[Federal Register Volume 59, Number 193 (Thursday, October 6, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-24747]
[[Page Unknown]]
[Federal Register: October 6, 1994]
_______________________________________________________________________
Part V
Department of Transportation
_______________________________________________________________________
Federal Highway Administration
_______________________________________________________________________
Truck Size and Weight; Vehicle Size and Weight Limits in Metric Units;
Notice
DEPARTMENT OF TRANSPORTATION
Federal Highway Administration
[FHWA Docket No. 94-20]
Truck Size and Weight; Vehicle Size and Weight Limits in Metric
Units
AGENCY: Federal Highway Administration (FHWA), DOT.
ACTION: Notice of interpretation; opportunity for comments.
-----------------------------------------------------------------------
SUMMARY: The FHWA has initiated a phased 5-year plan to convert its
activities and business operations to the Metric System of Measurements
as required by the 1988 amendments to the Metric Conversion Act of
1975. Details of the FHWA metric conversion policy and plan were
published in the Federal Register on June 11, 1992 (57 FR 24843). The
plan calls for the conversion to be completed by September 30, 1996.
FHWA regulations currently specify vehicle size and weight limits and
certain distances in English units. This notice converts the most
commonly used of these units to their metric equivalents and provides
guidance for the public to make similar conversions.
DATES: Comments on this interpretation should be submitted by January
4, 1995.
ADDRESSES: Submit written, signed comments to the FHWA Docket No. 94-
20, Room 4232, HCC-10, Office of Chief Counsel, Federal Highway
Administration, 400 Seventh Street SW., Washington, DC 20590. All
comments received will be available for examination at the above
address from 8:30 a.m. to 3:30 p.m., e.t., Monday through Friday,
except Federal holidays. Those desiring notification of receipt of
comments must include a self-addressed, stamped postcard.
FOR FURTHER INFORMATION CONTACT: Mr. Thomas Klimek, Office of Motor
Carrier Information Management, (202) 366-2212 or Mr. Charles Medalen,
Office of the Chief Counsel, (202) 366-1354, Federal Highway
Administration, Department of Transportation, 400 Seventh Street SW.,
Washington, DC 20590. Office hours are from 7:45 a.m. to 4:15 p.m.,
e.t., Monday through Friday, except Federal holidays.
SUPPLEMENTARY INFORMATION: The English unit values for Federal size
(length and width) and weight limits are set by law (49 U.S.C. app.
2311, 2316 and 23 U.S.C. 127, respectively). The conversion of these
values to metric equivalents is not intended to change the law.
However, public acceptance of the metric system will be considerably
delayed unless regulatory limits are reasonably easy to use, remember,
and enforce.
The Congress enacted the current single-axle, tandem-axle, and
gross weight limits--20,000, 34,000, and 80,000 pounds, respectively--
for economic and engineering reasons, but it obviously chose round
numbers to promote compliance and ease of enforcement. That policy is
also embodied in the Bridge Formula, where calculated weights must be
rounded to the nearest 500 pounds [23 U.S.C. 127(a)], producing a
weight table with increments of exactly 500 or 1,000 pounds. In other
words, the legal limit could be nearly 250 pounds higher or lower than
the figure generated by the formula. The Congress balanced its interest
in establishing precise and accurate weight limits with the need to
make a complex proposal more workable. Similarly, the FHWA believes
that some compromises are necessary to reconcile the statutory mandates
to enforce size and weight limits denominated in English units with the
goal to promote conversion of all measurements to the metric system.
Consider, for example, the maximum weight for a tandem axle, 34,000
pounds. The precise metric equivalent is 15,422.4 kilograms. Converting
to a fractional value is obviously impractical, and the nearest whole
kilogram is an awkward number also. One kilogram represents 65 ten-
thousandths of 1 percent (.0065 percent) of 15,422 kilograms. In an
industry where scales are considered acceptable if they are accurate to
within 0.2 percent, 1 kilogram has little meaning. Similarly, a 48-foot
trailer is 14.6304 meters long. Enforcement officers are not in a
position to measure ten-thousandths of a meter, but all Metric devices
for measuring length are calibrated in hundredths of a meter.
