HomeMy WebLinkAboutAGENDA REPORT 1995 0405 CC REG ITEM 08EST
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DATE:
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AGENDA REPORT
C = TY OF MOORPARK
The Honorable City Council
Kenneth C. Gilbert, Director of Public Works
March 22, 1995 (Council Meeting 4 -5 -95)
DOPPA?K, CALIFu "..
City CounGl aefing
of y 1995-
A N:
SUBJECT: Utilization of Metric Dimensions on Future Street
Improvement Plans
DISCUSSION
A. Background
The United States is one of only three (3) nations in the world
which still uses the Imperial standard of weights and measures.
England, which gave us this system, abandoned it thirty (30)
years ago. As you may be aware, the United States has initiated
and is now in the process of joining the rest of the world by
converting to the Metric System.
B. Caltrans
In California, Caltrans has taken the lead in this effort by
coordinating methods and procedures to be used in converting to
this new system. A copy of document published by Caltrans on
the matter, entitled A Metric Primer, is attached for your
information, as Exhibit 'A'. As of October 1996, all public
works contracts using federal dollars will be required to state
all measurements and quantities in metric values.
C. County of Ventura
Local agencies within Ventura County have been working with the
staff of the County of Ventura Public Works Agency on the
development of new road standards. At some point in the near
future, all subdivision maps, deeds, improvement plans and
related documents will be required to state all measurements in
metric values. For instance, right -of -way widths will be
required to use the revised road standards listed in Exhibit
'B.'
RECOMMENDATION
Receive and file this report.
metric
00033
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.bets Get Metric ;
Welcome to the world of the metric system, or the International
System of Units, often abbreviated as "SI ". Caltrans has the
privilege of leading California into this world.
1=
Actually, the metric system has been around for more than two
a
j centuries. Benjamin Franklin and Thomas Jefferson first proposed
that the US convert to the metric system, but it was more than two
hundred years before another president, George Bush, in 1991, 1 ,;
would sign an executive order to mandate that all agencies using
federal money begin using the standard. i
That's how we got into it. FHWA responded to President .
Bush's order by developing a plan requiring that all agencies
using federal highway dollars begin advertising projects for ,
construction using metric units by October 1, 1996. This booklet is
a part of the Caltrans response to the federal mandate.
Actually, for a technical agency like Caltrans, metricating
shouldn't be such a big deal. Most of our engineers were trained in
the metric system in college. Our surveying equipment is already
in metric and has to convert back to US units to make the data
available. And most engineers prefer to work with orderly and
systematic systems.
r
An international standard, called "ASTM E380 ", provides
guidelines for the proper use of SI. Caltrans has adopted that
standard, except that we use the American spelling of "liter" and
"meter", rather than the French "litre" and "metre ". This booklet,
drawing on ASTM E380, contains basic information for your use in
doing your job. That's why we call it a "primer ". It contains basic A
descriptions of the units, conventions for writing the terms, and w
conventions for rounding and converting from the US system. G
N
0
Your Basic Metric Stuff
The neatest thing about the Metric System is that all units are
based on decimal mathematics. A kilometer is 1000 meters and a
kilogram is 1000 grams (you'll understand later why there are no
commas). No more eight pints to the gallon or 5,280 feet to the
furlongs,
fathoms, rods chains ,
mile. No mils, inches, feet, yards, at 9
or miles. Here are some basics:
Meter (m): The basic measure of distance in the Metric System, a
little longer than a yard.
Kilometer (km): The basic measure of longer distances, a little
longer than a half -mile.
Millimeter (mm): For measuring the little stuff (a dime is about a
millimeter thick). There's a centimeter too -- about a third of an inch
-- but Caltrans probably won't measure in centimeters.
Liter (L): The Metric System's basic measure of liquid, a little
larger than a quart.
Gram (g): For weighing the little stuff. A paper clip weighs about a
gram.
Kilogram (kg): One thousand grams, weighing a little more than
two pounds. The tonne or metric ton, about the weight of a fast
sports car (1000 kilograms), is used for larger weights.
Time (s): The second, the basic measure of time, remains the
same as in the US system.
Ampere (A): The basic measure of electric current, same as in
the US system.
Candela (cd): The basic measure of luminosity.
