 final rule 
establishing the visual inspection label requirement.\44\ First, in 
response to comments by Navistar and a 1994 publication by the 
Natural Gas Vehicle Coalition entitled ``Natural Gas Vehicle 
Inspection Program,'' the agency lowered the time interval on the 
inspection label to 12 months. This change was intended to reduce 
the possibility that damage caused by external factors would go 
undetected and lead to container failure. In addition, in response 
to comments by Ford, the final rule included a mileage interval in 
addition to a time interval because mileage exposure could also be a 
factor in leading to premature container failure due to exterior 
damage. We explained in the final rule that we selected a 12-month 
or 12,000-mile interval because it was consistent with the 
recommended interval for many motor vehicle warranties and routine 
maintenance items. As a result of these changes, the final rule 
required that the visual inspection label state that CNG fuel 
container should be visually inspected for damage and deterioration 
at least every 12 months or 12,000 miles, whichever comes first.
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    \44\ 60 FR 57943.
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    After issuing the November 24, 1995 final rule, NHTSA received 
several petitions for reconsideration requesting that the CNG fuel 
container inspection interval on the CNG fuel container label be 
changed to every 36 months instead of every 12 months. The 
petitioners argued that a 36-month time interval for visual 
inspections harmonized with draft international standards, and 
moreover that field data suggested that an annual visual inspection 
time interval would not have prevented any known container failures. 
The petitioners also expressed concern about the additional cost of 
annual inspections and the increased risk of container damage due to 
frequent inspections that require disassembly and assembly of 
components.
    In response to these petitions, the visual inspection label was 
amended in a final rule issued on September 6, 1996, which changed 
the label's visual inspection statement to the current interval of 
``36 months or 36,000 miles, whichever comes first.'' \45\ NHTSA 
explained in the September 6, 1996 final rule that while visual 
inspection of a CNG fuel container may detect some conditions that 
indicate a potential failure, the Agency agreed with the petitioners 
that a 12-month or 12,000 mile inspection interval would be 
excessive. Moreover, the Agency noted that a 12-month inspection 
interval would not have prevented two publicized CNG fuel container 
failures because they were caused by stress corrosion cracking which 
is internal to the container and therefore would not have been 
identifiable during a visual inspection of the container's exterior. 
The agency also explained that a time interval of 36 months was 
consistent with industry and voluntary international standards.\46\
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    \45\ 61 FR 47086, September 6, 1996 final rule.
    \46\ Specifically, the redrafted the Natural Gas Vehicle 
Coalition (NGVC) voluntary standard and the draft International 
Standards Organization (ISO) standard for CNG cylinder inspection.
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    NHTSA has not amended the statement on the visual inspection 
label required under S7.4(g) since the September 6, 1996 final rule.

[FR Doc. 2019-12895 Filed 6-20-19; 8:45 am]
 BILLING CODE 4910-59-P