The Washington herald., 1913-10-05
CAUSE OF ROAD FAILURES.

From the Beaumont ErterTris
The Massachusetts Highway Commits
sion. after a full investigation. officially
states in its annual report. recently is
sued, that the greatest cause Of the de-
struction of modern roads is not ths
automobile nor the motor truck, but the
heavily loaded vehicles drawn by horses.
Massachusetts has long had the habit Of
quietly pursuing Investigations and pre-
senting official reports thereon, while
others are discussing and getting ready
to investigate. Its road commission con-
sists Of Col. W. D. Sohier. chairman;
F. D. Kemp and ]. W. Synan. 1t will
be remembered that the first oficial no
tice Of the damage to waterbound mac
adam by automobiles was presented by
the Massachusetts commission in its re-
port for 1907.
In two instances quoted in the cur
rent report thirty to seventy-five teams
a day, carrying three tons or more each
on two and one-half to three inch tires
broke up within a month the side Of the
road on which the loaded teams tray-
e'ed, while the. surface lasted three
months on the other side where the
teams came back empty. For miles be-
yond the ice houses the roads are still
in good condition. These roads are of
macadam treated with heavy asphaIted
oil.
THE traffic study shows that II is not
the number of teams, but heavy teams
two or more horses, and heavy loads
on narrow tires-that cause the failures
A carefully prepared statement as to
the causes of wear and what ceGain
roads will stand is presented as one OF
the results Of the careful trahic study
entered on some years ago by the com
mission. Among the established results
are the following:
good gravel will wear reasonably well
under a daily traffic composed of 50 to "a
light teams. thirty-five to fifty loaded
two or more horse wagons and 100 to I50
automobiles. With a larger number of
automobiles the gravel should be oiled
The oiling presents what is spoken of as
a blanket surface" consisting of heavy
asphalt oil and sand. II the oil be ap-
piled hot, the blanket surface will last
three to five years. if cold, it must be
renewed every year.
Oiled gravel will stand fairly well IN
der 10 to 100 light teams, thirty to fifty
heavy One-horse vehicles, twenty heavy
wagons with two or more horses, and
500 to 100 automobiles daily.
Waterbound macadam will stand under
daily traffic of 10 to 200 light teams.
l75 to 200 heavy one-horse vehicles and
s to 81. perhaps more, heavy wagons with
two or more horses. II even 80 to 100
automobiles per day go over the road at
high speed, dust layers will be service
able. With a really good dust layer the
road will stand 800 to 500 automobiles
daily. although the stones will wear.
Waterbound macadam with an oil and
sand blanket, applied hot, will be eco
nomical with 80 to 800 light teams, - to
100 heavy one-horse vehicles, Is TO 81
heavy wagons with one or more horses
and automobiles up to LOO, or more with
fewer teams and with fifty or more mo-
tor trucks. The larger number OF auto
mobiles seems to keep the oil rolled
down when It would cut up and crumble
under a traffic OF 100 heavy one-horse
vehicles and % or more horse wagons
on narrow tires, such as loaded farm
wagons, ice wagons, loads of wood, &C.