Temperature (K): The basic measure of temperature. Celsius
temperature ( °C) is used more commonly than kelvin (K), but both
have the same temperature gradients. Celsius temperature is just
273.15 degrees warmer than kelvin ,
which begins ins at absolute
zero. Water freezes at 273.15 K and at 0 °C. To move between
Celsius and kelvin, add or subtract 273.15. It
cm
p The radian (rad) and steradian (sr) denote plane and solid
« angles. They are used in lighting work and in various engineering
W •calculations. In surveying, the units degree (0), minute (') and
M second ( ") continue in use.
2
7erminofogy
Special dames
oo «" Unit Syrnbpl Expression
...1.;; .:....
..
. hertz Hz .
Hz =s
f"�. ' �i:�artru:nt �`i�trli�tli�<<� < >; >;» >:<:, >
newton ! >«N< >< >« N = kg•m/sz
OR
joule J J = Nom
watt:'::::
>Vlt<? »<` >`
W = J/s
pascal
Area
Pa = N /m2
Celsius.:::::::::
Dercu bic
C = A•s
volt :X
0d/M2
V= W /AcrX
ohm
I
Q = V/A
lumen
in
1 = cd-sr
lux
lic
.x = Im/m2'
Derived 'Units
Measurable Attribute Unit I Expression
miter ond s oared : > .
nJ... >!
Area
square meter
m?
Dercu bic
Luminance
candela per square meter
0d/M2
Veloci
meter per second
m/s
C
9
,11
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4
a
w
W
0
1
'I1 k I
4�
MuCtipCication factors
Multiple
Prefix
Symbol
-:
;)ig' a (tas.art, ► a 2t� ::ip. �.... u
mega
_ .
as In mega -phone
1 000 000 = 106
mega
M
heck' toe
�deka
deck` a (a;as in a= bout:
100 = 102
'hecto
h
?0 � t4s.
tdeka.
;cla
0.1 = 10 -1
*decl
d
nan' oh (an as in ant)
0.001 = 10-3
mid
m
0.000 000 001 = 10-9
nano
n
avoid where possible
WScommended Pronunciations
Prefix
Pronunciations
..:.:.::....::::::..:.:..
-:
;)ig' a (tas.art, ► a 2t� ::ip. �.... u
mega
_ .
as In mega -phone
.l 1. ,.
hecto
heck' toe
�deka
deck` a (a;as in a= bout:
deci
as in deci -mal
.............
a s irr.r;ert .
milli
as in mili -tary
mian 77 7
as m mrra :: e
nano
nan' oh (an as in ant)
4
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Drafting for f � Standards ;.
:1
Me tn"C 'Cans
is
• Sheet sizes shall remain the same size until a nationwide
paper change.
0 Stationing shall be based on 100 meters per station.
• Scales
Plan Sheets:
Metric Scale
1:10
1:20
1:20
1 :50
1:50
1:20
1 :50
1:100
1:200 _
1:500
1:500 (urban)
1:1000 ( rural)
1:2000
1:5000
Map grid ticks shall be every 200 -250 mm depending on scale.
Crosshair legs shall be 20 mm long (actual plan dimension).
Profile Sheets:
- Rural sections in hilly or mountainous terrain - 1:100 vertical, D
1:1000 horizontal
- Rural or urban with gentle rolling terrain - 1:50 vertical, 1:500
horizontal o
- Rural or urban with level terrain - 1:20 vertical, 1:200 °O
horizontal
5
i
Writing Conventions
Drafting Standards for Metric Flans, Continued � Use Upright Text
Correct: Bob is running in tomorrow's 10 km race.
Cross Sections: Incorrect: Bob is running in tomorrow's 10 km race.
- Rural - 1:100 `
• Plural Same as Singular
- Urban - 1:50
Correct: To train for the 10 km race, Bob runs 1 km a day.
• Pavement cross slope and superelevation shall be shown as Incorrect: To train for the 10 kms race, Bob runs 1 km a day.
percent. • No Period Follows (except end of sentence)
• Angular measurement shall retain Degree- Minute - Second Correct: After the 10 km race, Bob will walk 1 km.
convention. Incorrect: After the 10 km. race, Bob will walk 1 km,.
• Cross section intervals shall be 20 m. Use Lower -Case (except for abbreviations derived from
• Contour intervals: •' someone's name):
• All survey information shall be expressed in meters. Output of
survey information on Right of Way maps showing property
data may be expressed in dual units, with the primary
expression being in metric units.
• Dual units shall not be allowed on construction plans.
