The mirror., 1922-04-20
AMERICAN HIGHWAYS
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bitches. If then you would want to mark
off for your own convenience one mile all
that will be necessary is to take stake num-
Der ffty-two measure eighty feet further
and you have mile, there being five thou
sand two hundred and eighty feet in
mile. Each stake is called station and
is designated as station number so and so.
Next they will stake it according to grade
showing on another set of stakes how
much dirt shall be deposited there to build
up to grade or removed here to make
grade, this is specified on the grade stakes
up to one tenth of foot. This work of
surveying has all been done by the time
the contract is awarded. The contract is
then ready for constructing, supervised by
the eagle eye of the County Engineer, who
in turn is watched by the State Engineer,
who is guided by the Federal Commission.
There are principally three kinds Of
roads in Minnesota today not taking into
consideration the ordinary dirt road or the
preparations used on them such as Tarvia,
Light Oil, etc. These are gravel, bituli-
thic and concrete. Gravel is merely sand
and rock substance, weighing approximate
ly 1900 pounds to the cubic yard placed
upon a dirt-graded surface with an al
lowance of about 800 yards to the mile or
yard every three feet. 1t is economical
to construct and maintain and is as dust
less as the general run of soft surface
roads, 1t is not subject to corrosion, frost,
rain or snow and the life is only gone
when the repair crew is negligent There
are many fine examples of this type in
Southern Minnesota. 1t will make an
ideal road where the extremes in heat and
cold are found.
Bitulithic, Oh! what contracts are COM
mitted in thy name. This type of pave
ment is composed Of dirt grade with
from six to eight inches of crushed rock
base rolled with care, upon which is
placed asphalt and tar to about the same
thickness. After the hot asphalt is in place
it is rolled until level and smooth and
later tar composition is placed upon it as
a riding surface, sometimes there is mixed
with the tar a quantity OF small pebbles
similar to that used on roofs. This road
has beyond doubt proven itself "a very
agreeable pavement for time, but it is
subject to corrosion and dipping and be-
comes in the heat sticky and in the winter
Brittle. 1t starts heaving when the frost
leaves the ground and with traffic soon be-
gins to deteriorate and when it starts to go
nothing this side of the North Pole seems
to stop it. Patching is the only feasible
way to replace the holes but its next to
impossible to make the patch stay If you
have ever driven from Minneapolis to the
Auto Club at Savage you will realize what
those holes look like, in fact, l measured
one exactly eight and three quarters inches
deep, measuring the side wall of bitumen.
In some instances no doubt there are ex-
amples of fine pavement of this type, but
where heat and cold are prevalent it has
not stood up. The name bituithc is really
a coined word and is the method applied
which has reverted to name This type
of road will cost approximately twenty
thousand dollars per mile complete con-
sidering the source of supply and the dis
tance necessary to haul the material.
Next in line we have concrete, king of
them ALL Concrete, man concocted ma
terial, is not as brittle as nature material
when set it is composed entirely of cheap
ingredients, cement, gravel, sand and
water. This type is hard to lay, but
equally hard to wear away provided it
was laid with enough care and thought.
1t is beautiful, smooth and dustless and
when reinforced with steel and checked
with expansion strips will outlast any
road. The strip you have all seen cutting