With this in mind, the FHWA has decided, for purposes of enforcing
Federal weight law, to allow the rounding of weight values up or down
to the nearest whole number of kilograms evenly divisible by 10; this
gives a margin of error of about 5 kilograms. In the example above, the
15,422.4 kilogram tandem-axle limit would, therefore, be rounded down
to 15,420 kilograms. Five kilograms, just over 11 pounds, are well
within the 0.1 percent margin of error allowed by the National
Institute of Standards and Technology for a new certified truck scale.
Such a scale could have a margin of error of 20 pounds when weighing a
20,000-pound single axle, 34 pounds when weighing a 34,000-pound tandem
axle, and proportionally more for heavier loads. The FHWA believes that
this conversion standard will ease the transition to the metric system
while ensuring that the weight standards established by the Congress
are enforced. We anticipate that implementation of this conversion
standard will have no effect on current loading and enforcement
practices, as no change in current weight regulations is intended.
The FHWA also will allow the measurement of dimensional values to
the nearest one-hundreth of a meter. A 48-foot trailer, therefore,
would be 14.63 meters long. Since dimensions do not fluctuate like
vehicle weights, the FHWA anticipates fewer problems in enforcing these
limits. The rule establishing a vehicle width of 2.6 meters as the
legal equivalent of 102 inches, 23 CFR 658.15(a) remains unchanged.
The metric weight table (appendix A) yields values more precise
than those resulting from the rounding method described in this notice.
For example, the table shows that a three-axle vehicle with a 32-foot
(or 9.75 meter) wheelbase has a gross weight limit of 27,216 kilograms;
States may round this figure to 27,220 kilograms. The values in the
table have not been rounded, however, because the FHWA will not require
States to further round Federal weight standards if they choose not to
do so. The metric values in the table represent the conversion of
English units which have already been rounded one time as discussed
earlier.
This notice supersedes the FHWA's previous policy. In a May 16,
1994, letter to the Florida Department of Transportation, which was
transmitted to the other States, the Associate Administrator for Motor
Carriers announced that the Agency intended ``to use as precise
conversions as possible to determine the metric equivalent to the
English unit.'' After further consideration, the FHWA has determined
that the rounding methods described above are consistent with the
requirements of Federal law and will reduce the difficulties inherent
in switching from English to metric units.
With regard to terminology, the FHWA is aware that the correct
technical equivalent for an English ``weight'' limit would be a metric
``mass'' limit. However, because of its historic and widespread use,
the term ``weight limits,'' when referring to commercial motor
vehicles, will be retained for the present time.
The FHWA will use the following conversion factors, as established
by the American Society for Testing and Materials (ASTM) in its
Standard ASTM E380, ``Standard Practice for Use of the SI International
System of Units,'' to arrive at metric equivalent measurements:
------------------------------------------------------------------------
Weight Distance and dimensions
------------------------------------------------------------------------
1 pound = 0.4536 kilograms......... 1 mile = 1.609 kilometers.
1 Metric ton = 2,205 pounds........ 1 foot = 0.3048 meters.
1 Metric ton = 1,000 kilograms..... 1 inch = 25.4 millimeters.
------------------------------------------------------------------------
Conversion and Rounding
When converting mixed size or weight units, e.g., feet and inches,
to the metric equivalent, reduce the measurement to the smaller unit
before converting to metric and rounding. For example, 10 feet, 3
inches equals 123 inches; 123 inches multiplied by 25.4 millimeter/inch
equals 3,124.2 millimeters; round to 3120 millimeters or 3.12 meters.
Converting Part 658 to Metric Measurements
The metric equivalent of every English unit of measurement which is
used in 23 CFR part 658 and which applies in all States is provided in
the following table:
Conversions of Weight Quantities
------------------------------------------------------------------------
Metric
Quantity equivalent
------------------------------------------------------------------------
1 lb.................................................. 0.4536 kg.
1,000 lbs............................................. 450 kg.
20,000 lbs............................................ 9,070 kg.
34,000 lbs............................................ 15,420 kg.
80,000 lbs............................................ 36,290 kg.