• Side slopes shall be shown as a dimensionless ratio of Y:X
(opposite of existing convention, but consistent with normal
math practices and also adopted by AASHTO).
O
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6
W
aD
:Ct
Un :
Xbr�v>iat
centimeter
.ash
cm
;.._
kilometer
km
ktl r.......
.......liter ..�: ..
kg: ,
.
w
L
. :i7:!•.. : :•.
�yt}w}�ti
1?I* 4a5tk >y
4r
:.:n;..;:w.:.n ...............................................................::<
e to
N:... ........,..,...........,.......
0 ue
J
The symbol "L" is recommended for liter in the United States,
although both "L" and "I" are approved alternative symbols,
since the letter I can easily be confused for the numeral 1.
• Space Between Digit Number and Unit Symbol
Correct: 35 mm
or 250 kg
Incorrect: 35m
or 250kg
Exceptions: 45' and not 45
d 20'C and not 20' C
• No Space Between Prefix or its Symbol and Unit
Correct megapascal MPa
Incorrect mega pascal M Pa
7
BE
0
Conventions (Continued)
• With Symbols:
Use Raised Dot for Product:
N -m for newton meter
- in WordPerfect [character "" = CTRL -V (6,31)]
- in Microsoft Word, COMMAND +OPTION +Q, then
raised dot from symbol chart or ASCII 251
- with tYP ewriter, use period (N.m)
Use Slash or Solidus for Quotient:
.' r m
r
example: meters per second: m/s o m•s o use -j-
With Unit Names
Use Space or Hyphen for Product:
Correct: newton meter, or newton -meter
Incorrect: newtonmeter
Exception: watthour
Use "per" for Quotient (not
Correct: meter per second
Incorrect: meter /second
• Group Digits by Three from Decimal Point. No Comma
Within a Number
IJ$ International (metric)
2fi,a; 26 345
41 2.141 596
In numbers i rs with FOUR its on either side of the decimal a
9
space is not necessary except for uniformity in tables.
Correct: 0.1335 kg or 2345 kg
3
k
Incorrect: 0.133 5 kg or 2 45 9
• Fractions Unnecessary
Correct: 2.5 m
Incorrect: 2 � m
• Use Zero before Decimal Marker
Correct: 0.1234
Incorrect: .1234
4
CD
a
8 W
40
n
Common Conversion Factors to Metric
,�O
Multiply:
Tote.
ft 2
rT12
.:::.:.....
t
m
... .
mi
km
<:: ,.
Y d..,.
m
'<:x::.
W
"€$;`
,.
...
.T
L ..
N
fl oz
mL
d 3
><<
rTT3
acre ft
1S3 49
:..:.:..;:.:..:..::.
oz
8 :35
9
lb
kg
XX
kip (1,000 lb)
t� a:3fi`
tam (1UUUkg)
s
shod ton 2,000 b
.007 2 .........
k
:::..:.
XX. :;
short ton
s
4"l
torine 1000 k
( )
9
3
kgIM3
Ib /ft3
1 :6 Ot85
kg/M3
psi
:$
a
ksi
MPa N /mm
h
2
P
........ .
m/s
.:.
ry
P h
m/s
>: h............
km/h
footcandle
` 1 Q'��4
lux (Ix)
}> >
(or) lumen /ft2
(or) lumen/m2
'rmrtur
OF
t a (t ofl2)t1 8!
°C
For land surveying, see "Land Surveying Conversion Factors" table on
page 10, below
Use Capital "L" for liter to eliminate confusion with the numeral "1 "
E
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44
Land Surveying Conversion Factors
Class
Multiply :
s.y; To Get
Mg/m3
acre
;404f.;�. ::.... rr12
11 :9 $
acr e
>x <: m
ha a 0 000 2
:;.:. ........::.:.
Q�1
mN
ra #arcs)
it
Exact, by definition of the US Survey foot, Section 8610, State of California
Public Resources Code
Less Common Conversion Factors
Clad s Multiply �y ►» To Get:
Ibf /ft3
N/m3
Q @f1Sl ` fytaS :i:
Ib,/in3
7 f>R :. <':;
Mg/m3
may'
lbmigal (US)
11 :9 $
kg/m3
for �.:.<
d
dyne
y
Q�1
mN
ra #arcs)
kgf
N J
:;;.: ::: ::;:.
f
..: :.:.:...:
.......::..... ....... :::
tonne f
kN
t on (metric)
`iii... �...... .
kN
r ri
m c
9
z (avoirdupois)
9
ozm (troy)
:fi.i(:....::
9
Ibm
r.a.ar4
kg
tonm (short) ( Q7:... Mg
The Metric System eliminates the confusion in US terminology about "weight" by
separating it into two definitions: "mass ", and "gravity force ". Mass refers to the
inertia of an object, or the force required to accelerate or deceleratd it in a
gravity-free environment. Gravity force is the net downward force acting on a
stationary object to attract it to another, always proportional to the strength of
the gravitational field and the object's mass.
p.
