The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1908-05-03
CONGRESS CALLED
ON ROAD PROBLEMS
France Asks Nations to Join in
Finding Way to Save
Macadam
Automobiles Are Greatest Men=
ace to Taorougflfares Built
OF Crushed Rock

WASHINGTON. April 25.-The office
OF public reads OF the department OF
agriculture has recently been conduct
ing z series Of interesting experiments
70 learn the amount OF damage done TO
rock surfaced thoroughfares by auto
mobiles The results prove that the
modern fast moving motor car is the
greatest menace 20 macadam roads
that has ever made its appearance
On some stretches OF Thoroughfare.
especially in New England. where many
broad and smooth roads have been con
structed. the retrogression is not less
than 40 per cent and IL has been forced
upon the director OF the once OF public
roads and upon many highway engt-
neers that If some plan is not speedily
devised for overcoming the bad effects
OF mans latest and most sensational
mode OF land transportation, the none
tzry loss VIII be stupendous and the
good work OF many years viii go for
nsughL
II is not only in America that this
condition prevails The men OF England.
France. Germany. Holland. Belgium and
other countries OF the old world, where
hard surfaced highways are appreci-
ated. have also learned that the big
soft rubber tires OF the automobile are
doing an almost incredible amount OF
harm
FRANCE CALLS CONFERENCE
France has Officially taken cognizance
OF the condition and has called an in
/ ternationai congress 10 meet AZ Paris
October II TO discuss plans for saving
the roads while in no way interfering
with the development OF the autoT1o-
bile. for 70 scientist viii condemn one
worthy civilizing influence because it
temporarily conflicts with another He
viii merely admit that new condition
has arisen and then set on foot an
investigation with the idea OF master
ing IL.
To many II may seem beyond be-
lief that z pneumatic rubber tire can
work any injury 20 \ road composed OF
bits OF crushed flint rock. but IL be-
comes plain when the theory Of such
roads IS explained The macadam road
named after John Louden AacAdan OF
Ayr. Scotland. who was for years high
way surveyor OF Bristol. was first laid
down By the eminent French road en-
zfnee-. -Treszuget of Limoges. who
wisely figured that slowly moving iron
tired wagons would crush dust parti-
cles from the stones OF the roads sur
face, that those particles would be con-
OF the large stones; that every pass
ing wagon would crush them frnler
Into all ruts and inequalities; that rains
would aid and the ultimate result
would be q smooth surfaced water
shedding highway.
NEW CONDITIONS ARISE
Tresauget planned wisely. MacAdam
came two decades later and made
slight change in the laying OF the road
foundation and gave 10 such thorough
fares his name For a century and
quarter the wisdom OF the road en-
gineers OF Limoges and Ayr was 5usti-
fed. Then arose q condition they had
never figured on-a fast moving vehicle
running on broad. soft tires. The roads
began 10 suffer az once for the follow
ing reasons.
The rubber tire. being soft. creates
10 rock dust itself as does the iron
tire ef 2 wagon, and the very life Of
these roads demands a constant supply
OF that material II Is the surface
binder that keeps the road smooth;
cracks filed in. that maintains the
eTenuess and binds the rubole stones
into one inpervious mass. Every iron
tired wheel does its own small quota
OF good by acting as rock dust maker
and z miniature road roller.
The auto whirring along az dizzy
speed simply hattened it's tires against
the ground as II sped and the tractive
force so exerted hurled the precious
rock dust into the air and from where
Il was swept TO the adjacent farms ana
lawns in binding clouds SO pronounced
was the mere dust nuisance created In
many portions OF the country that real
estate decreased in value 70 an appre-
cable extent and farmers complained
that the ever increasing dust on their
fields. vines and trees made 1t i'm
possible for them to sell their harvest
al as good prices as formerly
MANY EXPERIMENTS MADE
When these conditions had been es-
4abItshed b~ scientifically gathered data
me director OF the Office of public roads
set on foot numerous Investigations and
ordered many experiments. the results
OF which Il is believed viii ultimately
urove the automobile 10 be a great ben
-efactor. for in the struggle 70 overcome
the conditions created highway engi-
reers must do one OF two things find
q road surfscfng material which makes
no dust and needs no dust 10 maintain
its integrity. or discover & method OF
controlling the dust on the roads al
ready laid. When that is done one OF
the greatest problems OF the centuries
will have been solved and humanity
will have gained one OF the greatest
blessings imaginable
Absolutely dust proof thoroughfares
would add immeasurably 70 the COM
forts Of the human race: multiply the
beauty OF vast stretches OF country:
add countless millions OF wealth 10 SUBJ
urban and country property and do
much 70 retard disease. for dirt means
disease and the 2.150. 900 miles OF high
ways in the United States make not
less than SO per cent OF the dust which
long suffering people take into their
lungs each year.
To this time no dust proof road sur
face material cheap enough for use in
country districts has been found. and
the experiments now proceeding are
therefore along the second line: the
controlling OF the dust by various meth
ods OF spraying and by the use OF
binder materials
CALIFORNIA POINTS WAY
IN some sections, especially through
the great fruit belts of California
splendid success in dust suppression has
been attained By spraying the dirt roads
with oils possessing asphaltic bases In
other portions of the country the wise
administering OF coal tar preparations
has aided 10 a great extent. and drench-
ing with calcium chloride has shown