Milford chronicle. [volume] (Milford, Del.) 1878-1974, 1908-05-22
Federal Tests Of the Effects of
Speeding Automobiles.


cloud of foggrey rock dust hunf
to the horizon and marked the
speeding course of the big machine,
was the sight witnessed by travel
ers on the famous conduit road a
dozen miles from Washington on
Thursday, April 20.
The seemingly pronounced VIC
latiOn of the speed ordinances was
countenanced by two ofthe Nation S
federal departments Agriculture
and War; however, the rushing
motor-car having been pressed into
requisiton by L. w. Page, Director
of the Office of Public Roads, and
DR.. Allerton S. Cushman, Assistant
Director, in the effort to determine
the effects of automobile traffic
upon macadam highways, and the
stretch Of thoroughfsre was placed
at their disposal by War Depart
ment officials.
While the racing car and others
of various weights and types made
many trips over the selected stretch
Of a mile and a half at varying
rates Of speed, from S to 6S miles
an hour, a corps of skilled photo
graphers, equipped with the most
modern devices for photographing
vehicles at very high speeds, made
accurate records Of the various
tests.
1t has long been known to high
way engineers that automobiles
were rapidly shortening the lives Of
the rock surface roads Of the world,
and many experiments have been
made in the past six or seven years
to determine the actual cause of
the damage done. To understand
how the soft broad tires Of the mod
ern motor car can work an injury
to a surface that not only with
stands, but improves under the con-
slant passing and repassing Of We
hicles with iron tires, one must be
apprised briefly of the theory on
which, first Tresauget of Limoges,
and later MacAdam Of Ayr, worked
when giving such highways to the
world. They reasoned that road
surfaced with bits Of stone would
improve under wagon traffic because
the iron tires ofthe passing vehicles
would constantly crush the stones
and form rock dust PARTICLES that
those rock dust particles would |
not merely fill in all the interstices
between the stones but would also |
form a surface dust binder; the
and rollings tending to &C.
ment the dust into a shell like sur
face and thus make the entire road |
one traffic withstanding, water
mass.
They reasoned well and wisely
The macadam roads lived up to the
heories Of their inventors and IN.
proved the passing years until Il e
ldvent of the automobile. 1t IVES
)ut a short time after it came into
-ogue that highway engineers in
III civilized lands learned that
lew condition was confronting them
nd that established customs were
icing menaced. The trouble was
quickly traced to the automobile
nd it was studied. It was soon
Ioted that the soft rubber tire was
he highway menace. 1t crushed
10 rock itself and therefor contri-
'uted no quota of the needful sur
ace dust binder, while the tremen-
Gus tractive force of the rear
wheels drew up the dust made by
he iron tired wagons and sent ii
away over adjacent lands.
Those who witnessed the expert
lents of Thursday near the Natl
nal Capital could not doubt for
ioment that the various road ex-
erts all over the world are correct
/ the opinion that very rapidly
riven automobiles are rapidly tear
lg up the surface of the macadam
Dad, for not only were huge clouds
dust lifted into the air and blown
e the road, but careful examina-
on showed that the material under d
lie wheel tracks of the machine rl
as distinctly loosened and ravel- e
d even during the short period of |
ese tests. 4
No such effects were noticeable H
ter the passing of iron tired We a.
cles the series of tests beginning p p
tn the passing of a horse drawn =,
:hicle This was photographed at
it moved along and also as the W
agon tires passed a given mark. Sc
hen the automobiles were sent &c
-er the course. The first was u,
ANY weight touring car moving RI
five miles an hour. A series of
ctures was made of that car on its Al
any journeys at varying rates of -
eed until its maximum of as miles
hour was attained. Then the
'rk was taken up by the huge /
GER, which tore down the road j
st at a speed of so miles an hour,
en- at IS, 90, and finally at IS. r
fairly lifted the road surfacing !
lterial as il sped along. regular