10
Conversion And sounding
General: I., 4'r-
•
Conversion from US to SI may be either exact ("soft"), or a
suitable approximation ( "hard ").
• In a soft conversion, the US unit is converted to an exact
metric equivalent.
• In a hard conversion, the US unit is converted to a new
rounded, rationalized metric number convenient to work
with.
• In all conversions, use SI equivalents similar in magnitude to
the original. If a 1/16 inch scale was suitable for the original
measurement, a 1 mm metric scale is suitable for the
conversion.
Conversions
• Always establish intended precision as a guide to how many
digits to retain after conversion. The number t . 1 875 may be a
very accurate decimalization �?f ,� r�urrtber that r - -Quid have been
expressed as 1.19. The value - ..ay mear, about 2, or :R
may be a very accurate value of 2, expressed as "2.0000 ".
• The converted dimension should be rounded to a minimum
number of significant digits so the unit of the last place is equal
to or smaller than its conversion.
Example:
Precision of a 6 inch stirring od is estimated at about ' in t '
9 i ( a
in) or, converted, 12.7 mm. The converted dimension, 152.4
mm, should be rounded to the nearest 10 mm and shown as
150 mm.
• Converted values should be rounded to the minimum number
of significant digits in order to maintain the required accuracy.
Example:
A length of 125 ft converts exactly to 38.1 m. But if the 125 ft
length was obtained by rounding to the nearest 5 ft, the
conversion should be given as 38 m; if it had been obtained
by rounding to the nearest 25 ft, the result should be rounded
to 40 m.
"%L.i
11
Conversion and sounding, continued
i
• A stated limit such as "not more than" must be handled so the I�
limit is not violated. "At least 3 inches wide" requires a width of
at least 76.2 mm, or at least 77 mm. ;!
• When converting, multiply a value by a more accurate factor
than required, then round appropriately afterward. Rounding
before multiplying will reduce accuracy.
Example:
When converting 3 feet 2 � inches to meters (T99' = 0.5625 "):
(3 x 0.3048) +(2.5625 x 0.0254) = 0.979 487 5 m, rounds to
0.979 m
Significant Digits
• When converting integral values of units, consider the implied
or required precision of the integral value to be converted.
Example:
The value 'A in." may represent 4, 4.0, 4.00, 4.000 or 4.0000
in
• Any digit necessary to define the specific value or quantity is
significant.
Example:
t
Measured to the nearest 1 m, a recorded distance of 157 m I
would have three significant digits. Measured to the nearest k
0.1 m, a distance of 157.4 m would have four significant digits.
• Zeros may indicate either a specific value or an order of
magnitude. As an example, the population of the United States
in 1970, rounded to thousands, was 203 185 000. The six left- K"
hand digits are significant, each measuring a value. The three
right hand zeros indicate that the number has been rounded to
the nearest thousand.
p Identifying significant digits is only possible by knowing the i
p circumstances by which they were originally arrived at. For
example, if the number 1000 is rounded from 965, only one
zero is significant. If it is rounded from 999.7, all three zeros are
... , significant.
12
K
i
Conversion And mounding, eoi
• When adding or subtracting, the answer
significant digit' to.the right of the least precis
• When multiplying or dividingg the product or quotient must
contain no more significant digits than the fewest significant
digits used in the multiplication or division. �• . �
Example: afi�
113.2 x 1.43 161.876 -- round to 162 bscau a 1.43 has
three significant digits `
113.2 + 1:43 = 79.160 8 - round t ^'0 -1 ` same reason
(Rounding Values
• When the first digit discarded is iess than l dlgi,'
retained Is notffianged.
Example:
3.463 25, rounded to four digits would be 3: - u
three digits, 3 46, x4`
• .. When the first digit discarded is greater than,
by at least bne digit other than 0, add 1 to the,la
Example:��:
8.376 52, rounded to four digits would be 8.37'
three digits 8.38.
