The Abbeville press and banner. [volume] (Abbeville, S.C.) 1869-1924, 1915-12-01
TO CHEVY CHASE;
A LESSON IN ROADS
EXPERIMENTAL ROAD OF DIFF
FERENT TYPES PROVES
A SUCCESS

There is at Washington a Text.
Book in Concrete, Brick and Stone
the road to Chevy Chase, built by
the plans and under the direction
of the Office of Public Roads of the
United States and for the sole pur-
pose of informing the public and
the members of Congress interested
in the improvement of the public
highways upon the methods and cost
of construction, types of roads,
adaptability of material and econo.
my of maintenance. Thousands of
people travel over this road, which
is built in many sections of different
types, every day, and hundreds of
practical road-builders from all parts
of the country have inspected it
from time to time and have mar
yelled at the excellence of the work.
Manufacturers who have supplied
bituminous, materials for the treat
ment of the road have detached their
special experts for this service and
the traffic over the road has demon
strated under carefully observed
conditions the relative value of the
several types of road making up
this great highway.
The Chevy Chase Road is expert
mental. 1t consists of different
types of pavement -bituminous ma
cadam laid by the penetration meth
cd, surface treatments of water
bound macadam, asphaltic surfaces
on concrete foundations, bituminous
surfaced concrete, plain and oil
cement concrete and virtrifield brick,
all of which are under daily obser-
vation by expert road5uildecs to as
certain which of the types is best
suited to the traffic and which is
condemned by practical test under
the same conditions of climate, soil,
rainfall, heat and cold and like traf-
fic requirements. 1t would be just
the same to the Office of Public
Roads which has written this open
book in concrete, brick and stone,
whether any part of il or all parts
of it should fail, failure in mater
ials used, in construction, in dura-
bility, in cost, in maintenance-the
test is the thing.
Roadbuilding is a science now and
efficiency is the only test of quail
ty. In the stones used in the con-
struction of the Chevy Chase Road,
their specific gravity, their weight
per cubic foot, their water absorb
ton, their percentage of wear, their
hardness and toughness are all de-
termined by the most careful scien-
tifc tests. Patrolmcn are constant
ly employed on this road to keep
account of whatever defects in ma
terials and construction may develop
and exact data as to the cost Of
maintenance. In one of the ex-
periments covering 1881 square
wards, the cost per square yard for
2k inch bituminous wearing sur
face was 46.18 cents. This expert
ment was made in 1911. For the
maintenance of surface there was
no expense in the. two following
years; but in 1914 this expense
was $79.70. On another section
of the road the cost per square yard
for 21a inch bituminous wearing
surface was 64.42 cents and for
construction 1920.
This experiment covered an area of
of 705 square yards and in the three
years from 1912 to 1914 inclusive,
there was no expense for mainte-
nance. All surfaces on this road
were built of uniform thickness of
8 inches and of a total width of
10 feet. The base course was of
stone ranging in size from to 8
inches spread to a depth of 5 in
ches, the voids being filed with
screenings. The wearing course
consisted of stone ranging from 1
to 2 inches, generally, and upon
this course the bitumen was applied
in two applications of approximate
ly IL to II gallon, respectively.
The cost of the stone used in the
foundation and wearing courses
varied according to the expense Of
quarrying and delivery, as it would
vary at all other points; ard of all
the materials of construction and
charges for maintenance exact ac-
count has been kept.
The Chevy Chase Road was for
tunately placed for the reason that
all of it's sections or types have
been subjected to precisely the same
sort of traffic year in and year out
and the section or type that has
not stood the strain has been as i'm
portant an object lesson to raod-
builders as the section or type that
has maintained itself under like
strain. The road as a whole is a
great experiment conducted by the
most competent engineers to dem
onstrate the most practical things
American Highway Association.