------------------------------------------------------------------------
Conversions of Dimensional Quantities
------------------------------------------------------------------------
Quantity Metric equivalent
------------------------------------------------------------------------
3 inches......................................... 76 millimeters.
27 inches........................................ 0.69 meters.
3 feet........................................... 0.91 meters.
40 inches........................................ 1.02 meters.
4 feet........................................... 1.22 meters.
96 inches........................................ 2.44 meters.
102 inches....................................... 2.6 meters.*
108 inches....................................... 2.74 meters.
12 feet.......................................... 3.66 meters.
28 feet.......................................... 8.53 meters.
28.5 feet........................................ 8.69 meters.
34 feet.......................................... 10.36 meters.
36 feet.......................................... 10.97 meters.
41 feet.......................................... 12.5 meters.
45 feet.......................................... 13.72 meters.
48 feet.......................................... 14.63 meters.
60 feet.......................................... 18.29 meters.
65 feet.......................................... 19.81 meters.
75 feet.......................................... 22.86 meters.
------------------------------------------------------------------------
*An exception to the standard conversion process established by 23 CFR
658.15(a).
Other conversions
------------------------------------------------------------------------
Metric
Quantity equivalent
------------------------------------------------------------------------
1 mile................................................ 1.61 km.
500 pounds per inch................................... 8930 kg/m.
------------------------------------------------------------------------
Metric Equivalent of the Federal Bridge Formula
The Federal Bridge Formula found in 23 U.S.C. 127 is an integral
part of the limits placed on vehicle weight. The Bridge Formula in
English units is as follows:
TN06OC94.013
W=The maximum weight in pounds that can be carried on a group of two or
more axles to the nearest 500 pounds.
L=The distance in feet between the outer axles of any two or more
consecutive axles.
N=The number of axles being considered.
Because the statute requires the use of English units to calculate
Bridge Formula limits, a metric formula is not really possible.
However, appendix A reproduces in English and the equivalent metric
units the weight table generated by the Bridge Formula. The values in
this table reflect the FHWA's policy of rounding down when calculated
weights fall exactly halfway between 500-pound increments. Because the
Bridge Formula is designed to protect the highway infrastructure, the
agency has determined that this conservative policy is consistent with
the statutory mandate.
Congress decided to adopt the metric system nearly 20 years ago. A
notice of proposed rulemaking would serve no purpose since conversion
to that standard is the policy of the United States. There may be
errors in the data published in this notice, however, and the FHWA has
therefore established a docket to receive technical comments on these
provisions. The interpretations will be corrected as necessary, and in
case of omissions, consideration will be given to additional
interpretations.
(Sec. 123, Pub. L. 95-599, 92 Stat. 2701; 23 U.S.C. 127, 141, and
315; 49 U.S.C. 31111-31114; and 49 CFR 1.48.
Issued on: September 30, 1994.
Rodney E. Slater,
Federal Highway Administrator.
TN06OC94.014
Appendix A--Permissible Gross Loads for Vehicles in Regular Operation\1\
Distance in feet (L) (column 1) and meters (m) (column
2) between extremes of any group of 2 or more Maximum load in pounds (lb) and kilograms (kg) carried
consecutive axles on any group of 2 or more consecutive axles\2\
Axles 3 Axles 4 Axles 5 Axles
Column 1 Column 2 ---------------------------------------------------------------------------------------
lb kg lb kg lb kg lb kg
4.................................................... 1.22 34,000 15,422 ......... ......... ......... ......... ......... .........
5.................................................... 1.52 34,000 15,422 ......... ......... ......... ......... ......... .........
6.................................................... 1.83 34,000 15,422 ......... ......... ......... ......... ......... .........
7.................................................... 2.13 34,000 15,422 ......... ......... ......... ......... ......... .........
8.................................................... 2.44 34,000 15,422 34,000 15,422 ......... ......... ......... .........
8.01................................................. 2.44 38,000 17,237 42,000 19,051 ......... ......... ......... .........
9.................................................... 2.74 39,000 17,690 42,500 19,278 ......... ......... ......... .........
