The Ely miner. [volume] (Ely, Minn.) 1895-1986, 1927-10-21
GRAVEL ROAD UPKEEP
COST SHOWS INCREASE

SOSl SHOWS lNCNEASE
That Minnesota is not the only
state that is finding it increasingly
expensive to maintain gravel roads
where travel is heavy, is indicated
by an article in "Public Roads," a
journal of highway research pub
lished by the u. S. Bureau of Pub
lie Roads. Many states, according
to the article, are facing a deferred
maintenance" charge because they
have not taken into account the an
nual loss of gravel. It says, in part !:
"Fine crushed rock and graveled
roads, by systematic maintenance.
gay be kept smooth under modern
automobile traffic more readily than
surfaces of coarse material. The
wear under traffic and weather.
however, is rapid. Vari-
GUS state highway departments nave
estimated that the approximate
wear by the interval between re-
surfacing operations and the amount
of material added over series of
years, and these estimates indicate
that the loss of material is large.
wyoming and Colorado report an
inch of material lost per year under
traffic of zoo to 3OU vehicles per
Jay and even higher losses in dis
Lricts where wind is unusually
severe. Wisconsin reports a loss
of l to l " inches per year for
.ramc of 5VO vehicles per day, and
oregon and California confirm the
Wisconsin figure.
"A loss of one inch of compacted
material on an eighteen foot road
represents approximately 400 cubic
yards of loose material per mile
which will cost from $500 to 81 200
20 replace.
Assuming a daily traffic of only
200 vehicles, loss of one-half inch
per year at $3.50 per cubic yard,
loose measurement, and disregarding
interest, the annual cost of main
oaining. mile of fine crushed rock
CT gravel surface may be estimated
as follows: Ordinary maintenance,
300 per year; replacement, 2OO
cubic yards at $3.50, 500; total,
500. This is $3.50 per daily We
nIcle or nearly cent per vehicle
mile. This illustration is not neces-
sarily an average case, but it shows
that the amounts spent year by year
do not represent the ultimate MAIN
tenance costs.
with good road metal and a
moist but not excessively rainy eli
mate the replacement cost ma be
lower than above estimated. With
poor material and an arid climate
It will be much niger. 1t will be an
extraordinary case where the item
Of replacing destroyed material is
not as high as ordinary maintenance
and frequently it may be two to
four times as much. 1t is an item
frequently overlooked in fixing an
nual budgets, accommodating as de
Ierred maintenance until resurfac-
ing is required.
'iMetal is moved from the
ground in two forms: % Particles
thrown to shoulders; and (2) dust
produced by grinding of stone on
stone. A considerable portion of
this consists of particles thrown
from the road; and the dust is a
menace to the travelling public. 1t
is intensely diagreeable to heavily
travelled road; sometimes causing ac-
cidents by the obscuring of vision;
and damaging cylinders and hear
ings in motor vehicles, and causing
serious financial loss, where the road
is bordered by farms, villages or
resorts,
sAnother objection to the fine
crushed rock or gravel type arises
from excessive tire wear and rather
high tractive resistance. Measure
ments made during the past three
years by the State College of Wash
ington indicate that tire wear from
four to five times as great as that
caused by concrete or asphaltic con-
crete surfaces may be caused by UNI
treated fine crushed rock surfaces
upon which loose mulch is main
tanned. Similar studies at the Iowa
State college indicate that the gaso-
line consumption may be one-fourth
more on a gravel road than upon
hard pavement. A similar relation
presumably prevails between fine
crushed and oil treated roads,"
Minnesota has better and more
abundant supplies of gravel than
most other states, and the cost is
less. But only a very few trunk
highways carry less than 200 cars
per day, and 5000 miles of un-
paved roads carry more than 500
cars per day. Is it any wonder
that maintenance of gravel roads is