• When the first digit discarded is exactly 5 fo
zeros, the last digit retained should be rounder
odd. No adjustment is made if it is an even numl
Example:
z
4.365, rounded to three digits becomes 4.36. Th
would round to the same value, 4.36, if rounded
r
f:
I:
/1' 1
_4,
ounded to
id only
yard if It;Is;;`'
00
_4,
:t
rA
FEATURE
TRAVEL LANES
PARKING LANES
SIDEWALKS
HALF ROAD WIDTH
CL TO CF
RIGHT OF WAY
=D DISTANCES USED IN
U.S.
SI
SI in
FEET
METERS
FEET
9.5
2.9
9.51
11.0
3.3
10.83
l 12.0
3.6
11.81
16.0
4.9
. 16.08
6.5
2.0
I
6.56
7.0
2.1
j 6.891
8.0
2.4
7.87'
10.0
3.0
9.84_:
4.0
1.21
3.94'
! 5.0
1.5
4.92
8.0
2.411
7.87
10.0
3.0
9.84'
16.0
4.91
16.08
51.0
39.0
20.0
18.0
16.0
26.0
118.0
94.0
84.0
84.0
96.0
68.0
60.0
53.0
49.0
45.0
60.0
60.0
r
EXHIBIT B Page I Of 2
R,
DATA FOR COMPARISON
�/2 WIDTH: MEDIAN + TRAVEL
LANES + PARKING LANE
15.3
50.20
7 +3 912 +8
2.1+3@3.6+2.4
11.7
38.39
7 +2 @12 +8
2.1+2@3.6+2.4
6.0
19.69
0+1@12+8
0+1@3.6+2.4
5.41
17.72
0 +1 @11 +7
0 +1 @3.3 +2.1
4.91
16.08
0 +1 @9.5 +6.5
0 +1 @2.9 +2.0
7_91
25.92
0 +1 @16 +10
0 +1 @4.9 +3.0
VENTURA CO.
ROAD STD
PLATE #
35.4
116.14
_
B -2 A
28.21
92.52
B-213
25.2
82.68
B -3 A
25.21
82.68
B -3 B
29.0'
95.14
B -3 B
20.6
67.59
B -3 C
18.0
59.06
B -3 D
16.0
52.49
B -5 A
14.8'
48.56
13-513
13.8
45.28
B -5 C
18.2
59.711
B -7 A
18.2
59.71
13-713
VC - PWA 11/03A
00042
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RIGHT OF WAY (R)
PAVEMENT WIDTH (W)
FLOODING FREE WIDTH (F)
CURB RETURN RADIUS, MIN
CURVE LENGTH, MIN
CURVE LENGTH, MAX
TANGENT BETWEEN CURVES
CURVE LENGTH WITHOUT
SUPERELEVATION
DESIGN SPEED, KPH
STOPPING SIGHT DISTANCE
SIDEWALK WIDTH (INCL CURB)
MEDIAN WIDTH
LOOP LENGTH, MAX
CUL -DE -SAC LENGTH, MAX
(LOT > 0.2 ha)
(LOT > 0.2 ha)
kNDARDS
DIMENSIONS
IN SI
UNV ENS
(METERS
COUNTY
ROAD
STANDARD
PLATE NUMBERS
B -2A
B -2B
B -3A
B -3B1
B-3B
B -3C
B -3D
B -5A
B -5B
B5 -C B -7A
B7 -B
35.4
28.2
25.2
25.2
29.0
13.8
9.8 12.2
12.2
13.2
9.6
19.2
19.2
19.2
15.8
12.0
12.0
10.8
_
7.9
4.3
8.5
8.5
8.5
4.9
1.2
-
-
8
- 8 _
_
10
10
10
14
14
14
14
8
90
75
60 D_2
550
180
180
90
90
90
-
-
800
800
800
8001
800
-
120
120
60
60
69
-
-
-
700
100
400
80
65
65
65
65
50
50
40
40 80
65
90
180
135
90
90
90
90
60
60
50
50 135
2.4
2.4
1.2
1.2
3-4.9
2.4
3.0
1.5
1.5
1.5 i
-
4.21
4.21
I
5001
0 �
, -
ANY
1 ANY
ANY
1 601
ANY
500
1 O i
VG - PWA 11 /03/92
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