10................................................... 3.05 40,000 18,144 43,500 19,732 ......... ......... ......... .........
11................................................... 3.35 ......... ......... 44,000 19,958 ......... ......... ......... .........
12................................................... 3.66 ......... ......... 45,000 20,412 50,000 22,680 ......... .........
13................................................... 3.96 ......... ......... 45,500 20,639 50,500 22,907 ......... .........
14................................................... 4.27 ......... ......... 46,500 21,092 51,500 23,360 ......... .........
15................................................... 4.57 ......... ......... 47,000 21,319 52,000 23,587 ......... .........
16................................................... 4.88 ......... ......... 48,000 21,773 52,500 23,814 58,000 26,309
17................................................... 5.18 ......... ......... 48,500 22,000 53,500 24,268 58,500 26,536
18................................................... 5.49 ......... ......... 49,500 22,453 54,000 24,494 59,000 26,762
19................................................... 5.79 ......... ......... 50,000 22,680 54,500 24,721 60,000 27,216
20................................................... 6.10 ......... ......... 51,000 23,134 55,500 25,175 60,500 27,443
21................................................... 6.40 ......... ......... 51,500 23,360 56,000 25,402 61,000 27,670
22................................................... 6.71 ......... ......... 52,500 23,814 56,500 25,628 61,500 27,896
23................................................... 7.01 ......... ......... 53,000 24,041 57,500 26,082 62,500 28,350
24................................................... 7.32 ......... ......... 54,000 24,494 58,000 26,309 63,000 28,577
25................................................... 7.62 ......... ......... 54,500 24,721 58,500 26,536 63,500 28,804
26................................................... 7.92 ......... ......... 55,500 25,175 59,500 26,989 64,000 29,030
27................................................... 8.23 ......... ......... 56,000 25,402 60,000 27,216 65,000 29,484
28................................................... 8.53 ......... ......... 57,000 25,855 60,500 27,443 65,500 29,711
29................................................... 8.84 ......... ......... 57,500 26,082 61,500 27,896 66,000 29,938
30................................................... 9.14 ......... ......... 58,500 26,536 62,000 28,123 66,500 30,164
31................................................... 9.45 ......... ......... 59,000 26,762 62,500 28,350 67,500 30,618
32................................................... 9.75 ......... ......... 60,000 27,216 63,500 28,804 68,000 30,845
33................................................... 10.06 ......... ......... ......... ......... 64,000 29,030 68,500 31,072
34................................................... 10.36 ......... ......... ......... ......... 64,500 29,257 69,000 31,298
35................................................... 10.67 ......... ......... ......... ......... 65,500 29,711 70,000 31,752
36................................................... 10.97 ......... ......... ......... ......... 66,000 29,938 70,500 31,979
37................................................... 11.28 ......... ......... ......... ......... 66,500 30,164 71,000 32,206
38................................................... 11.58 ......... ......... ......... ......... 67,500 30,618 71,500 32,432
39................................................... 11.89 ......... ......... ......... ......... 68,000 30,845 72,500 32,886
40................................................... 12.19 ......... ......... ......... ......... 68,500 31,072 73,000 33,113
41................................................... 12.50 ......... ......... ......... ......... 69,500 31,525 73,500 33,340
42................................................... 12.80 ......... ......... ......... ......... 70,000 31,752 74,000 33,566
43................................................... 13.11 ......... ......... ......... ......... 70,500 31,979 75,000 34,020
44................................................... 13.41 ......... ......... ......... ......... 71,500 32,432 75,500 34,247
45................................................... 13.72 ......... ......... ......... ......... 72,000 32,659 76,000 34,474
46................................................... 14.02 ......... ......... ......... ......... 72,500 32,886 76,500 34,700
47................................................... 14.33 ......... ......... ......... ......... 73,500 33,340 77,500 35,154
48................................................... 14.63 ......... ......... ......... ......... 74,000 33,566 78,000 35,381
