Evening star. [volume] (Washington, D.C.) 1854-1972, 1927-01-30
STEINBERC TRACES NEED
! FOR SAFETY ON HIGHWAY
More Than $3.50, 900, 900 Is 1926 Bill for Con-
struction and Maintenance, Says Maryland
University Official in Survey.

/ serve to reduce the annual toll OF
human life and property damage ex
acted on the highway.
Skid Studies Are Made.
"Skidding of tires on wet pavements
is one of the frequent causes of high
way accidents. Investigations at the
| Iowa State College on side skiddfng
of pneumatic tires on various roaC
surface conditions show that on roads
| coated with snow or ice or with oily
slime or mud, the force required to
cause skidding is approximately one
third to one-fourth of that on clean
dry surfaces, while on icy roads that
are thawing a little, the coefficient
may be as low as ne-SiXth of that on
Il clean, dry surface.
Interesting results have been OBJ
| tanned from Investigations on tire
| wear, tractive resistance of road sur
faces and wind resistance of automo'
| biles, each of which are important
| economic factors in highway opera
| ton.
Speed Increases Wear.
Studies on tires conducted at the
State College of Washington show
| that tire wear increases with the
speed of the vehicle and with increase
in temperature, and that rear tires
wear, on the average, so per cent
more rapidly than front tires. These
experiments indicate that under nor
NAL conditions of vehicle loads ana
tire imitation. the relative wear or
tires on different types of roads rep
resents useful mileages of $4,000 on
the best road surface to as low as 2,00O
on the worst Considering that the
l., u
year, the annual tire cost per car
varies from $50 to more than $500, de-
pending upon the type of road surface
the vehicle uses.
"StudieS conducted at the North
Carolina State College on the power
reuuired to drive motor vehicles on
different road surfaces showed that
at Is miles an hour twice the horse
power was needed to propel a vehicle
on a wet and muddy surface as on a
dry and smooth one. Studies of the
effect of speed showed that almost
four times as much power is required
to run the vehicle at 35 miles an
hour as at Is miles an hour.
Wind Effect is Great.
IAN investigation on the effect of
the wind upon a car travelling at va
rious speeds was conducted at the
Iowa State College and the results
confirm those previously obtained at
the Kansas State Agriculture College.
In these experiments 1t was shown
that when you drive your car at IS
miles an hour you use, on the average,
eight horsepower to overcome wind
resistance. If you reduce speed to %
miles an hour, you save five horse
power.
I'm recent years one Of the impor-
tant functions of State highway de-
partments in northern ATTITUDES has
been the removal of snow from their
rural roads to prevent Inconvenience
and economic loss occasioned by block
AIDED highways. In addition to main
tanning traffic through the Winter
months, snow removal saves the road
surfaces from excessive wear during
thaws by distribution Of the traffic
and prevention of ruts.
Snow Removal Cost.
Last Winter $4,000 miles of high
ways in the United States were kept
clear of snow at an average cost of
about $40 a mile. This is an increase
in miles cleared of SO per cent over
the preceding Winter. In many sec
tons where drifts are encountered
snow fences have been constructed
and found effective in keeping the
roads clear.
I'm many sections of the country
highway transportation surveys are
being made. The object of these is to