49................................................... 14.94 ......... ......... ......... ......... 74,500 33,793 78,500 35,608
50................................................... 15.24 ......... ......... ......... ......... 75,500 34,247 79,000 35,834
51................................................... 15.54 ......... ......... ......... ......... 76,000 34,474 80,000 36,288
52................................................... 15.85 ......... ......... ......... ......... 76,500 34,700 80,500 36,515
53................................................... 16.15 ......... ......... ......... ......... 77,500 35,154 81,000 36,742
54................................................... 16.46 ......... ......... ......... ......... 78,000 35,381 81,500 36,968
55................................................... 16.76 ......... ......... ......... ......... 78,500 35,608 82,500 37,422
56................................................... 17.07 ......... ......... ......... ......... 79,500 36,061 83,000 37,649
57................................................... 17.37 ......... ......... ......... ......... 80,000 36,288 83,500 37,876
58................................................... 17.68 ......... ......... ......... ......... ......... ......... 84,000 38,102
59................................................... 17.98 ......... ......... ......... ......... ......... ......... 85,000 38,556
60................................................... 18.29 ......... ......... ......... ......... ......... ......... 85,500 38,783
--------------------------------------------------------------------------------------------------------------------------------------------------------
6 Axles 7 Axles 8 Axles 9 Axles
Column 1 Column 2 ---------------------------------------------------------------------------------------
lb kg lb kg lb kg lb kg
--------------------------------------------------------------------------------------------------------------------------------------------------------
61................................................... 18.59 90,500 41,051 95,500 43,319 101,000 45,814 106,500 48,308
62................................................... 18.90 91,000 41,278 96,000 43,546 101,500 46,040 107,000 48,535
63................................................... 19.20 92,000 41,731 96,500 43,772 102,000 46,267 107,500 48,762
64................................................... 19.51 92,500 41,958 97,500 44,226 102,500 46,494 108,000 48,989
65................................................... 19.81 93,000 42,185 98,000 44,453 103,000 46,721 108,500 49,216
66................................................... 20.12 93,500 42,412 98,500 44,680 103,500 46,948 109,000 49,442
67................................................... 20.42 94,000 42,638 99,000 44,906 104,500 47,401 109,500 49,669
68................................................... 20.73 95,000 43,092 99,500 45,133 105,000 47,628 110,000 49,896
69................................................... 21.03 95,500 43,319 100,000 45,360 105,500 47,855 111,000 50,350
70................................................... 21.34 96,000 43,546 101,000 45,814 106,000 48,082 111,500 50,576
71................................................... 21.64 96,500 43,772 101,500 46,040 106,500 48,308 112,000 50,803
72................................................... 21.95 97,000 43,999 102,000 46,267 107,000 48,535 112,500 51,030
73................................................... 22.25 98,000 44,453 102,500 46,494 107,500 48,762 113,000 51,257
74................................................... 22.56 98,500 44,680 103,000 46,721 108,500 49,216 113,500 51,484
75................................................... 22.86 99,000 44,906 103,500 46,948 109,000 49,442 114,000 51,710
76................................................... 23.16 99,500 45,133 104,500 47,401 109,500 49,669 114,500 51,937
77................................................... 23.47 100,000 45,360 105,000 47,628 110,000 49,896 115,500 52,391
78................................................... 23.77 101,000 45,814 105,500 47,855 110,500 50,123 116,000 52,618
79................................................... 24.08 101,500 46,040 106,000 48,082 111,000 50,350 116,500 52,844
80................................................... 24.38 102,000 46,267 106,500 48,308 111,500 50,576 117,000 53,071
81................................................... 24.69 102,500 46,494 107,000 48,535 112,500 51,030 117,500 53,298
82................................................... 24.99 103,000 46,721 108,000 48,989 113,000 51,257 118,000 53,525
83................................................... 25.30 104,000 47,174 108,500 49,216 113,500 51,484 118,500 53,752
84................................................... 25.60 104,500 47,401 109,000 49,442 114,000 51,710 119,000 53,978
85................................................... 25.91 105,000 47,628 109,500 49,669 114,500 51,937 120,000 54,432
86................................................... 26.21 105,500 47,855 110,000 49,896 115,000 52,164 120,500 54,659
87................................................... 26.52 106,000 48,082 110,500 50,123 115,500 52,391 121,000 54,886
88................................................... 26.82 107,000 48,535 111,500 50,576 116,500 52,844 121,500 55,112
89................................................... 27.13 107,500 48,762 112,000 50,803 117,000 53,071 122,000 55,339
90................................................... 27.43 108,000 48,989 112,500 51,030 117,500 53,298 122,500 55,566
91................................................... 27.74 108,500 49,216 113,000 51,257 118,000 53,525 123,000 55,793
92................................................... 28.04 109,000 49,442 113,500 51,484 118,500 53,752 123,500 56,020
93................................................... 28.35 110,000 49,896 114,000 51,710 119,000 53,978 124,500 56,473
94................................................... 28.65 110,500 50,123 115,000 52,164 119,500 54,205 125,000 56,700
95................................................... 28.96 111,000 50,350 115,500 52,391 120,500 54,659 125,500 56,927
96................................................... 29.26 111,500 50,576 116,000 52,617 121,000 54,886 126,000 57,154
97................................................... 29.57 112,000 50,803 116,500 52,844 121,500 55,112 126,500 57,380
98................................................... 29.87 113,000 51,257 117,000 53,071 122,000 55,339 127,000 57,607
99................................................... 30.18 113,500 51,484 117,500 53,298 122,500 55,566 127,500 57,834
100.................................................. 30.48 114,000 51,710 118,500 53,752 123,000 55,793 128,000 58,061
101.................................................. 30.78 114,500 51,937 119,000 53,978 123,500 56,020 129,000 58,514
102.................................................. 31.09 115,000 52,164 119,500 54,205 124,500 56,473 129,500 58,741
103.................................................. 31.39 116,000 52,618 120,000 54,432 125,000 56,700 130,000 58,968
104.................................................. 31.70 116,500 52,844 120,500 54,659 125,500 56,927 130,500 59,195
105.................................................. 32.00 117,000 53,071 121,000 54,886 126,000 57,154 131,000 59,422
106.................................................. 32.31 117,500 53,298 122,000 55,339 126,500 57,380 131,500 59,648
107.................................................. 32.61 118,000 53,525 122,500 55,566 127,000 57,607 132,000 59,875
108.................................................. 32.92 119,000 53,978 123,000 55,793 127,500 57,834 132,500 60,102
109.................................................. 33.22 119,500 54,205 123,500 56,020 128,500 58,288 133,500 60,556
110.................................................. 33.53 120,000 54,432 124,000 56,246 129,000 58,514 134,000 60,782
111.................................................. 33.83 120,500 54,659 124,500 56,473 129,500 58,741 134,500 61,009
112.................................................. 34.14 121,000 54,886 125,500 56,927 130,000 58,968 135,000 61,236
113.................................................. 34.44 122,000 55,339 126,000 57,154 130,500 59,195 135,500 61,463
114.................................................. 34.75 122,500 55,566 126,500 57,380 131,000 59,422 136,000 61,690
115.................................................. 35.05 123,000 55,793 127,000 57,607 131,500 59,648 136,500 61,916
116.................................................. 35.36 123,500 56,020 127,500 57,834 132,500 60,102 137,000 62,143
117.................................................. 35.66 124,000 56,246 128,000 58,061 133,000 60,329 138,000 62,597
118.................................................. 35.97 125,000 56,700 129,000 58,514 133,500 60,556 138,500 62,824
119.................................................. 36.27 125,500 56,927 129,500 58,741 134,000 60,782 139,000 63,050
120.................................................. 36.58 126,000 57,154 130,000 58,968 134,500 61,009 139,500 63,277
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\The permissible loads are computed to the nearest 500 pounds as required by statute.
\2\The following loaded vehicle must not operate over H15-44 bridges: 3-S2 (5-axle) with wheelbase less than 38 feet (11.58 meters); 2-S1-2 (5-axle)
with wheelbase less than 45 feet (13.72 meters); 3-3 (6-axle) with wheelbase less than 45 feet; and 7-, 8-, and 9-axle vehicles regardless of
wheelbase.
[FR Doc. 94-24747 Filed 10-5-94; 8:45 am]
BILLING CODE 4910-22-P